Dinosaurs

@article{buckland1824notice28,
    author = "Buckland, W",
    title = "Notice on the Megalosaurus or great fossil lizard of Stonesfield",
    year = "1824",
    journal = "Transactions of the Geological Society of London, v. 2, no. 1, p. 390-396",
    note = "talkorigins\_source = {true}; raw\_reference = {Buckland, W., 1824, Notice on the Megalosaurus or great fossil lizard of Stonesfield: Transactions of the Geological Society of London, v. 2, no. 1, p. 390-396.}"
}

@misc{eudesdeslongchamps1838mmoire52,
    author = "Eudes-Deslongchamps, J. A",
    title = "Mmoire sur le Poikilopleuron bucklandi, grand saurien fossile, intermdiaire entre les crocodiles et les lezards",
    year = "1838",
    howpublished = "Memoirs de Societe Linnanne de Normandie, v. 6, p. 37-146",
    note = "talkorigins\_source = {true}; raw\_reference = {Eudes-Deslongchamps, J. A., 1838, Mmoire sur le Poikilopleuron bucklandi, grand saurien fossile, intermdiaire entre les crocodiles et les lezards: Memoirs de Societe Linnanne de Normandie, v. 6, p. 37-146.}"
}

@article{openalexw3215057009,
    author = "Owen, Robert P.",
    title = "Report on British fossil reptiles, part II",
    year = "1842",
    journal = "Medical Entomology and Zoology",
    openalex = "W3215057009"
}

@misc{owen1855monograph96,
    author = "Owen, R",
    title = "Monograph of the fossil Reptilia of the Wealden Formations II, Dinosauria",
    year = "1855",
    howpublished = "Palaeontogr. Soc., p. 1-54",
    note = "talkorigins\_source = {true}; raw\_reference = {Owen, R., 1855, Monograph of the fossil Reptilia of the Wealden Formations II, Dinosauria: Palaeontogr. Soc., p. 1-54.}"
}

@inproceedings{cope1866remarks41,
    author = "Cope, E. D",
    title = "Remarks on dinosaur remains from New Jersey",
    year = "1866",
    booktitle = "Academy of Natural Science, Philadelphia, Proceedings, p. 275-279",
    note = "talkorigins\_source = {true}; raw\_reference = {Cope, E. D., 1866, Remarks on dinosaur remains from New Jersey: Academy of Natural Science, Philadelphia, Proceedings, p. 275-279.}"
}

@misc{fox1866another57,
    author = "Fox, W",
    title = "Another new Wealden reptile",
    year = "1866",
    howpublished = "Geological Magazine, v. 3, p. 383",
    note = "talkorigins\_source = {true}; raw\_reference = {Fox, W., 1866, Another new Wealden reptile: Geological Magazine, v. 3, p. 383.}"
}

@misc{owen1876monograph97,
    author = "Owen, R",
    title = "Monograph of the fossil Reptilia of the Wealden Formations VII, Crocodilia and Dinosauria?",
    year = "1876",
    howpublished = "Palaeontogr. Soc., p. 2-7",
    note = "talkorigins\_source = {true}; raw\_reference = {Owen, R., 1876, Monograph of the fossil Reptilia of the Wealden Formations VII, Crocodilia and Dinosauria?: Palaeontogr. Soc., p. 2-7.}"
}

@article{marsh1877notice76,
    author = "Marsh, O. C",
    title = "Notice of new dinosaurian reptiles",
    year = "1877",
    journal = "American Journal of Science, v. 14, p. 514-516",
    note = "talkorigins\_source = {true}; raw\_reference = {Marsh, O. C., 1877, Notice of new dinosaurian reptiles: American Journal of Science, v. 14, p. 514-516.}"
}

@article{marsh1878notice77,
    author = "Marsh, O. C",
    title = "Notice of new dinosaurian reptiles",
    year = "1878",
    journal = "American Journal of Science, v. 15, p. 241-244",
    note = "talkorigins\_source = {true}; raw\_reference = {Marsh, O. C., 1878, Notice of new dinosaurian reptiles: American Journal of Science, v. 15, p. 241-244.}"
}

@article{marsh1879notice78,
    author = "Marsh, O. C",
    title = "Notice of new Jurassic reptiles",
    year = "1879",
    journal = "American Journal of Science, v. 21, p. 501-505",
    note = "talkorigins\_source = {true}; raw\_reference = {Marsh, O. C., 1879, Notice of new Jurassic reptiles: American Journal of Science, v. 21, p. 501-505.}"
}

Abstract Three classifications of the Dinosauria have been proposed, which differ from each other in the principles on which their authors proposed to make the divisions. First in time is Professor Cope’s classification (‘Philadelphia, Acad. Nat. Sci. Proc.,’ November 13th, 1866, and December 31st, 1867; ‘Amer. Phil. Soc. Trans.,’ vol. 14, Part I). He relied upon the characters of the tarsus and the ilium; and on their varied condition divided Dinosaurs into three orders named Orthopoda, Goniopoda, and Symphopoda. In the Orthopoda, the generic types associated are Scelidosaurus, Hylæosaurus, Iguanodon, and Hadrosaurus. And in this group the relations of the tibia and fibula are compared to those of modern Lizards, the proximal tarsals being distinct from each other and from the tibia. The ilium has a narrowed anterior prolongation.

@article{doi101098rspl18870117,
    author = "Seeley, H. G.",
    title = "I. On the classification of the fossil animals commonly named Dinosauria",
    year = "1888",
    journal = "Proceedings of the Royal Society of London",
    abstract = "Abstract Three classifications of the Dinosauria have been proposed, which differ from each other in the principles on which their authors proposed to make the divisions. First in time is Professor Cope’s classification (‘Philadelphia, Acad. Nat. Sci. Proc.,’ November 13th, 1866, and December 31st, 1867; ‘Amer. Phil. Soc. Trans.,’ vol. 14, Part I). He relied upon the characters of the tarsus and the ilium; and on their varied condition divided Dinosaurs into three orders named Orthopoda, Goniopoda, and Symphopoda. In the Orthopoda, the generic types associated are Scelidosaurus, Hylæosaurus, Iguanodon, and Hadrosaurus. And in this group the relations of the tibia and fibula are compared to those of modern Lizards, the proximal tarsals being distinct from each other and from the tibia. The ilium has a narrowed anterior prolongation.",
    url = "https://doi.org/10.1098/rspl.1887.0117",
    doi = "10.1098/rspl.1887.0117",
    openalex = "W1994653378"
}

@article{marsh1890description79,
    author = "Marsh, O. C",
    title = "Description of new dinosaurian reptiles",
    year = "1890",
    journal = "American Journal of Science, v. 39, p. 81-86",
    note = "talkorigins\_source = {true}; raw\_reference = {Marsh, O. C., 1890, Description of new dinosaurian reptiles: American Journal of Science, v. 39, p. 81-86.}"
}

@misc{lambe1902new70,
    author = "Lambe, L. M",
    title = "New genera and species from the Belly River Series (mid- Cretaceous)",
    year = "1902",
    howpublished = "Geological Survey of Canada, Contributions to Canadian Palaeontology, v. 3, p. 23-81",
    note = "talkorigins\_source = {true}; raw\_reference = {Lambe, L. M., 1902, New genera and species from the Belly River Series (mid- Cretaceous): Geological Survey of Canada, Contributions to Canadian Palaeontology, v. 3, p. 23-81.}"
}

@article{talbot1911podokesaurus122,
    author = "Talbot, M",
    title = "Podokesaurus holyokensis, a new dinosaur of the Connecticut Valley",
    year = "1911",
    journal = "American Journal of Science, v. 31, p. 469-479",
    note = "talkorigins\_source = {true}; raw\_reference = {Talbot, M., 1911, Podokesaurus holyokensis, a new dinosaur of the Connecticut Valley: American Journal of Science, v. 31, p. 469-479.}"
}

@article{shuler1917dinosaur117,
    author = "Shuler, E. W",
    title = "Dinosaur tracks in the Glen Rose limestone near Glen Rose, Texas",
    year = "1917",
    journal = "American Journal of Science, v. 44, p. 294-298",
    note = "talkorigins\_source = {true}; raw\_reference = {Shuler, E. W., 1917, Dinosaur tracks in the Glen Rose limestone near Glen Rose, Texas: American Journal of Science, v. 44, p. 294-298.}"
}

@misc{andrews1921on5,
    author = "Andrews, C. W",
    title = "On Some Remains of a Theropodous Dinosaur from the Lower Lias of Barrow-on-soar",
    year = "1921",
    howpublished = "Annual Magazine of Natural History, v. 8, no. 9, p. 570-576",
    note = "talkorigins\_source = {true}; raw\_reference = {Andrews, C. W., 1921, On Some Remains of a Theropodous Dinosaur from the Lower Lias of Barrow-on-soar: Annual Magazine of Natural History, v. 8, no. 9, p. 570-576.}"
}

@misc{osborn1921camarasaurus90,
    author = "Osborn, H. F. and Mook, C. C",
    title = "Camarasaurus, Amphicoelias, and other sauropods of Cope",
    year = "1921",
    howpublished = "American Museum of Natural History Memoirs, v. 3, p. 249-387; n.s",
    note = "talkorigins\_source = {true}; raw\_reference = {Osborn, H. F., and Mook, C. C., 1921, Camarasaurus, Amphicoelias, and other sauropods of Cope: American Museum of Natural History Memoirs, v. 3, p. 249-387; n.s.}"
}

@techreport{matthew1922the81,
    author = "Matthew, W. D. and Brown, B",
    title = "The family Deinodontidae with a notice of a new genus from the Cretaceous of Alberta",
    year = "1922",
    howpublished = "Bulletin of the American Museum of Natural History, v. 46, p. 367-385",
    note = "talkorigins\_source = {true}; raw\_reference = {Matthew, W. D., and Brown, B., 1922, The family Deinodontidae with a notice of a new genus from the Cretaceous of Alberta: Bulletin of the American Museum of Natural History, v. 46, p. 367-385.}"
}

@book{parks1933new98,
    author = "Parks, W. A",
    title = "New species of dinosaurs and turtles from the Upper Cretaceous Formations of Alberta",
    year = "1933",
    publisher = "University of Toronto Studies, Geological Series, v. 34, p. 1-19",
    note = "talkorigins\_source = {true}; raw\_reference = {Parks, W. A., 1933, New species of dinosaurs and turtles from the Upper Cretaceous Formations of Alberta: University of Toronto Studies, Geological Series, v. 34, p. 1-19.}"
}

@misc{stromer1934ergebnisse120,
    author = "Stromer, E",
    title = "Ergebnisse der forschungsreisen Prof. E. Stromers in den Westen Agyptens, Dinosauria",
    year = "1934",
    howpublished = "Abh. Bayer. Akad. Wissen.:Math.-natur. Abt., v. 22, p. 1-79",
    note = "talkorigins\_source = {true}; raw\_reference = {Stromer, E., 1934, Ergebnisse der forschungsreisen Prof. E. Stromers in den Westen Agyptens, Dinosauria: Abh. Bayer. Akad. Wissen.:Math.-natur. Abt., v. 22, p. 1-79.}"
}

@misc{ray1941big102,
    author = "Ray, G. E",
    title = "Big for his day",
    year = "1941",
    howpublished = "Natural History Magazine, v. 48, p. 36-39",
    note = "talkorigins\_source = {true}; raw\_reference = {Ray, G. E., 1941, Big for his day: Natural History Magazine, v. 48, p. 36-39.}"
}

@misc{colbert1948evolution33,
    author = "Colbert, E. H",
    title = "Evolution of the horned dinosaurs",
    year = "1948",
    howpublished = "Evolution, v. 2, p. 145-163",
    note = "talkorigins\_source = {true}; raw\_reference = {Colbert, E. H., 1948, Evolution of the horned dinosaurs: Evolution, v. 2, p. 145-163.}"
}

@misc{colbert1949evolutionary34,
    author = "Colbert, E. H",
    title = "Evolutionary growth rates in the dinosaurs",
    year = "1949",
    howpublished = "Scientific Monthly, v. 69, p. 71",
    note = "talkorigins\_source = {true}; raw\_reference = {Colbert, E. H., 1949, Evolutionary growth rates in the dinosaurs: Scientific Monthly, v. 69, p. 71.}"
}

@article{openalexw2259112626,
    author = "Enlow, Donald H.",
    title = "A comparative histological study of fossil and recent bone tissues",
    year = "1955",
    journal = "OakTrust (Texas A\&M University Libraries)",
    openalex = "W2259112626"
}

@misc{colbert1962the35,
    author = "Colbert, E. H",
    title = "The weight of dinosaurs",
    year = "1962",
    howpublished = "American Museum of Natural History Novitates, v. 2076, p. 1-16",
    note = "talkorigins\_source = {true}; raw\_reference = {Colbert, E. H., 1962, The weight of dinosaurs: American Museum of Natural History Novitates, v. 2076, p. 1-16.}"
}

@misc{reig1963la104,
    author = "Reig, O. A",
    title = {La presencia de dinosaurios en los "Estratos de Ischigualastro" (Mesotriasico Superior) de las provincias de San Juan y la Rioja},
    year = "1963",
    howpublished = "Ameghiniana, v. 3, p. 1-20",
    note = {talkorigins\_source = {true}; raw\_reference = {Reig, O. A., 1963, La presencia de dinosaurios en los "Estratos de Ischigualastro" (Mesotriasico Superior) de las provincias de San Juan y la Rioja: Ameghiniana, v. 3, p. 1-20.}}
}

@misc{colbert1965the36,
    author = "Colbert, E. H",
    title = "The Age of Reptiles",
    year = "1965",
    howpublished = "New York, Norton, 228 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Colbert, E. H., 1965, The Age of Reptiles: New York, Norton, 228 p.}"
}

@article{rozhdestvensky1965growth107,
    author = "Rozhdestvensky, A. K",
    title = "Growth changes in Asian dinosaurs and some problems of their taxonomy",
    year = "1965",
    journal = "Palaeontological Journal, p. 95-109",
    note = "talkorigins\_source = {true}; raw\_reference = {Rozhdestvensky, A. K., 1965, Growth changes in Asian dinosaurs and some problems of their taxonomy: Palaeontological Journal, p. 95-109.}"
}

@misc{colbert1966men37,
    author = "Colbert, E. H",
    title = "Men and Dinosaurs",
    year = "1966",
    howpublished = "The Search in Field and Laboratory: New York, E.P. Dutton and Co., Inc",
    note = "talkorigins\_source = {true}; raw\_reference = {Colbert, E. H., 1966, Men and Dinosaurs: The Search in Field and Laboratory: New York, E.P. Dutton and Co., Inc.}"
}

@misc{bakker1968the7,
    author = "Bakker, R. T",
    title = "The superiority of dinosaurs",
    year = "1968",
    howpublished = "Discovery, v. 3, p. 11-22",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., 1968, The superiority of dinosaurs: Discovery, v. 3, p. 11-22.}"
}

@misc{camp1968the30,
    author = "Camp, L. S. de and Camp, L. S. de",
    title = "The Day of the Dinosaur",
    year = "1968",
    howpublished = "New York, Doubleday",
    note = "talkorigins\_source = {true}; raw\_reference = {Camp, L. S. de, and Camp, L. S. de, 1968, The Day of the Dinosaur: New York, Doubleday.}"
}

@misc{colbert1968men38,
    author = "Colbert, E. H",
    title = "Men and Dinosaurs",
    year = "1968",
    howpublished = "The Search in Field and Laboratory: New York, E.P. Dutton and Co., 283 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Colbert, E. H., 1968, Men and Dinosaurs: The Search in Field and Laboratory: New York, E.P. Dutton and Co., 283 p.}"
}

@misc{colbert1969the39,
    author = "Colbert, E. H. and Russell, D. A",
    title = "The small dinosaur Dromaeosaurus",
    year = "1969",
    howpublished = "American Museum of Natural History Novitates, v. 2380, p. 1-49",
    note = "talkorigins\_source = {true}; raw\_reference = {Colbert, E. H., and Russell, D. A., 1969, The small dinosaur Dromaeosaurus: American Museum of Natural History Novitates, v. 2380, p. 1-49.}"
}

@article{halstead1970scrotum60,
    author = "Halstead, L. B",
    title = "Scrotum humanum Brooks 1763--the first named dinosaur",
    year = "1970",
    journal = "Journal of Insignificant Research, v. 5, p. 14-15",
    note = "talkorigins\_source = {true}; raw\_reference = {Halstead, L. B., 1970, Scrotum humanum Brooks 1763--the first named dinosaur: Journal of Insignificant Research, v. 5, p. 14-15.}"
}

@misc{swinton1970the121,
    author = "Swinton, W. G",
    title = "The Dinosaurs",
    year = "1970",
    howpublished = "London, George Allen and Unwin, Ltd",
    note = "talkorigins\_source = {true}; raw\_reference = {Swinton, W. G., 1970, The Dinosaurs: London, George Allen and Unwin, Ltd.}"
}

@misc{bakker1971dinosaur9,
    author = "Bakker, R. T",
    title = "Dinosaur physiology and the origin of mammals",
    year = "1971",
    howpublished = "Evolution, v. 25, p. 636-658",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., 1971, Dinosaur physiology and the origin of mammals: Evolution, v. 25, p. 636-658.}"
}

@misc{bakker1971ecology8,
    author = "Bakker, R. T",
    title = "Ecology of the brontosaurs",
    year = "1971",
    howpublished = "Nature, v. 229, p. 172-174",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., 1971, Ecology of the brontosaurs: Nature, v. 229, p. 172-174.}"
}

@article{russell1971the109,
    author = "Russell, D. A",
    title = "The disappearance of the dinosaurs",
    year = "1971",
    journal = "Canadian Geographic Journal, v. 83, p. 204-215",
    note = "talkorigins\_source = {true}; raw\_reference = {Russell, D. A., 1971, The disappearance of the dinosaurs: Canadian Geographic Journal, v. 83, p. 204-215.}"
}

@misc{welles1971dinosaur124,
    author = "Welles, S. P",
    title = "Dinosaur footprints from the Kayenta Formation of northern Arizona",
    year = "1971",
    howpublished = "Plateau, v. 44, p. 27-38",
    note = "talkorigins\_source = {true}; raw\_reference = {Welles, S. P., 1971, Dinosaur footprints from the Kayenta Formation of northern Arizona: Plateau, v. 44, p. 27-38.}"
}

@misc{ostrom1972dinosaur91,
    author = "Ostrom, J. H",
    title = "Dinosaur, in McGraw-Hill Yearbook, Science and Technology",
    year = "1972",
    howpublished = "New York, McGraw-Hill, p. 176-179",
    note = "talkorigins\_source = {true}; raw\_reference = {Ostrom, J. H., 1972, Dinosaur, in McGraw-Hill Yearbook, Science and Technology: New York, McGraw-Hill, p. 176-179.}"
}

@misc{ostrom1972were92,
    author = "Ostrom, J. H",
    title = "Were some dinosaurs gregarious?",
    year = "1972",
    howpublished = "Palaeogeography, Palaeoclimatology, Palaeoecology, v. 11, p. 287-301",
    note = "talkorigins\_source = {true}; raw\_reference = {Ostrom, J. H., 1972, Were some dinosaurs gregarious?: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 11, p. 287-301.}"
}

@misc{dong1973dinosaurs47,
    author = "Dong, Z",
    title = "Dinosaurs from Wuerho",
    year = "1973",
    howpublished = "Memoirs of the Institute of Vertebrate Paelontology and Paleoanthropology, Academy Sinica, v. 11, p. 45-52; In Chinese",
    note = "talkorigins\_source = {true}; raw\_reference = {Dong, Z., 1973, Dinosaurs from Wuerho: Memoirs of the Institute of Vertebrate Paelontology and Paleoanthropology, Academy Sinica, v. 11, p. 45-52; In Chinese.}"
}

@phdthesis{molnar1973the84,
    author = "Molnar, R. E",
    title = "The cranial morphology and mechanics of Tyrannosaurus rex (Reptilia",
    year = "1973",
    publisher = "Saurischia) [PhD dissert.]: University of California at Los Angeles",
    note = "talkorigins\_source = {true}; raw\_reference = {Molnar, R. E., 1973, The cranial morphology and mechanics of Tyrannosaurus rex (Reptilia: Saurischia) [PhD dissert.]: University of California at Los Angeles.}"
}

@article{russell1973the110,
    author = "Russell, D. A",
    title = "The environments of Canadian dinosaurs",
    year = "1973",
    journal = "Canadian Geographic Journal, v. 87, p. 4-11",
    note = "talkorigins\_source = {true}; raw\_reference = {Russell, D. A., 1973, The environments of Canadian dinosaurs: Canadian Geographic Journal, v. 87, p. 4-11.}"
}

@misc{spotila1973a119,
    author = "Spotila, J. R. et al",
    title = "A mathematical model for body temperatures of large reptiles",
    year = "1973",
    howpublished = "Implications for dinosaur ecology: American Naturalist, v. 107, p. 391-404",
    note = "talkorigins\_source = {true}; raw\_reference = {Spotila, J. R. et al., 1973, A mathematical model for body temperatures of large reptiles: Implications for dinosaur ecology: American Naturalist, v. 107, p. 391-404.}"
}

@misc{bakker1974dinosaur14,
    author = "Bakker, R. T. and Galton, P. M",
    title = "Dinosaur monophyly and a new class of vertebrates",
    year = "1974",
    howpublished = "Nature, v. 248, p. 168-172",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., and Galton, P. M., 1974, Dinosaur monophyly and a new class of vertebrates: Nature, v. 248, p. 168-172.}"
}

@misc{barsbold1974saurornithoididae15,
    author = "Barsbold, R",
    title = "Saurornithoididae, a new family of small theropod dinosaurs from Central Asia and North America",
    year = "1974",
    howpublished = "Palaeont. Polonica, v. 30, p. 5-22",
    note = "talkorigins\_source = {true}; raw\_reference = {Barsbold, R., 1974, Saurornithoididae, a new family of small theropod dinosaurs from Central Asia and North America: Palaeont. Polonica, v. 30, p. 5-22.}"
}

@misc{galton1974iliosuchus58,
    author = "Galton, P. M",
    title = "Iliosuchus, a Jurassic dinosaur from Oxfordshire and Utah",
    year = "1974",
    howpublished = "Palaeontology, v. 19, p. 587-589",
    note = "talkorigins\_source = {true}; raw\_reference = {Galton, P. M., 1974, Iliosuchus, a Jurassic dinosaur from Oxfordshire and Utah: Palaeontology, v. 19, p. 587-589.}"
}

@article{molnar1974a85,
    author = "Molnar, R. E",
    title = "A distinctive theropod dinosaur from the Upper Cretaceous of Baja California",
    year = "1974",
    journal = "Journal of Paleontology, v. 48, p. 1009-1017",
    note = "talkorigins\_source = {true}; raw\_reference = {Molnar, R. E., 1974, A distinctive theropod dinosaur from the Upper Cretaceous of Baja California: Journal of Paleontology, v. 48, p. 1009-1017.}"
}

@article{rozhdestvensky1974a108,
    author = "Rozhdestvensky, A. K",
    title = "A history of the dinosaur fauna from Asia and other continents and some problems of Paleogeography",
    year = "1974",
    journal = "Joint Soviet-Mongolian Palaeontological Expedition Transactions, v. 1, p. 107-131; In Russian",
    note = "talkorigins\_source = {true}; raw\_reference = {Rozhdestvensky, A. K., 1974, A history of the dinosaur fauna from Asia and other continents and some problems of Paleogeography: Joint Soviet-Mongolian Palaeontological Expedition Transactions, v. 1, p. 107-131; In Russian.}"
}

@misc{bakker1975dinosaur10,
    author = "Bakker, R. T",
    title = "Dinosaur Renaissance",
    year = "1975",
    howpublished = "Scientific American, v. 232, p. 58-78",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., 1975, Dinosaur Renaissance: Scientific American, v. 232, p. 58-78.}"
}

@misc{alexander1976estimates2,
    author = "Alexander, R. M",
    title = "Estimates of speeds of dinosaurs",
    year = "1976",
    howpublished = "Nature, v. 261, p. 129-130",
    note = "talkorigins\_source = {true}; raw\_reference = {Alexander, R. M., 1976, Estimates of speeds of dinosaurs: Nature, v. 261, p. 129-130.}"
}

@misc{barsbold1976a16,
    author = "Barsbold, R",
    title = "A new Late Cretaceous family of small theropods (Oviraptoridae, n. fam.) in Mongolia",
    year = "1976",
    howpublished = "Doklady Akad. Nauk. SSSR, v. 226, p. 221-223",
    note = "talkorigins\_source = {true}; raw\_reference = {Barsbold, R., 1976, A new Late Cretaceous family of small theropods (Oviraptoridae, n. fam.) in Mongolia: Doklady Akad. Nauk. SSSR, v. 226, p. 221-223.}"
}

@incollection{charig1976dinosaur31,
    author = "Charig, A. J",
    editor = "Bellairs, A. and Cox, C. B.",
    title = "Dinosaur Monophyly and a New Class of Vertebrates: A Critical Review",
    year = "1976",
    booktitle = "Morphology and Biology of the Reptiles, 3 of Linnean Society Symposia Series",
    publisher = "New York, Academic Press, p. 65-104",
    note = "talkorigins\_source = {true}; raw\_reference = {Charig, A. J., 1976, Dinosaur Monophyly and a New Class of Vertebrates: A Critical Review, in Bellairs, A., and Cox, C. B., eds., Morphology and Biology of the Reptiles, 3 of Linnean Society Symposia Series: New York, Academic Press, p. 65-104.}"
}

@book{desmond1976the44,
    author = "Desmond, A. J",
    title = "The Hot-Blooded Dinosaurs",
    year = "1976",
    publisher = "New York, The Dial Press",
    note = "talkorigins\_source = {true}; raw\_reference = {Desmond, A. J., 1976, The Hot-Blooded Dinosaurs: New York, The Dial Press.}"
}

@book{ratkevich1976dinosaurs101,
    author = "Ratkevich, R. P",
    title = "Dinosaurs of the Southwest",
    year = "1976",
    publisher = "Albuquerque, University of New Mexico Press",
    note = "talkorigins\_source = {true}; raw\_reference = {Ratkevich, R. P., 1976, Dinosaurs of the Southwest: Albuquerque, University of New Mexico Press.}"
}

@book{seymour1976dinosaurs116,
    author = "Seymour, R. S",
    title = "Dinosaurs, endothermy and blood pressure",
    year = "1976",
    publisher = "Nature, v. 262, p. 207-208",
    note = "talkorigins\_source = {true}; raw\_reference = {Seymour, R. S., 1976, Dinosaurs, endothermy and blood pressure: Nature, v. 262, p. 207-208.}"
}

@article{hopson1977relative64,
    author = "Hopson, J. A",
    title = "Relative brain size and behavior in archosaurian reptiles",
    year = "1977",
    journal = "Annual Review of Ecology and Systematics, v. 8, p. 429-448",
    note = "talkorigins\_source = {true}; raw\_reference = {Hopson, J. A., 1977, Relative brain size and behavior in archosaurian reptiles: Annual Review of Ecology and Systematics, v. 8, p. 429-448.}"
}

@misc{russell1977a111,
    author = "Russell, D. A",
    title = "A Vanished World",
    year = "1977",
    howpublished = "The Dinosaurs of Western Canada: Ottawa, National Museums of Canada",
    note = "talkorigins\_source = {true}; raw\_reference = {Russell, D. A., 1977, A Vanished World: The Dinosaurs of Western Canada: Ottawa, National Museums of Canada.}"
}

@article{coombs1978theoretical40,
    author = "Coombs, W. P",
    title = "Theoretical aspects of cursorial adaptations in dinosaurs",
    year = "1978",
    journal = "Quarterly Review of Biology, v. 53, p. 393-418",
    note = "talkorigins\_source = {true}; raw\_reference = {Coombs, W. P., 1978, Theoretical aspects of cursorial adaptations in dinosaurs: Quarterly Review of Biology, v. 53, p. 393-418.}"
}

@misc{marx1978warmblooded80,
    author = "Marx, J. L",
    title = "Warm-blooded dinosaurs",
    year = "1978",
    howpublished = "Evidence pro and con: Science, v. 199, p. 1424-1426",
    note = "talkorigins\_source = {true}; raw\_reference = {Marx, J. L., 1978, Warm-blooded dinosaurs: Evidence pro and con: Science, v. 199, p. 1424-1426.}"
}

@misc{ostrom1978the93,
    author = "Ostrom, J. H",
    title = "The osteology of Compsognathus longipes Wagner",
    year = "1978",
    howpublished = "Zitteliana, v. 4, p. 73-118",
    note = "talkorigins\_source = {true}; raw\_reference = {Ostrom, J. H., 1978, The osteology of Compsognathus longipes Wagner: Zitteliana, v. 4, p. 73-118.}"
}

@misc{barsbold1979opisthopubic17,
    author = "Barsbold, R",
    title = "Opisthopubic pelvis in the saurischian dinosaurs",
    year = "1979",
    howpublished = "Nature, v. 279, p. 792-793",
    note = "talkorigins\_source = {true}; raw\_reference = {Barsbold, R., 1979, Opisthopubic pelvis in the saurischian dinosaurs: Nature, v. 279, p. 792-793.}"
}

@misc{bonaparte1979dinosaurs27,
    author = "Bonaparte, J. F",
    title = "Dinosaurs, a Jurassic assemblage from Patagonia",
    year = "1979",
    howpublished = "Science, v. 205, p. 1377-1379",
    note = "talkorigins\_source = {true}; raw\_reference = {Bonaparte, J. F., 1979, Dinosaurs, a Jurassic assemblage from Patagonia: Science, v. 205, p. 1377-1379.}"
}

@misc{johnston1979growth69,
    author = "Johnston, P. A",
    title = "Growth rings in dinosaur teeth",
    year = "1979",
    howpublished = "Nature, v. 278, p. 635- 636",
    note = "talkorigins\_source = {true}; raw\_reference = {Johnston, P. A., 1979, Growth rings in dinosaur teeth: Nature, v. 278, p. 635- 636.}"
}

@article{russell1979the112,
    author = "Russell, D. A",
    title = "The enigma of the extinction of the dinosaurs",
    year = "1979",
    journal = "Annual Review of Earth and Planetary Sciences, v. 7, p. 163-182",
    note = "talkorigins\_source = {true}; raw\_reference = {Russell, D. A., 1979, The enigma of the extinction of the dinosaurs: Annual Review of Earth and Planetary Sciences, v. 7, p. 163-182.}"
}

@incollection{bakker1980dinosaur11,
    author = "Bakker, R. T",
    editor = "Thomas, D. K. and Olson, E. C.",
    title = "Dinosaur heresy-dinosaur renaissance: Why we need endothermic archosaurs for a comprehensive theory of bioenergetic evolution",
    year = "1980",
    booktitle = "A Cold Look at the Warm Blooded Dinosaurs",
    publisher = "Washington, D.C., American Association for the Advancement of Science, p. 351-462",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., 1980, Dinosaur heresy-dinosaur renaissance: Why we need endothermic archosaurs for a comprehensive theory of bioenergetic evolution, in Thomas, D. K., and Olson, E. C., eds., A Cold Look at the Warm Blooded Dinosaurs: Washington, D.C., American Association for the Advancement of Science, p. 351-462.}"
}

@misc{beland1980dinosaur24,
    author = "Beland, P. and Russell, D. A",
    title = "Dinosaur Metabolism and Predator/Prey Ratios in the Fossil Record, in Thomas, D. K., and Olson, E. C., eds., A Cold Look at the Warm Blooded Dinosaurs",
    year = "1980",
    howpublished = "Washington, D.C., American Association for the Advancement of Science, p. 82-105",
    note = "talkorigins\_source = {true}; raw\_reference = {Beland, P., and Russell, D. A., 1980, Dinosaur Metabolism and Predator/Prey Ratios in the Fossil Record, in Thomas, D. K., and Olson, E. C., eds., A Cold Look at the Warm Blooded Dinosaurs: Washington, D.C., American Association for the Advancement of Science, p. 82-105.}"
}

@misc{dodson1980taphonomy46,
    author = "Dodson, P. and Behrensmeyer, A. K. and Bakker, R. T. and McIntosh, J. S",
    title = "Taphonomy and paleoecology of the dinosaur beds of the Jurassic Morrison Formation",
    year = "1980",
    howpublished = "Paleobiology, v. 6, p. 208-232",
    note = "talkorigins\_source = {true}; raw\_reference = {Dodson, P., Behrensmeyer, A. K., Bakker, R. T., and McIntosh, J. S., 1980, Taphonomy and paleoecology of the dinosaur beds of the Jurassic Morrison Formation: Paleobiology, v. 6, p. 208-232.}"
}

@incollection{hopson1980relative65,
    author = "Hopson, J. A",
    editor = "Thomas, D. K. and Olson, E. C.",
    title = "Relative Brainsize in Dinosaurs: Implications for Dinosaur Endothermy",
    year = "1980",
    booktitle = "A Cold Look at the Warm Blooded Dinosaurs",
    publisher = "Washington, D.C., American Association for the Advancement of Science, p. 287-310",
    note = "talkorigins\_source = {true}; raw\_reference = {Hopson, J. A., 1980, Relative Brainsize in Dinosaurs: Implications for Dinosaur Endothermy, in Thomas, D. K., and Olson, E. C., eds., A Cold Look at the Warm Blooded Dinosaurs: Washington, D.C., American Association for the Advancement of Science, p. 287-310.}"
}

@incollection{hotton1980an67,
    author = "Hotton, N",
    editor = "Thomas, D. K. and Olson, E. C.",
    title = "An Alternative to Dinosaur Endothermy: The Happy Wanderers",
    year = "1980",
    booktitle = "A Cold Look at the Warm Blooded Dinosaurs",
    publisher = "Washington, D.C., American Association for the Advancement of Science, p. 311-350",
    note = "talkorigins\_source = {true}; raw\_reference = {Hotton, N., 1980, An Alternative to Dinosaur Endothermy: The Happy Wanderers, in Thomas, D. K., and Olson, E. C., eds., A Cold Look at the Warm Blooded Dinosaurs: Washington, D.C., American Association for the Advancement of Science, p. 311-350.}"
}

@misc{molnar1980a86,
    author = "Molnar, R. E. and Pledge, N. S",
    title = "A new theropod dinosaur from South Australia",
    year = "1980",
    howpublished = "Alcheringa, v. 4, p. 281-287",
    note = "talkorigins\_source = {true}; raw\_reference = {Molnar, R. E., and Pledge, N. S., 1980, A new theropod dinosaur from South Australia: Alcheringa, v. 4, p. 281-287.}"
}

@incollection{ricqles1980tissue105,
    author = "Ricqles, A. R",
    editor = "Thomas, D. K. and Olson, E. C.",
    title = "Tissue Structures of Dinosaur Bones: Functional Significance and Possible Relation to Dinosaur Physiology",
    year = "1980",
    booktitle = "A Cold Look at the Warm Blooded Dinosaurs",
    publisher = "Washington, D.C., American Association for the Advancement of Science, p. 103-140",
    note = "talkorigins\_source = {true}; raw\_reference = {Ricqles, A. R., 1980, Tissue Structures of Dinosaur Bones: Functional Significance and Possible Relation to Dinosaur Physiology, in Thomas, D. K., and Olson, E. C., eds., A Cold Look at the Warm Blooded Dinosaurs: Washington, D.C., American Association for the Advancement of Science, p. 103-140.}"
}

@misc{russell1980paleocology114,
    author = "Russell, D. A. and Beland, P. and McIntosh, J. S",
    title = "Paleocology of the dinosaurs of Tendaguru (Tanzania)",
    year = "1980",
    howpublished = "Mem. Soc. Geol. Fr., v. 59, no. 139, p. 169-175",
    note = "talkorigins\_source = {true}; raw\_reference = {Russell, D. A., Beland, P., and McIntosh, J. S., 1980, Paleocology of the dinosaurs of Tendaguru (Tanzania): Mem. Soc. Geol. Fr., v. 59, no. 139, p. 169-175.}"
}

@article{barsbold1981toothless18,
    author = "Barsbold, R",
    title = "Toothless carnivorous dinosaurs of Mongolia",
    year = "1981",
    journal = "Joint Soviet-Mongolian Palaeontological Expedition Transactions, v. 15, p. 28-39; In Russian",
    note = "talkorigins\_source = {true}; raw\_reference = {Barsbold, R., 1981, Toothless carnivorous dinosaurs of Mongolia: Joint Soviet-Mongolian Palaeontological Expedition Transactions, v. 15, p. 28-39; In Russian.}"
}

Data on numbers of marine families within 91 metazoan classes known from the Phanerozoic fossil record are analyzed. The distribution of the 2800 fossil families among the classes is very uneven, with most belonging to a small minority of classes. Similarly, the stratigraphic distribution of the classes is very uneven, with most first appearing early in the Paleozoic and with many of the smaller classes becoming extinct before the end of that era. However, despite this unevenness, a Q -mode factor analysis indicates that the structure of these data is rather simple. Only three factors are needed to account for more than 90% of the data. These factors are interpreted as reflecting the three great “evolutionary faunas” of the Phanerozoic marine record: a trilobite-dominated Cambrian fauna, a brachiopod-dominated later Paleozoic fauna, and a mollusc-dominated Mesozoic-Cenozoic, or “modern,” fauna. Lesser factors relate to slow taxonomic turnover within the major faunas through time and to unique aspects of particular taxa and times. Each of the three major faunas seems to have its own characteristic diversity so that its expansion or contraction appears as being intimately associated with a particular phase in the history of total marine diversity. The Cambrian fauna expands rapidly during the Early Cambrian radiations and maintains dominance during the Middle to Late Cambrian “equilibrium.” The Paleozoic fauna then ascends to dominance during the Ordovician radiations, which increase diversity dramatically; this new fauna then maintains dominance throughout the long interval of apparent equilibrium that lasts until the end of the Paleozoic Era. The modern fauna, which slowly increases in importance during the Paleozoic Era, quickly rises to dominance with the Late Permian extinctions and maintains that status during the general rise in diversity to the apparent maximum in the Neogene. The increase in diversity associated with the expansion of each new fauna appears to coincide with an approximately exponential decline of the previously dominant fauna, suggesting possible displacement of each evolutionary fauna by its successor.

@article{doi101017s0094837300003778,
    author = "Sepkoski, J. John",
    title = "A factor analytic description of the Phanerozoic marine fossil record",
    year = "1981",
    journal = "Paleobiology",
    abstract = "Data on numbers of marine families within 91 metazoan classes known from the Phanerozoic fossil record are analyzed. The distribution of the 2800 fossil families among the classes is very uneven, with most belonging to a small minority of classes. Similarly, the stratigraphic distribution of the classes is very uneven, with most first appearing early in the Paleozoic and with many of the smaller classes becoming extinct before the end of that era. However, despite this unevenness, a Q -mode factor analysis indicates that the structure of these data is rather simple. Only three factors are needed to account for more than 90\% of the data. These factors are interpreted as reflecting the three great “evolutionary faunas” of the Phanerozoic marine record: a trilobite-dominated Cambrian fauna, a brachiopod-dominated later Paleozoic fauna, and a mollusc-dominated Mesozoic-Cenozoic, or “modern,” fauna. Lesser factors relate to slow taxonomic turnover within the major faunas through time and to unique aspects of particular taxa and times. Each of the three major faunas seems to have its own characteristic diversity so that its expansion or contraction appears as being intimately associated with a particular phase in the history of total marine diversity. The Cambrian fauna expands rapidly during the Early Cambrian radiations and maintains dominance during the Middle to Late Cambrian “equilibrium.” The Paleozoic fauna then ascends to dominance during the Ordovician radiations, which increase diversity dramatically; this new fauna then maintains dominance throughout the long interval of apparent equilibrium that lasts until the end of the Paleozoic Era. The modern fauna, which slowly increases in importance during the Paleozoic Era, quickly rises to dominance with the Late Permian extinctions and maintains that status during the general rise in diversity to the apparent maximum in the Neogene. The increase in diversity associated with the expansion of each new fauna appears to coincide with an approximately exponential decline of the previously dominant fauna, suggesting possible displacement of each evolutionary fauna by its successor.",
    url = "https://doi.org/10.1017/s0094837300003778",
    doi = "10.1017/s0094837300003778",
    openalex = "W2505144080",
    references = "doi10100797814613088367, doi1010160012825272900724, doi101017s0094837300004917, doi101017s009483730000508x, doi101017s0094837300005236, doi101017s0094837300005352, doi101017s0094837300005649, doi101017s0094837300005972, doi101017s0094837300012549, doi101126science17740541065, doi101126science2064415217, doi101130spe89p63, doi1023071483846, doi1023071796560, doi1023072405671, doi1023072412725, doi1023072412728, doi1023072806339, doi107312simp93764, openalexw1504049102, openalexw645218623"
}

@misc{farlow1981estimates53,
    author = "Farlow, J. O",
    title = "Estimates of dinosaur speeds from a new trackway site in Texas",
    year = "1981",
    howpublished = "Nature, v. 294, p. 747-748",
    note = "talkorigins\_source = {true}; raw\_reference = {Farlow, J. O., 1981, Estimates of dinosaur speeds from a new trackway site in Texas: Nature, v. 294, p. 747-748.}"
}

@book{halstead1981dinosaurs61,
    author = "Halstead, L. B. and Halstead, J",
    title = "Dinosaurs",
    year = "1981",
    publisher = "Dorset, Blanford Press",
    note = "talkorigins\_source = {true}; raw\_reference = {Halstead, L. B., and Halstead, J., 1981, Dinosaurs: Dorset, Blanford Press.}"
}

@book{leipzig1981myological73,
    author = "Leipzig, M. R",
    title = "Myological and Osteological Comparisons of Three Large Extant Reptiles ( Caiman sp., Tegu sp., Heloderma suspectum) and Implications on Dinosaurian Locomotion [Vertebrate Paleontology dissert.]",
    year = "1981",
    publisher = "University of Wisconsin-Milwaukee, 99 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Leipzig, M. R., 1981, Myological and Osteological Comparisons of Three Large Extant Reptiles ( Caiman sp., Tegu sp., Heloderma suspectum) and Implications on Dinosaurian Locomotion [Vertebrate Paleontology dissert.]: University of Wisconsin-Milwaukee, 99 p.}"
}

@misc{edwords1982the51,
    author = "Edwords, F",
    title = "The dilemma of the horned dinosaurs",
    year = "1982",
    howpublished = "Creation/Evolution, v. 3, p. 1-11",
    note = "talkorigins\_source = {true}; raw\_reference = {Edwords, F., 1982, The dilemma of the horned dinosaurs: Creation/Evolution, v. 3, p. 1-11.}"
}

@book{glut1982the59,
    author = "Glut, D. F",
    title = "The New Dinosaur Dictionary",
    year = "1982",
    publisher = "Secaucus, New Jersey, Citadel Press",
    note = "talkorigins\_source = {true}; raw\_reference = {Glut, D. F., 1982, The New Dinosaur Dictionary: Secaucus, New Jersey, Citadel Press.}"
}

@misc{russell1982reconstruction115,
    author = "Russell, D. A. and Sequin, R",
    title = "Reconstruction of the small Cretaceous theropod Stenonychosaurus inequalis and a hypothetical dinosauroid",
    year = "1982",
    howpublished = "Syllogeous, v. 37, p. 1-43",
    note = "talkorigins\_source = {true}; raw\_reference = {Russell, D. A., and Sequin, R., 1982, Reconstruction of the small Cretaceous theropod Stenonychosaurus inequalis and a hypothetical dinosauroid: Syllogeous, v. 37, p. 1-43.}"
}

@article{barsbold1983carnivorous19,
    author = "Barsbold, R",
    title = "Carnivorous dinosaurs from the Cretaceous of Mongolia",
    year = "1983",
    journal = "Joint Soviet- Mongolian Palaeontological Expedition Transactions, v. 19, p. 1-120; In Russian",
    note = "talkorigins\_source = {true}; raw\_reference = {Barsbold, R., 1983, Carnivorous dinosaurs from the Cretaceous of Mongolia: Joint Soviet- Mongolian Palaeontological Expedition Transactions, v. 19, p. 1-120; In Russian.}"
}

@article{barsbold1983on20,
    author = "Barsbold, R",
    title = {On the "avian" features of the structure of carnivorous dinosaurs},
    year = "1983",
    journal = "Joint Soviet-Mongolian Palaeontological Expedition Transactions, v. 24, p. 96-103; In Russian",
    note = {talkorigins\_source = {true}; raw\_reference = {Barsbold, R., 1983, On the "avian" features of the structure of carnivorous dinosaurs: Joint Soviet-Mongolian Palaeontological Expedition Transactions, v. 24, p. 96-103; In Russian.}}
}

@article{benton1983dinosaur25,
    author = "Benton, M. J",
    title = "Dinosaur success in the Triassic",
    year = "1983",
    journal = "A noncompetitive ecological model: Quarterly Review of Biology, v. 58, p. 29-55",
    note = "talkorigins\_source = {true}; raw\_reference = {Benton, M. J., 1983, Dinosaur success in the Triassic: A noncompetitive ecological model: Quarterly Review of Biology, v. 58, p. 29-55.}"
}

@misc{dong1983the49,
    author = "Dong, Z. and Zhou, S. and Zhang, Y",
    title = "The dinosaurian remains from Sichuan Basin, China",
    year = "1983",
    howpublished = "Palaeontographica Sinica, v. 162, p. 1-147; In Chinese",
    note = "talkorigins\_source = {true}; raw\_reference = {Dong, Z., Zhou, S., and Zhang, Y., 1983, The dinosaurian remains from Sichuan Basin, China: Palaeontographica Sinica, v. 162, p. 1-147; In Chinese.}"
}

@misc{mcgowan1983the82,
    author = "McGowan, C",
    title = "The Successful Dragons",
    year = "1983",
    howpublished = "A Natural History of Extinct Reptiles: Toronto, Samuel-Stevens",
    note = "talkorigins\_source = {true}; raw\_reference = {McGowan, C., 1983, The Successful Dragons: A Natural History of Extinct Reptiles: Toronto, Samuel-Stevens.}"
}

@misc{mcgowen1983the83,
    author = "McGowen, C",
    title = "The Successful Dragons",
    year = "1983",
    howpublished = "Toronto, Samuel Stevens and Co",
    note = "talkorigins\_source = {true}; raw\_reference = {McGowen, C., 1983, The Successful Dragons: Toronto, Samuel Stevens and Co.}"
}

@article{barsbold1984the23,
    author = "Barsbold, R. and Perle, A",
    title = "The first record of a primitive ornithomimosaur from the Cretaceous of Mongolia",
    year = "1984",
    journal = "Palaeontological Journal, v. 2, p. 118-120",
    note = "talkorigins\_source = {true}; raw\_reference = {Barsbold, R., and Perle, A., 1984, The first record of a primitive ornithomimosaur from the Cretaceous of Mongolia: Palaeontological Journal, v. 2, p. 118-120.}"
}

@inproceedings{benton1984fossil26,
    author = "Benton, M. J",
    title = "Fossil Reptiles of the German Late Triassic and the Origin of the Dinosaurs, in Reif, W. E., and Westphal, F., eds., Third Symposium on Mesozoic Terrestrial Ecosystems",
    year = "1984",
    booktitle = "Tbingen, ATTEMPTO-Verlag, p. 13-18",
    note = "talkorigins\_source = {true}; raw\_reference = {Benton, M. J., 1984, Fossil Reptiles of the German Late Triassic and the Origin of the Dinosaurs, in Reif, W. E., and Westphal, F., eds., Third Symposium on Mesozoic Terrestrial Ecosystems: Tbingen, ATTEMPTO-Verlag, p. 13-18.}"
}

@misc{dong1984a48,
    author = "Dong, Z",
    title = "A new theropod dinosaur from the Middle Jurassic of Sichuan Basin",
    year = "1984",
    howpublished = "Vertebrate Palasiatica, v. XXII, p. 213-218; In Chinese",
    note = "talkorigins\_source = {true}; raw\_reference = {Dong, Z., 1984, A new theropod dinosaur from the Middle Jurassic of Sichuan Basin: Vertebrate Palasiatica, v. XXII, p. 213-218; In Chinese.}"
}

@misc{ham1984what62,
    author = "Ham, K",
    title = "What happened to the dinosaurs?",
    year = "1984",
    howpublished = "Ex Nihilo, v. 7, no. 2, p. 6-11",
    note = "talkorigins\_source = {true}; raw\_reference = {Ham, K., 1984, What happened to the dinosaurs?: Ex Nihilo, v. 7, no. 2, p. 6-11.}"
}

@misc{leonardi1984le75,
    author = "Leonardi, G",
    title = "Le impronte fossili di dinosauri, in Sulle orme dei Dinosauri",
    year = "1984",
    howpublished = "Paleont. Ricatore (C.N.P.Q.) del Brasile, p. 165-186",
    note = "talkorigins\_source = {true}; raw\_reference = {Leonardi, G., 1984, Le impronte fossili di dinosauri, in Sulle orme dei Dinosauri: Paleont. Ricatore (C.N.P.Q.) del Brasile, p. 165-186.}"
}

@inproceedings{reid1984the103,
    author = "Reid, R. E. H",
    title = "The histology of dinosaurian bone, and its possible bearing on dinosaur physiology",
    year = "1984",
    booktitle = "Symposium of the Zoological Society, London, v. 52, p. 629-663",
    note = "talkorigins\_source = {true}; raw\_reference = {Reid, R. E. H., 1984, The histology of dinosaurian bone, and its possible bearing on dinosaur physiology: Symposium of the Zoological Society, London, v. 52, p. 629-663.}"
}

@misc{russell1984the113,
    author = "Russell, D. A",
    title = "The gradual decline of the dinosaurs - fact or fallacy?",
    year = "1984",
    howpublished = "Nature, v. 307, p. 360-361",
    note = "talkorigins\_source = {true}; raw\_reference = {Russell, D. A., 1984, The gradual decline of the dinosaurs - fact or fallacy?: Nature, v. 307, p. 360-361.}"
}

@article{alexander1985mechanics3,
    author = "Alexander, R. M",
    title = "Mechanics of posture and gait of some large dinosaurs",
    year = "1985",
    journal = "Zoological Journal of the Linnean Society, v. 83, p. 1-25",
    note = "talkorigins\_source = {true}; raw\_reference = {Alexander, R. M., 1985, Mechanics of posture and gait of some large dinosaurs: Zoological Journal of the Linnean Society, v. 83, p. 1-25.}"
}

The mid‐shaft circumferences of the humerus and femur are closely related to body weight in living terrestrial vertebrates. Because these elements are frequently preserved in subfossil and fossil vertebrate skeletal materials, the relationship can be used to estimate body weight in extinct vertebrates. When the allometric equations are applied to the mid‐shaft circumferences of these elements in dinosaurs, the weights calculated for some giant sauropods (Brachiosaurus) are found to be lighter than previous estimates.

@article{doi101111j146979981985tb04915x,
    author = "Anderson, John F. and Hall-Martin, A.J. and Russell, Dale A.",
    title = "Long‐bone circumference and weight in mammals, birds and dinosaurs",
    year = "1985",
    journal = "Journal of Zoology",
    abstract = "The mid‐shaft circumferences of the humerus and femur are closely related to body weight in living terrestrial vertebrates. Because these elements are frequently preserved in subfossil and fossil vertebrate skeletal materials, the relationship can be used to estimate body weight in extinct vertebrates. When the allometric equations are applied to the mid‐shaft circumferences of these elements in dinosaurs, the weights calculated for some giant sauropods (Brachiosaurus) are found to be lighter than previous estimates.",
    url = "https://doi.org/10.1111/j.1469-7998.1985.tb04915.x",
    doi = "10.1111/j.1469-7998.1985.tb04915.x",
    openalex = "W2160621949",
    references = "bakker1972anatomical, crossref1976allosaurus, doi101017s0094837300004322, doi101038238081a0, doi101086410790, doi101111j136520281979tb00256x, doi101111j146979981979tb03940x, doi101111j146979981979tb03964x, doi101111j146979981983tb05785x, doi1023072987996, openalexw654491377"
}

@misc{dusheck1985arctic50,
    author = "Dusheck, J",
    title = "Arctic dinosaurs raise questions",
    year = "1985",
    howpublished = "Science News, v. 128, p. 135",
    note = "talkorigins\_source = {true}; raw\_reference = {Dusheck, J., 1985, Arctic dinosaurs raise questions: Science News, v. 128, p. 135.}"
}

@misc{jensen1985uncompahgre68,
    author = "Jensen, J. A",
    title = "Uncompahgre dinosaur fauna",
    year = "1985",
    howpublished = "a preliminary report: Great Basin Naturalist, v. 45, p. 710-720",
    note = "talkorigins\_source = {true}; raw\_reference = {Jensen, J. A., 1985, Uncompahgre dinosaur fauna: a preliminary report: Great Basin Naturalist, v. 45, p. 710-720.}"
}

@misc{norman1985the89,
    author = "Norman, D",
    title = "The Illustrated Encyclopedia of Dinosaurs",
    year = "1985",
    howpublished = "New York, Cresent Books",
    note = "talkorigins\_source = {true}; raw\_reference = {Norman, D., 1985, The Illustrated Encyclopedia of Dinosaurs: New York, Cresent Books.}"
}

@misc{wilford1985the125,
    author = "Wilford, J. N",
    title = "The Riddle of the Dinosaur",
    year = "1985",
    howpublished = "New York, Random House",
    note = "talkorigins\_source = {true}; raw\_reference = {Wilford, J. N., 1985, The Riddle of the Dinosaur: New York, Random House.}"
}

@misc{arcucci1986nuevos6,
    author = "Arcucci, A",
    title = "Nuevos materiales y reinterpretatcion de Lagerpeton chanarenis Romer (Thecodontia, Lagerpetonidae nov.)",
    year = "1986",
    howpublished = "Ameghiniana, v. 23, no. 3-4, p. 233-242",
    note = "talkorigins\_source = {true}; raw\_reference = {Arcucci, A., 1986, Nuevos materiales y reinterpretatcion de Lagerpeton chanarenis Romer (Thecodontia, Lagerpetonidae nov.): Ameghiniana, v. 23, no. 3-4, p. 233-242.}"
}

@misc{bakker1986the12,
    author = "Bakker, R. T",
    title = "The Dinosaur Heresies",
    year = "1986",
    howpublished = "New Theories Unlocking the Mystery of the Dinosaurs and Their Extinction: New York, William Morrow \& Company, Inc",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., 1986, The Dinosaur Heresies: New Theories Unlocking the Mystery of the Dinosaurs and Their Extinction: New York, William Morrow \& Company, Inc.}"
}

@article{barsbold1986carnivorous21,
    author = "Barsbold, R",
    title = "Carnivorous Dinosaurs",
    year = "1986",
    journal = "Oviraptors, in Collected Transactions of the Institute of Evolutionary Morphology of the USSR Academy of Science: Moscow, USSR Academy of Science, p. 210-223; In Russian",
    note = "talkorigins\_source = {true}; raw\_reference = {Barsbold, R., 1986, Carnivorous Dinosaurs: Oviraptors, in Collected Transactions of the Institute of Evolutionary Morphology of the USSR Academy of Science: Moscow, USSR Academy of Science, p. 210-223; In Russian.}"
}

@misc{bunney1986claws29,
    author = "Bunney, S",
    title = {Claws" makes its official debut},
    year = "1986",
    howpublished = "New Scientist, v. 112, p. 25",
    note = {talkorigins\_source = {true}; raw\_reference = {Bunney, S., 1986, "Claws" makes its official debut: New Scientist, v. 112, p. 25.}}
}

@misc{charig1986baryonyx32,
    author = "Charig, A. J. and Milner, A. J",
    title = "Baryonyx, a remarkable new theropod dinosaur",
    year = "1986",
    howpublished = "Nature, v. 324, p. 359-361",
    note = "talkorigins\_source = {true}; raw\_reference = {Charig, A. J., and Milner, A. J., 1986, Baryonyx, a remarkable new theropod dinosaur: Nature, v. 324, p. 359-361.}"
}

@misc{farlow1986in54,
    author = "Farlow, J. O",
    title = "In the footsteps of dinosaurs?",
    year = "1986",
    howpublished = "Nature, v. 323, p. 390",
    note = "talkorigins\_source = {true}; raw\_reference = {Farlow, J. O., 1986, In the footsteps of dinosaurs?: Nature, v. 323, p. 390.}"
}

@misc{hasegawa1986gobi63,
    author = "Hasegawa, Y",
    title = "Gobi Desert Dinosaurs Exhibit",
    year = "1986",
    howpublished = "Japan Cultural Association",
    note = "talkorigins\_source = {true}; raw\_reference = {Hasegawa, Y., 1986, Gobi Desert Dinosaurs Exhibit. Japan Cultural Association.}"
}

@book{ostrom1986social94,
    author = "Ostrom, J. H",
    title = "Social and Unsocial Behavior in Dinosaurs, in Evolution of Animal Behavior",
    year = "1986",
    publisher = "Oxford, Oxford University Press, p. 41-61",
    note = "talkorigins\_source = {true}; raw\_reference = {Ostrom, J. H., 1986, Social and Unsocial Behavior in Dinosaurs, in Evolution of Animal Behavior: Oxford, Oxford University Press, p. 41-61.}"
}

@misc{sloan1986gradual118,
    author = "Sloan, R. E. et al",
    title = "Gradual dinosaur extinction and simultaneous ungulate radiation in the Hell Creek Formation",
    year = "1986",
    howpublished = "Science, v. 232, p. 629-633",
    note = "talkorigins\_source = {true}; raw\_reference = {Sloan, R. E. et al., 1986, Gradual dinosaur extinction and simultaneous ungulate radiation in the Hell Creek Formation: Science, v. 232, p. 629-633.}"
}

@misc{weisburd1986oldest123,
    author = "Weisburd, S",
    title = "Oldest Bird and Longest Dinosaur",
    year = "1986",
    howpublished = "Science News, v. 130, p. 103",
    note = "talkorigins\_source = {true}; raw\_reference = {Weisburd, S., 1986, Oldest Bird and Longest Dinosaur: Science News, v. 130, p. 103.}"
}

@incollection{adams1987the1,
    author = "Adams, D",
    editor = "ch. 1-6 of Currie, P. J. and Koster, E.",
    title = "The bigger they are, the harder they fall: Implications of ischial curvature in ceratopsian dinosaurs",
    year = "1987",
    booktitle = "Fourth Symposium on Mesozoic Terrestrial Ecosystems",
    publisher = "Drumheller, Canada, Tyrrell Museum",
    note = "talkorigins\_source = {true}; raw\_reference = {Adams, D., 1987, The bigger they are, the harder they fall: Implications of ischial curvature in ceratopsian dinosaurs, in ch. 1-6 of Currie, P. J., and Koster, E., eds., Fourth Symposium on Mesozoic Terrestrial Ecosystems: Drumheller, Canada, Tyrrell Museum.}"
}

@misc{anderson1987chinese4,
    author = "Anderson, I",
    title = "Chinese Unearth a Dinosaurs' Graveyard",
    year = "1987",
    howpublished = "New Scientist, v. 116, p. 28-29",
    note = "talkorigins\_source = {true}; raw\_reference = {Anderson, I., 1987, Chinese Unearth a Dinosaurs' Graveyard: New Scientist, v. 116, p. 28-29.}"
}

@misc{bakker1987the13,
    author = "Bakker, R. T",
    title = "The return of the Dancing Dinosaurs, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, 1",
    year = "1987",
    howpublished = "Los Angeles, Natural History Museum of Los Angeles County, p. 38-69",
    note = "talkorigins\_source = {true}; raw\_reference = {Bakker, R. T., 1987, The return of the Dancing Dinosaurs, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, 1: Los Angeles, Natural History Museum of Los Angeles County, p. 38-69.}"
}

@misc{barsbold1987on22,
    author = "Barsbold, R. and Osmolska, H. and Kurzanov, S. M",
    title = "On a new troodontid (Dinosauria, Theropoda) from the Early Cretaceous of Mongolia",
    year = "1987",
    howpublished = "Acta Palaeontologica Polonica, v. 32, p. 121-132",
    note = "talkorigins\_source = {true}; raw\_reference = {Barsbold, R., Osmolska, H., and Kurzanov, S. M., 1987, On a new troodontid (Dinosauria, Theropoda) from the Early Cretaceous of Mongolia: Acta Palaeontologica Polonica, v. 32, p. 121-132.}"
}

@misc{currie1987new42,
    author = "Currie, P. J",
    title = "New Approaches to Studying Dinosaurs in Dinosaur Provincial Park, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, II",
    year = "1987",
    howpublished = "Los Angeles, Natural History Museum of Los Angeles County, p. 100-117",
    note = "talkorigins\_source = {true}; raw\_reference = {Currie, P. J., 1987, New Approaches to Studying Dinosaurs in Dinosaur Provincial Park, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, II: Los Angeles, Natural History Museum of Los Angeles County, p. 100-117.}"
}

@misc{czerkas1987dinosaurs43,
    author = "Czerkas, S. J. and Olson, E. C",
    title = "Dinosaurs Past and Present (2 Volumes)",
    year = "1987",
    howpublished = "Los Angeles, Natural History Museum of Los Angeles County",
    note = "talkorigins\_source = {true}; raw\_reference = {Czerkas, S. J., and Olson, E. C., 1987, Dinosaurs Past and Present (2 Volumes): Los Angeles, Natural History Museum of Los Angeles County.}"
}

@book{farlow1987a55,
    author = "Farlow, J. O",
    title = "A Guide to the Lower Cretaceous Dinosaur Footprints and Trackways of the Paluxy River Valley, Somervell County, Texas",
    year = "1987",
    publisher = "Waco, Texas, Baylor University Press",
    note = "talkorigins\_source = {true}; raw\_reference = {Farlow, J. O., 1987, A Guide to the Lower Cretaceous Dinosaur Footprints and Trackways of the Paluxy River Valley, Somervell County, Texas: Waco, Texas, Baylor University Press.}"
}

@incollection{leahy1987the71,
    author = "Leahy, G. D",
    editor = "Currie, P. J. and Koster, E.",
    title = "The Gradual Extinction of Dinosaurs: Fact of Artifact?",
    year = "1987",
    booktitle = "Fourth Symposium on Mesozoic Terrestrial Ecosystems",
    publisher = "Drumheller, Canada, Tyrrell Museum, p. 138-143",
    note = "talkorigins\_source = {true}; raw\_reference = {Leahy, G. D., 1987, The Gradual Extinction of Dinosaurs: Fact of Artifact?, in Currie, P. J., and Koster, E., eds., Fourth Symposium on Mesozoic Terrestrial Ecosystems: Drumheller, Canada, Tyrrell Museum, p. 138-143.}"
}

@misc{lehman1987late72,
    author = "Lehman, T. M",
    title = "Late Maastrichtian paleoenvironments and dinosaur biogeography in the western interior of North America",
    year = "1987",
    howpublished = "Palaeogeography, Palaeoclimatology, Palaeoecology, v. 60, p. 189-217",
    note = "talkorigins\_source = {true}; raw\_reference = {Lehman, T. M., 1987, Late Maastrichtian paleoenvironments and dinosaur biogeography in the western interior of North America: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 60, p. 189-217.}"
}

@misc{morell1987the87,
    author = "Morell, V",
    title = "The birth of a heresy",
    year = "1987",
    howpublished = "Discover, v. 8, p. 26-50",
    note = "talkorigins\_source = {true}; raw\_reference = {Morell, V., 1987, The birth of a heresy: Discover, v. 8, p. 26-50.}"
}

@misc{ostrom1987romancing95,
    author = "Ostrom, J. H",
    title = "Romancing the dinosaurs",
    year = "1987",
    howpublished = "The Sciences, v. 27, p. 56-63",
    note = "talkorigins\_source = {true}; raw\_reference = {Ostrom, J. H., 1987, Romancing the dinosaurs: The Sciences, v. 27, p. 56-63.}"
}

@misc{parrish1987cretaceous99,
    author = "Parrish, J. T. et al",
    title = "Cretaceous vertebrates from Alaska - implications for dinosaur ecology",
    year = "1987",
    howpublished = "Geological Society of America, Abstracts with Programs, v. 19, no. 5, p. 326; Abstracts, 40th Annual Meeting, Rocky Mountain Section, GSA",
    note = "talkorigins\_source = {true}; raw\_reference = {Parrish, J. T. et al., 1987, Cretaceous vertebrates from Alaska - implications for dinosaur ecology: Geological Society of America, Abstracts with Programs, v. 19, no. 5, p. 326; Abstracts, 40th Annual Meeting, Rocky Mountain Section, GSA.}"
}

@misc{paul1987the100,
    author = "Paul, G. S",
    title = "The Science and Art of Restoring the Life Appearance of Dinosaurs and Their Relatives, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, II",
    year = "1987",
    howpublished = "Los Angeles, Natural History Museum of Los Angeles County, p. 4-49",
    note = "talkorigins\_source = {true}; raw\_reference = {Paul, G. S., 1987, The Science and Art of Restoring the Life Appearance of Dinosaurs and Their Relatives, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, II: Los Angeles, Natural History Museum of Los Angeles County, p. 4-49.}"
}

@misc{rigby1987the106,
    author = "Rigby, J. K",
    title = "The Last of the North American Dinosaurs, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, II",
    year = "1987",
    howpublished = "Los Angeles, Natural History Museum of Los Angeles County, p. 119-135",
    note = "talkorigins\_source = {true}; raw\_reference = {Rigby, J. K., 1987, The Last of the North American Dinosaurs, in Czerkas, S. J., and Olson, E. C., eds., Dinosaurs Past and Present, II: Los Angeles, Natural History Museum of Los Angeles County, p. 119-135.}"
}

@misc{dixon1988the45,
    author = "Dixon, D. and Cox, B. and Savage, R. J. G. and Gardiner, B",
    title = "The Macmillan Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals",
    year = "1988",
    howpublished = "New York, Macmillan",
    note = "talkorigins\_source = {true}; raw\_reference = {Dixon, D., Cox, B., Savage, R. J. G., and Gardiner, B., 1988, The Macmillan Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals: New York, Macmillan.}"
}

Abstract- Several prominent cladists have questioned the importance of fossils in phylogenctic inference, and it is becoming increasingly popular to simply fit extinct forms, if they are considered at all, to a cladogram of Recent taxa. Gardiner's (1982) and Løvtrup's (1985) study of amniote phylogeny exemplifies this differential treatment, and we focused on that group of organisms to test the proposition that fossils cannot overturn a theory of relationships based only on the Recent biota. Our parsimony analysis of amniote phylogeny, special knowledge contributed by fossils being scrupulously avoided, led to the following best fitting classification, which is similar to the novel hypothesis Gardiner published: (lepidosaurs (turtles (mammals (birds, crocodiles)))). However, adding fossils resulted in a markedly different most parsimonious cladogram of the extant taxa: (mammals (turtles (lepidosaurs (birds, crocodiles)))). That classification is like the traditional hypothesis, and it provides a better fit to the stratigraphic record. To isolate the extinct taxa responsible for the latter classification, the data were successively partitioned with each phylogenetic analysis, and we concluded that: (1) the ingroup, not the outgroup, fossils were important; (2) synapsid, not reptile, fossils were pivotal; (3) certain synapsid fossils, not the earliest or latest, were responsible. The critical nature of the synapsid fossils seemed to lie in the particular combination of primitive and derived character slates they exhibited. Classifying those fossils, along with mammals, as the sister group to the lineage consisting of birds and crocodiles resulted in a relatively poor fit to data; one involving a 2-4 fold increase in evolutionary reversals! Thus, the importance of the critical fossils, collectively or individually, seems to reside in their relative primitive-ness, and the simplest explanation for their more conservative nature is that they have had less time to evolve. While fossils may be important in phylogenetic inference only under certain conditions, there is no compelling reason to prejudge their contribution. We urge systematists to evaluate fairly all of the available evidence.

@article{doi101111j109600311988tb00514x,
    author = "Gauthier, Jacques and Kluge, Arnold G. and Rowe, Timothy",
    title = "AMNIOTE PHYLOGENY AND THE IMPORTANCE OF FOSSILS",
    year = "1988",
    journal = "Cladistics",
    abstract = "Abstract- Several prominent cladists have questioned the importance of fossils in phylogenctic inference, and it is becoming increasingly popular to simply fit extinct forms, if they are considered at all, to a cladogram of Recent taxa. Gardiner's (1982) and Løvtrup's (1985) study of amniote phylogeny exemplifies this differential treatment, and we focused on that group of organisms to test the proposition that fossils cannot overturn a theory of relationships based only on the Recent biota. Our parsimony analysis of amniote phylogeny, special knowledge contributed by fossils being scrupulously avoided, led to the following best fitting classification, which is similar to the novel hypothesis Gardiner published: (lepidosaurs (turtles (mammals (birds, crocodiles)))). However, adding fossils resulted in a markedly different most parsimonious cladogram of the extant taxa: (mammals (turtles (lepidosaurs (birds, crocodiles)))). That classification is like the traditional hypothesis, and it provides a better fit to the stratigraphic record. To isolate the extinct taxa responsible for the latter classification, the data were successively partitioned with each phylogenetic analysis, and we concluded that: (1) the ingroup, not the outgroup, fossils were important; (2) synapsid, not reptile, fossils were pivotal; (3) certain synapsid fossils, not the earliest or latest, were responsible. The critical nature of the synapsid fossils seemed to lie in the particular combination of primitive and derived character slates they exhibited. Classifying those fossils, along with mammals, as the sister group to the lineage consisting of birds and crocodiles resulted in a relatively poor fit to data; one involving a 2-4 fold increase in evolutionary reversals! Thus, the importance of the critical fossils, collectively or individually, seems to reside in their relative primitive-ness, and the simplest explanation for their more conservative nature is that they have had less time to evolve. While fossils may be important in phylogenetic inference only under certain conditions, there is no compelling reason to prejudge their contribution. We urge systematists to evaluate fairly all of the available evidence.",
    url = "https://doi.org/10.1111/j.1096-0031.1988.tb00514.x",
    doi = "10.1111/j.1096-0031.1988.tb00514.x",
    openalex = "W1978557909",
    references = "crossref1943the, currie1985cranial, doi101001jama194302840160064031, doi1010079781468488517, doi101007978146848851721, doi101016002555648290027x, doi1010160169534789901626, doi101016b9781483198279500198, doi101016b9781483231426500124, doi101017cbo9780511693281002, doi101038142004a0, doi10108002724634198810011708, doi101086628623, doi101093sysbio1811, doi101093sysbio33183, doi1010970000505319311100000026, doi101098rstb19830079, doi101111j109636421977tb01031x, doi101111j109636421985tb01796x, doi101146annureven10010165000525, doi1023071005355, doi1023071220820, doi1023071292217, doi1023071441916, doi1023072412407, doi1023072412685, doi1023072413134, doi1023072413259, doi1023072413454, doi1023072485224, doi105281zenodo16171435, doi10560219780801847806, doi105962bhltitle6408, doi105962bhltitle82144, openalexw1534787790, openalexw1534857865, openalexw2954279587, openalexw2983381470, openalexw3146596760, openalexw3184837389, openalexw575222456, roaf1943the"
}

@misc{horner1988digging66,
    author = "Horner, J. R. and Gorman, J",
    title = "Digging Dinosaurs",
    year = "1988",
    howpublished = "New York, Workman",
    note = "talkorigins\_source = {true}; raw\_reference = {Horner, J. R., and Gorman, J., 1988, Digging Dinosaurs: New York, Workman.}"
}

The record of life on land has been a principal concern of historical biology not only because of our fascination with our own past (and with giants, dragons, and other ancient monsters) but because of special opportunities and challenges for development of methods, principles, and concepts of explanation. The Beginning of the Age of Dinosaurs treats an intriguing phase of that history, one that included the first appearance of dinosaurs, and mammals, the extinction or near extinction of many clades of vertebrates, and extensive changes in plant associations. Further, the patterns of change (and of stasis) raise general questions about macroecologic and macroevolutionary processes and factors and even about the roles of chance and determination in biological history. Although the book was published initially in 1986 (and was based on a 1984 symposium sponsored by the Society of Vertebrate Paleontologists), its content remains current and its release in paperback form (for $34.50 rather than $75.00 for the hardcover version) justifies a review even at this late date. The Introduction and the Summary and Prospectus, written by the editor, Kevin Padian, demonstrate the significance of the interval from mid-Triassic to early Jurassic-particularly for vertebrates on land. Advanced mammal-like reptiles (therapsids) dominate lower Triassic assemblages in abundance, taxonomic diversity, and ecological variety; non-therapsids (mostly archosaurs) are rare elements and apparently of little ecological importance. In upper Triassic and lower Jurassic assemblages the situation is reversed, therapsids rare with limited diversity and variety but archosaurs abundant, diverse and varied. The archosaur expansion starts in middle of the succession; pterodactyls, crocodylomorphs, and dinosaurs appear (as archosaur subclades) in approximate coincidence with a marked decline in therapsids. Mammals (at least 3 subclades) occur along with two other subclades of very mammal-like therapsids very close to the top. In the upper Triassic two relatively sharp breaks in faunal composition appear, one relatively low, in the top of the Carnian and base of the Norian stages (around 225 Ma), and one higher, at the top of the Norian (around 215 Ma). These breaks, if real and not a consequence of miscorrelations or gaps in sampling, suggest high rates of taxonomic extinction and origination and have been interpreted as intervals of catastrophic extinction. These changes coincide more or less with some in the flora (except that the latter seem continuous rather than stepped) and thus with overall changes in terrestrial ecosystems. Radically different explanations have been offered for these patterns, at one extreme a deterministic argument from the competitive superiority of dinosaurs to the other, an opportunistic one based on chance differences in survival through episodes of mass extinction. This book can be viewed (and reviewed) as an extended example of analysis and interpretation in historical biology. The concerns of the discipline are twofold, chronicle and narrative (the concepts those of O'Hara, 1988). Chronicle comprises when, what, and where; narrative, how. A chronicle extends of course beyond description and chronologic ordering of fossils to paleobiogeographic, paleoecologic, and phylogenetic reconstructions. The latter derive from patterns in form and occurrence of fossils as analyzed in terms of taphonomic, constructional, functional, and phylogenetic processes and factors (viz Seilacher, 1970) and of stratigraphic and geographic distribution. Each reconstruction represents a particular state, and stratigraphic analysis arranges these reconstructions into a chronicle. Narrative, in contrast, involves explanation of the patterns (temporal, geographic, ecologic and phyletic) in the chronicle by a sequence of biological and physical circumstances and by evolutionary processes and factors (genetic, phylogenetic, and ecological). Of the 26 papers in this volume, 24 focus primarily on the chronicle and are dominated by consideration of what-when, i.e., the stratigraphic distribution of various groups of fossils, and of what-how, i.e., the phylogenetic and functional analyses. Among those in the what-when group are papers by Colbert on historical aspects of upper Triassic-lower Jurassic stratigraphy, by Ash on fossil plants, by Olsen and Baird on the ichnogenus Atreipus, by Chatterjee and by Parrish and Carpenter on vertebrates of the Dockum Group (Texas and New Mexico), and by Long and Padian on biostratigraphy of the Chinle Formation (Arizona). Also best included here are the studies by McCune and Schaeffer on Triassic and Jurassic fishes, Gaffney on turtles, Clemens on mammals, Olson and Padian on crocodylomorph ichnogenera, Sun and Cui on saurishians from the lower Lufeng (China), Clark and Fastovsky on the vertebrates of the Glen Canyon Group (Arizona), Haubold on archosaur trackways, Sigogneau-Russell, Frank, and Hemmerle on a new family of Triassic

@article{doi1023073514751,
    author = "Beerbower, Richard and Padian, Kevin",
    title = "The Beginning of the Age of Dinosaurs",
    year = "1989",
    journal = "Palaios",
    abstract = "The record of life on land has been a principal concern of historical biology not only because of our fascination with our own past (and with giants, dragons, and other ancient monsters) but because of special opportunities and challenges for development of methods, principles, and concepts of explanation. The Beginning of the Age of Dinosaurs treats an intriguing phase of that history, one that included the first appearance of dinosaurs, and mammals, the extinction or near extinction of many clades of vertebrates, and extensive changes in plant associations. Further, the patterns of change (and of stasis) raise general questions about macroecologic and macroevolutionary processes and factors and even about the roles of chance and determination in biological history. Although the book was published initially in 1986 (and was based on a 1984 symposium sponsored by the Society of Vertebrate Paleontologists), its content remains current and its release in paperback form (for $34.50 rather than $75.00 for the hardcover version) justifies a review even at this late date. The Introduction and the Summary and Prospectus, written by the editor, Kevin Padian, demonstrate the significance of the interval from mid-Triassic to early Jurassic-particularly for vertebrates on land. Advanced mammal-like reptiles (therapsids) dominate lower Triassic assemblages in abundance, taxonomic diversity, and ecological variety; non-therapsids (mostly archosaurs) are rare elements and apparently of little ecological importance. In upper Triassic and lower Jurassic assemblages the situation is reversed, therapsids rare with limited diversity and variety but archosaurs abundant, diverse and varied. The archosaur expansion starts in middle of the succession; pterodactyls, crocodylomorphs, and dinosaurs appear (as archosaur subclades) in approximate coincidence with a marked decline in therapsids. Mammals (at least 3 subclades) occur along with two other subclades of very mammal-like therapsids very close to the top. In the upper Triassic two relatively sharp breaks in faunal composition appear, one relatively low, in the top of the Carnian and base of the Norian stages (around 225 Ma), and one higher, at the top of the Norian (around 215 Ma). These breaks, if real and not a consequence of miscorrelations or gaps in sampling, suggest high rates of taxonomic extinction and origination and have been interpreted as intervals of catastrophic extinction. These changes coincide more or less with some in the flora (except that the latter seem continuous rather than stepped) and thus with overall changes in terrestrial ecosystems. Radically different explanations have been offered for these patterns, at one extreme a deterministic argument from the competitive superiority of dinosaurs to the other, an opportunistic one based on chance differences in survival through episodes of mass extinction. This book can be viewed (and reviewed) as an extended example of analysis and interpretation in historical biology. The concerns of the discipline are twofold, chronicle and narrative (the concepts those of O'Hara, 1988). Chronicle comprises when, what, and where; narrative, how. A chronicle extends of course beyond description and chronologic ordering of fossils to paleobiogeographic, paleoecologic, and phylogenetic reconstructions. The latter derive from patterns in form and occurrence of fossils as analyzed in terms of taphonomic, constructional, functional, and phylogenetic processes and factors (viz Seilacher, 1970) and of stratigraphic and geographic distribution. Each reconstruction represents a particular state, and stratigraphic analysis arranges these reconstructions into a chronicle. Narrative, in contrast, involves explanation of the patterns (temporal, geographic, ecologic and phyletic) in the chronicle by a sequence of biological and physical circumstances and by evolutionary processes and factors (genetic, phylogenetic, and ecological). Of the 26 papers in this volume, 24 focus primarily on the chronicle and are dominated by consideration of what-when, i.e., the stratigraphic distribution of various groups of fossils, and of what-how, i.e., the phylogenetic and functional analyses. Among those in the what-when group are papers by Colbert on historical aspects of upper Triassic-lower Jurassic stratigraphy, by Ash on fossil plants, by Olsen and Baird on the ichnogenus Atreipus, by Chatterjee and by Parrish and Carpenter on vertebrates of the Dockum Group (Texas and New Mexico), and by Long and Padian on biostratigraphy of the Chinle Formation (Arizona). Also best included here are the studies by McCune and Schaeffer on Triassic and Jurassic fishes, Gaffney on turtles, Clemens on mammals, Olson and Padian on crocodylomorph ichnogenera, Sun and Cui on saurishians from the lower Lufeng (China), Clark and Fastovsky on the vertebrates of the Glen Canyon Group (Arizona), Haubold on archosaur trackways, Sigogneau-Russell, Frank, and Hemmerle on a new family of Triassic",
    url = "https://doi.org/10.2307/3514751",
    doi = "10.2307/3514751",
    openalex = "W2320472492",
    references = "doi101017cbo9780511608551, doi1023072807146, doi1023072992272"
}

@misc{farlow1989paleobiology56,
    author = "Farlow, J. O",
    title = "Paleobiology of the Dinosaurs, 238 of GSA Special Paper",
    year = "1989",
    howpublished = "Boulder, Colorado, Geological Society of America, 100 p.; Based on a Meeting, Waco, Tx., March, 1987",
    note = "talkorigins\_source = {true}; raw\_reference = {Farlow, J. O., 1989, Paleobiology of the Dinosaurs, 238 of GSA Special Paper: Boulder, Colorado, Geological Society of America, 100 p.; Based on a Meeting, Waco, Tx., March, 1987.}"
}

@misc{morris1989how88,
    author = "Morris, J. D",
    title = "How Do the Dinosaurs Fit In?",
    year = "1989",
    howpublished = "Acts and Facts, v. 18, no. 5, p. d",
    note = "talkorigins\_source = {true}; raw\_reference = {Morris, J. D., 1989, How Do the Dinosaurs Fit In?: Acts and Facts, v. 18, no. 5, p. d.}"
}

@misc{leipzig1990the74,
    author = "Leipzig, M. R",
    title = "The Encyclopedia Archosauria [1st ed.]",
    year = "1990",
    howpublished = "Pittsburgh, Pa., Carnegie Museum of Natural History, 863 p",
    note = "talkorigins\_source = {true}; raw\_reference = {Leipzig, M. R., 1990, The Encyclopedia Archosauria [1st ed.]: Pittsburgh, Pa., Carnegie Museum of Natural History, 863 p.}"
}

Fossil bird skeletons discovered in Lower Cretaceous lake deposits in China shed new light on the early evolution of avian flight and perching. The 135 million-year-old sparrow-sized skeletons represent a new avian, Sinornis santensis, n. gen. n. sp., that preserves striking primitive features such as a flexible manus with unguals, a footed pubis, and stomach ribs (gastralia). In contrast to Archaeoperyx, however, Sinornis exhibits advanced features such as a broad sternum, wing-folding mechanism, pygostyle, and large fully reversed hallux. Modern avian flight function and perching capability, therefore, must have evolved in small-bodied birds in inland habitats not long after Archaeopteryx.

@article{doi101126science2555046845,
    author = "Sereno, Paul C. and Chenggang, Rao",
    title = "Early Evolution of Avian Flight and Perching: New Evidence from the Lower Cretaceous of China",
    year = "1992",
    journal = "Science",
    abstract = "Fossil bird skeletons discovered in Lower Cretaceous lake deposits in China shed new light on the early evolution of avian flight and perching. The 135 million-year-old sparrow-sized skeletons represent a new avian, Sinornis santensis, n. gen. n. sp., that preserves striking primitive features such as a flexible manus with unguals, a footed pubis, and stomach ribs (gastralia). In contrast to Archaeoperyx, however, Sinornis exhibits advanced features such as a broad sternum, wing-folding mechanism, pygostyle, and large fully reversed hallux. Modern avian flight function and perching capability, therefore, must have evolved in small-bodied birds in inland habitats not long after Archaeopteryx.",
    url = "https://doi.org/10.1126/science.255.5046.845",
    doi = "10.1126/science.255.5046.845",
    openalex = "W2095317708",
    references = "doi1010160031018275900115, doi101038022457a0, doi101038331433a0, doi101098rstb19910056, doi101111j1469185x1979tb01013x, doi101111j146979981990tb04039x, doi101111j1474919x1973tb02636x, doi101126science20343841021, doi101126science24148721495, gregor1988the"
}

A comprehensive and illustrated review of fossil vertebrate tracks known to date from the Western United States extending from Texas to California and from Arizona to Washington. Includes tracks from the Paleozoic, Triassic, Jurassic, Cretaceous, and Cenozoic Eras. Also provides insight on the scientific importance, identification, and preservation of fossil footprints.

@book{doi107312lock90868,
    author = "Lockley, Martin G. and Hunt, Adrian P.",
    title = "Dinosaur Tracks and Other Fossil Footprints of the Western United States",
    year = "1995",
    booktitle = "Columbia University Press eBooks",
    abstract = "A comprehensive and illustrated review of fossil vertebrate tracks known to date from the Western United States extending from Texas to California and from Arizona to Washington. Includes tracks from the Paleozoic, Triassic, Jurassic, Cretaceous, and Cenozoic Eras. Also provides insight on the scientific importance, identification, and preservation of fossil footprints.",
    url = "https://doi.org/10.7312/lock90868",
    doi = "10.7312/lock90868",
    openalex = "W4300932534"
}

@book{doi1010079781489928757,
    author = "Bromley, Richard G.",
    title = "Trace Fossils",
    year = "1996",
    url = "https://doi.org/10.1007/978-1-4899-2875-7",
    doi = "10.1007/978-1-4899-2875-7",
    openalex = "W4243579108"
}

ABSTRACT Closure of neurocentral sutures in the crocodylian vertebral column follows a distinct caudal to cranial sequence during ontogeny. The sutures in most caudal vertebrae are fully closed at hatching, but closure of remaining sutures occurs later in ontogeny. Closure of cervical sutures is a consistent indicator of morphological maturity in Alligator mississippiensis, Alligator sinensis, Osteolaemus tetraspis, and Crocodylus acutus; the final transformation is the closure of the axial neurocentral suture, which occurs after the closure of the axis-odontoid suture. Because these transformations occur near the end of ontogeny in all three taxa, regardless of maximum size, closure of these sutures is a size-independent criterion of maturity; however, it is not certain if suture closure indicates the stoppage of growth. These transformations are readily identifiable in fossils, permitting the objective characterization of maturity in fossil crocodylians and possibly at least some of their closer extinct relatives.

@article{doi10108002724634199610011283,
    author = "Brochu, Christopher A.",
    title = "Closure of neurocentral sutures during crocodilian ontogeny: Implications for maturity assessment in fossil archosaurs",
    year = "1996",
    journal = "Journal of Vertebrate Paleontology",
    abstract = "ABSTRACT Closure of neurocentral sutures in the crocodylian vertebral column follows a distinct caudal to cranial sequence during ontogeny. The sutures in most caudal vertebrae are fully closed at hatching, but closure of remaining sutures occurs later in ontogeny. Closure of cervical sutures is a consistent indicator of morphological maturity in Alligator mississippiensis, Alligator sinensis, Osteolaemus tetraspis, and Crocodylus acutus; the final transformation is the closure of the axial neurocentral suture, which occurs after the closure of the axis-odontoid suture. Because these transformations occur near the end of ontogeny in all three taxa, regardless of maximum size, closure of these sutures is a size-independent criterion of maturity; however, it is not certain if suture closure indicates the stoppage of growth. These transformations are readily identifiable in fossils, permitting the objective characterization of maturity in fossil crocodylians and possibly at least some of their closer extinct relatives.",
    url = "https://doi.org/10.1080/02724634.1996.10011283",
    doi = "10.1080/02724634.1996.10011283",
    openalex = "W2024771330",
    references = "doi101002jmor1051080103, doi101017s0094837300012331, doi101086273307, doi101111j109636421993tb02537x, doi101111j146979981975tb01405x, doi101111j146979981993tb01933x, doi1023071444994, doi1023072403875, doi105962bhltitle54967, doi105962bhltitle82144, houck1990allometric"
}

Late Jurassic and Early Cretaceous birds from northeastern China, including many complete skeletons of Confuciusornis, provide evidence for a fundamental dichotomy in the class Aves that may antedate the temporal occurrence of the Late Jurassic Archaeopteryx. The abundance of Confuciusornis may provide evidence of avian social behavior. Jurassic skeletal remains of an ornithurine bird lend further support to the idea of an early separation of the line that gave rise to modern birds. Chaoyangia, an ornithurine bird from the Early Cretaceous of China, has premaxillary teeth.

@article{doi101126science27452901164,
    author = "Hou, Lianhai and Martin, Larry D. and Zhou, Zhonghe and Feduccia, Alan",
    title = "Early Adaptive Radiation of Birds: Evidence from Fossils from Northeastern China",
    year = "1996",
    journal = "Science",
    abstract = "Late Jurassic and Early Cretaceous birds from northeastern China, including many complete skeletons of Confuciusornis, provide evidence for a fundamental dichotomy in the class Aves that may antedate the temporal occurrence of the Late Jurassic Archaeopteryx. The abundance of Confuciusornis may provide evidence of avian social behavior. Jurassic skeletal remains of an ornithurine bird lend further support to the idea of an early separation of the line that gave rise to modern birds. Chaoyangia, an ornithurine bird from the Early Cretaceous of China, has premaxillary teeth.",
    url = "https://doi.org/10.1126/science.274.5290.1164",
    doi = "10.1126/science.274.5290.1164",
    openalex = "W2085960960"
}

ABSTRACT The most commonly cited apomorphy of Archosauriformes is an opening in the snout known as the antorbital cavity. Despite the ubiquity and prominence of the antorbital cavity, its function and importance in craniofacial evolution have been problematic. Discovering the significance of the antorbital cavity is a two step process: first, establishing the function of the bony cavity (that is, its soft-tissue relations), and second, determining the biological role of the enclosed structure. The first step is the most fundamental, and hence is examined at length. Three hypotheses for the function of the antorbital cavity have been advanced, suggesting that it housed (1) a gland, (2) a muscle, or (3) a paranasal air sinus. Thus, resolution is correctly viewed as a “soft-tissue problem,” and is addressed within the context of the extant phylogenetic bracket (EPB) approach for reconstructing the unpreserved features of fossil organisms. The soft-anatomical relations of the antorbital cavity (or any bony structure) are important because (1) soft tissues generally have morphogenetic primacy over bony tissues and (2) inferences about soft tissues are the foundation for a cascading suite of paleobiological inferences. The EPB approach uses the shared causal associations between soft tissues and their osteological correlates (i.e., the signatures imparted to the bones by the soft tissues) that are observed in the extant outgroups of the fossil taxon of interest to infer the soft-anatomical attributes of the fossil; based on the assessment at the outgroup node, a hierarchy characterizing the strength of the inference can be constructed. This general approach is applied to the problem of the function of the antorbital cavity, taking each hypothesized soft-tissue candidate—gland, muscle, and air sac—in turn, (1) establishing the osteological correlates of each soft-tissue system in the EPB of any fossil archosaur (i.e., extant birds and crocodilians), (2) formulating a hypothesis of homology based on similarities in these causal associations between birds and crocodilians, (3) testing this hypothesis by surveying fossil archosaurs for the specified osteological correlates, and (4) accepting or rejecting the hypothesis based on its phylogenetic congruence. Using this approach, fossil archosaurs can be reliably reconstructed with a Glandula nasalis, M. pterygoideus, pars dorsalis, and Sinus antorbitalis that are homologous with those of extant archosaurs; however, the osteological correlates of only the antorbital paranasal air sinus involve the several structures associated with the antorbital cavity. Additional evidence for the pneumatic nature of the antorbital cavity comes from the presence of numerous accessory cavities (especially in theropod dinosaurs) surrounding the main antorbital cavity. To address the origin of the antorbital cavity, the EPB approach was applied to basal archosauriforms; the data are not as robust, but nevertheless suggest that the cavity appeared as a housing for a paranasal air sinus. The second step in discovering the evolutionary significance of the antorbital cavity is to assess the function of the enclosed paranasal air sac. In fact, the function of all pneumaticity is investigated here. Rather than the enclosed volume of air (i.e., the empty space) being functionally important, better explanations result by focusing on the pneumatic epithelial diverticulum itself. It is proposed here that the function of the epithelial air sac is simply to pneumatize bone in an opportunistic manner within the constraints of a particular biomechanical loading regime. Trends in facial evolution in three clades of archosaurs (crocodylomorphs, ornithopod dinosaurs, and theropod dinosaurs) were examined in light of this new perspective. Crocodylomorphs and ornithopods both show trends for reduction and enclosure of the antorbital cavity (but for different reasons), whereas theropods show a trend for relatively poorly constrained expansion. These findings are consistent with the view of air sacs as opportunistic pneumatizing machines, with weight reduction and design optimality as secondary effects.

@article{doi10108002724634199710011027,
    author = "Witmer, Lawrence M.",
    title = "The Evolution of the Antorbital Cavity of Archosaurs: A Study in Soft-Tissue Reconstruction in the Fossil Record with an Analysis of the Function of Pneumaticity",
    year = "1997",
    journal = "Journal of Vertebrate Paleontology",
    abstract = "ABSTRACT The most commonly cited apomorphy of Archosauriformes is an opening in the snout known as the antorbital cavity. Despite the ubiquity and prominence of the antorbital cavity, its function and importance in craniofacial evolution have been problematic. Discovering the significance of the antorbital cavity is a two step process: first, establishing the function of the bony cavity (that is, its soft-tissue relations), and second, determining the biological role of the enclosed structure. The first step is the most fundamental, and hence is examined at length. Three hypotheses for the function of the antorbital cavity have been advanced, suggesting that it housed (1) a gland, (2) a muscle, or (3) a paranasal air sinus. Thus, resolution is correctly viewed as a “soft-tissue problem,” and is addressed within the context of the extant phylogenetic bracket (EPB) approach for reconstructing the unpreserved features of fossil organisms. The soft-anatomical relations of the antorbital cavity (or any bony structure) are important because (1) soft tissues generally have morphogenetic primacy over bony tissues and (2) inferences about soft tissues are the foundation for a cascading suite of paleobiological inferences. The EPB approach uses the shared causal associations between soft tissues and their osteological correlates (i.e., the signatures imparted to the bones by the soft tissues) that are observed in the extant outgroups of the fossil taxon of interest to infer the soft-anatomical attributes of the fossil; based on the assessment at the outgroup node, a hierarchy characterizing the strength of the inference can be constructed. This general approach is applied to the problem of the function of the antorbital cavity, taking each hypothesized soft-tissue candidate—gland, muscle, and air sac—in turn, (1) establishing the osteological correlates of each soft-tissue system in the EPB of any fossil archosaur (i.e., extant birds and crocodilians), (2) formulating a hypothesis of homology based on similarities in these causal associations between birds and crocodilians, (3) testing this hypothesis by surveying fossil archosaurs for the specified osteological correlates, and (4) accepting or rejecting the hypothesis based on its phylogenetic congruence. Using this approach, fossil archosaurs can be reliably reconstructed with a Glandula nasalis, M. pterygoideus, pars dorsalis, and Sinus antorbitalis that are homologous with those of extant archosaurs; however, the osteological correlates of only the antorbital paranasal air sinus involve the several structures associated with the antorbital cavity. Additional evidence for the pneumatic nature of the antorbital cavity comes from the presence of numerous accessory cavities (especially in theropod dinosaurs) surrounding the main antorbital cavity. To address the origin of the antorbital cavity, the EPB approach was applied to basal archosauriforms; the data are not as robust, but nevertheless suggest that the cavity appeared as a housing for a paranasal air sinus. The second step in discovering the evolutionary significance of the antorbital cavity is to assess the function of the enclosed paranasal air sac. In fact, the function of all pneumaticity is investigated here. Rather than the enclosed volume of air (i.e., the empty space) being functionally important, better explanations result by focusing on the pneumatic epithelial diverticulum itself. It is proposed here that the function of the epithelial air sac is simply to pneumatize bone in an opportunistic manner within the constraints of a particular biomechanical loading regime. Trends in facial evolution in three clades of archosaurs (crocodylomorphs, ornithopod dinosaurs, and theropod dinosaurs) were examined in light of this new perspective. Crocodylomorphs and ornithopods both show trends for reduction and enclosure of the antorbital cavity (but for different reasons), whereas theropods show a trend for relatively poorly constrained expansion. These findings are consistent with the view of air sacs as opportunistic pneumatizing machines, with weight reduction and design optimality as secondary effects.",
    url = "https://doi.org/10.1080/02724634.1997.10011027",
    doi = "10.1080/02724634.1997.10011027",
    openalex = "W1973023986",
    references = "coria1995a, crossref1976allosaurus, currie1985cranial, doi10100797836426953391, doi1010160021929082902469, doi101016b9781483231426500124, doi101017s0022336000026706, doi101017s0022336000059126, doi101017s0094837300004310, doi101017s247526300000091x, doi101038019118a0, doi101038063003a0, doi101038114085a0, doi10108002724634199110011386, doi10108002724634199110011426, doi10108002724634199210011473, doi10108002724634199310011511, doi10108002724634199410011538, doi10108002724634199510011250, doi101098rstb19610007, doi101098rstb19650003, doi101098rstb19850092, doi101098rstb19910056, doi101098rstb19920117, doi101098rstb19950125, doi101111j109600311991tb00045x, doi101111j109636421978tb01049x, doi101111j146363951921tb00489x, doi101111j1469185x1990tb01427x, doi101111j146979981913tb06148x, doi101111j155856461965tb01720x, doi101111j174966321940tb57047x, doi101111j216409471940tb00068x, doi101126science11282807, doi101126science2665183267, doi101126science2725264986, doi101139e93179, doi10125900071285586941029, doi1015468p4gnhz, doi1015468yhxmzl, doi1023072406439, doi1023072413454, doi1023072421859, doi1023072992444, doi10230730135049, doi1023073514548, doi105281zenodo16171435, doi105281zenodo16673433, doi105479si03629236110i, doi105860choice326223, doi105962bhlpart22965, doi105962bhltitle54054, doi105962p226819, madsen1976a, openalexw1489366593, openalexw1534857865, openalexw193970361, openalexw2603028126, openalexw2788234611, openalexw3140893762, openalexw3184837389, openalexw607142922, openalexw616953834, rowe1989a, sues1978a, walker1964triassic"
}

▪ Abstract Phylogenetic studies and new fossil evidence have yielded fundamental insights into the pattern and timing of dinosaur evolution and the emergence of functionally modern birds. The dinosaurian radiation began in the Middle Triassic, significantly predating the global dominance of dinosaurs by the end of the period. The phylogenetic history of ornithischian and saurischian dinosaurs reveals evolutionary trends such as increasing body size. Adaptations to herbivory in dinosaurs were not tightly correlated with marked floral replacements. Dinosaurian biogeography during the era of continental breakup principally involved dispersal and regional extinction.

@article{sereno1997the,
    author = "Sereno, Paul C.",
    title = "THE ORIGIN AND EVOLUTION OF DINOSAURS",
    year = "1997",
    journal = "Annual Review of Earth and Planetary Sciences",
    abstract = "▪ Abstract Phylogenetic studies and new fossil evidence have yielded fundamental insights into the pattern and timing of dinosaur evolution and the emergence of functionally modern birds. The dinosaurian radiation began in the Middle Triassic, significantly predating the global dominance of dinosaurs by the end of the period. The phylogenetic history of ornithischian and saurischian dinosaurs reveals evolutionary trends such as increasing body size. Adaptations to herbivory in dinosaurs were not tightly correlated with marked floral replacements. Dinosaurian biogeography during the era of continental breakup principally involved dispersal and regional extinction.",
    url = "https://doi.org/10.1146/annurev.earth.25.1.435",
    doi = "10.1146/annurev.earth.25.1.435",
    number = "1",
    openalex = "W2081551955",
    pages = "435-489",
    volume = "25",
    references = "benton1983dinosaur, chinsamy1994dinosaur, crossref1976allosaurus, crossref1995systematics, doi101007978364268836217, doi10100797836426953391, doi1010160031018272900491, doi1010160195667191900155, doi101017cbo9780511608551, doi101017cbo9781139167826, doi101017s0022336000026706, doi101017s0094837300004310, doi101038274661a0, doi101038378774a0, doi101038385247a0, doi10108002724634199110011426, doi10108002724634199310011490, doi10108002724634199410011538, doi10108002724634199510011250, doi10108002724634199510011575, doi101086284406, doi101086407902, doi101093clinids222240, doi101098rstb19910056, doi101098rstb19950125, doi101111j109583121976tb00244x, doi101111j109600311988tb00514x, doi101126science24348951145, doi101126science2555046845, doi101126science2645160828, doi101126science2665183267, doi101126science2665186779, doi101126science2725264986, doi101139e93176, doi101139e93179, doi101139e93187, doi101146annurevea03050175000415, doi101146annureven10010165000525, doi101353book34649, doi1023071441916, doi1023072421859, doi105281zenodo16171435, doi105281zenodo16246150, doi105479si03629236110i, doi105860choice323881, doi105860choice331556, doi105962p226819, openalexw2603028126, openalexw2788234611, openalexw3146596760, openalexw39955589, parrish1987late, rowe1989a, vonhuene1923carnivorous, wilson1985stenonychosaurus"
}

@article{doi101016s0031018297001089,
    author = "Markwick, Paul",
    title = "Fossil crocodilians as indicators of Late Cretaceous and Cenozoic climates: implications for using palaeontological data in reconstructing palaeoclimate",
    year = "1998",
    journal = "Palaeogeography Palaeoclimatology Palaeoecology",
    url = "https://doi.org/10.1016/s0031-0182(97)00108-9",
    doi = "10.1016/s0031-0182(97)00108-9",
    openalex = "W2092060384",
    references = "doi10100797814899503456, doi10100797894011125435, doi1010160031018265900131, doi101016003101829290096n, doi101016003192018990263x, doi1010160195667191900155, doi101017s0094837300006060, doi101029pa002i001p00001, doi1010719781486309702, doi101098rstb19930109, doi101126science19142321131, doi101126science24148691043, doi10113000917613198614535scaia20co2, doi101146annurevph57030195000441, doi102110pec88010071, doi1023071444927, doi1023071563593, doi1023073514444, doi1023073514548, doi1023073669094, doi102973odpprocsr1192001991, openalexw2983381470, openalexw575222456, spotila1973a"
}

Recent discoveries of fossil vertebrates from the Late Cretaceous of Madagascar include several specimens of a large theropod dinosaur. One specimen includes a nearly complete and exquisitely preserved skull with thickened pneumatic nasals, a median frontal horn, and a dorsal projection on the parietals. The new materials are assigned to the enigmatic theropod group Abelisauridae on the basis of a number of unique features. Fossil remains attributable to abelisaurids are restricted to three Gondwanan landmasses: South America, Madagascar, and the Indian subcontinent. This distribution is consistent with a revised paleogeographic reconstruction that posits prolonged links between these landmasses (via Antarctica), perhaps until late in the Late Cretaceous.

@article{doi101126science28053661048,
    author = "Sampson, Scott D. and Witmer, Lawrence M. and Forster, Catherine A. and Krause, David W. and O’Connor, Patrick M. and Dodson, Peter and Ravoavy, Florent",
    title = "Predatory Dinosaur Remains from Madagascar: Implications for the Cretaceous Biogeography of Gondwana",
    year = "1998",
    journal = "Science",
    abstract = "Recent discoveries of fossil vertebrates from the Late Cretaceous of Madagascar include several specimens of a large theropod dinosaur. One specimen includes a nearly complete and exquisitely preserved skull with thickened pneumatic nasals, a median frontal horn, and a dorsal projection on the parietals. The new materials are assigned to the enigmatic theropod group Abelisauridae on the basis of a number of unique features. Fossil remains attributable to abelisaurids are restricted to three Gondwanan landmasses: South America, Madagascar, and the Indian subcontinent. This distribution is consistent with a revised paleogeographic reconstruction that posits prolonged links between these landmasses (via Antarctica), perhaps until late in the Late Cretaceous.",
    url = "https://doi.org/10.1126/science.280.5366.1048",
    doi = "10.1126/science.280.5366.1048",
    openalex = "W2026696841",
    references = "doi101016003101829190145h, doi101017s0022336000026706, doi10103837343, doi101038377301a0, doi101126science2665183267, doi101126science2725264986, doi101126science27953581915, doi101139e93176, doi101146annurevearth251435, doi105962p226819, openalexw648313615, sereno1997the"
}

The Triassic-Jurassic boundary marks a major faunal mass extinction, but records of accompanying environmental changes are limited. Paleobotanical evidence indicates a fourfold increase in atmospheric carbon dioxide concentration and suggests an associated 3 degrees to 4 degrees C "greenhouse" warming across the boundary. These environmental conditions are calculated to have raised leaf temperatures above a highly conserved lethal limit, perhaps contributing to the >95 percent species-level turnover of Triassic-Jurassic megaflora.

@article{doi101126science28554321386,
    author = "McElwain, Jennifer C. and Beerling, David J. and Woodward, F. I.",
    title = "Fossil Plants and Global Warming at the Triassic-Jurassic Boundary",
    year = "1999",
    journal = "Science",
    abstract = {The Triassic-Jurassic boundary marks a major faunal mass extinction, but records of accompanying environmental changes are limited. Paleobotanical evidence indicates a fourfold increase in atmospheric carbon dioxide concentration and suggests an associated 3 degrees to 4 degrees C "greenhouse" warming across the boundary. These environmental conditions are calculated to have raised leaf temperatures above a highly conserved lethal limit, perhaps contributing to the >95 percent species-level turnover of Triassic-Jurassic megaflora.},
    url = "https://doi.org/10.1126/science.285.5432.1386",
    doi = "10.1126/science.285.5432.1386",
    openalex = "W2007663434",
    references = "doi1010160034666777900070, doi1010160034666780900226, doi1010160034666781900695, doi101093oso97801985491780010001, doi101126science21545391501, doi101126science2845414616, doi101126science3616622, doi101126science7701342, doi101144gsjgs15450773"
}

ABSTRACT It has long been assumed that the extant bilaterian phyla generally have their origin in the Cambrian explosion, when they appear in an essentially modern form. Both these assumptions are questionable. A strict application of stem‐ and crown‐group concepts to phyla shows that although the branching points of many clades may have occurred in the Early Cambrian or before, the appearance of the modern body plans was in most cases later: very few bilaterian phyla sensu stricto have demonstrable representatives in the earliest Cambrian. Given that the early branching points of major clades is an inevitable result of the geometry of clade diversification, the alleged phenomenon of phyla appearing early and remaining morphologically static is seen not to require particular explanation. Confusion in the definition of a phylum has thus led to attempts to explain (especially from a developmental perspective) a feature that is partly inevitable, partly illusory. We critically discuss models for Proterozoic diversification based on small body size, limited developmental capacity and poor preservation and cryptic habits, and show that the prospect of lineage diversification occurring early in the Proterozoic can be seen to be unlikely on grounds of both parsimony and functional morphology. Indeed, the combination of the body and trace fossil record demonstrates a progressive diversification through the end of the Proterozoic well into the Cambrian and beyond, a picture consistent with body plans being assembled during this time. Body‐plan characters are likely to have been acquired monophyletically in the history of the bilaterians, and a model explaining the diversity in just one of them, the coelom, is presented. This analysis points to the requirement for a careful application of systematic methodology before explanations are sought for alleged patterns of constraint and flexibility.

@article{doi101111j1469185x1999tb00046x,
    author = "Budd, Graham E. and Jensen, Sören",
    title = "A critical reappraisal of the fossil record of the bilaterian phyla",
    year = "2000",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    abstract = "ABSTRACT It has long been assumed that the extant bilaterian phyla generally have their origin in the Cambrian explosion, when they appear in an essentially modern form. Both these assumptions are questionable. A strict application of stem‐ and crown‐group concepts to phyla shows that although the branching points of many clades may have occurred in the Early Cambrian or before, the appearance of the modern body plans was in most cases later: very few bilaterian phyla sensu stricto have demonstrable representatives in the earliest Cambrian. Given that the early branching points of major clades is an inevitable result of the geometry of clade diversification, the alleged phenomenon of phyla appearing early and remaining morphologically static is seen not to require particular explanation. Confusion in the definition of a phylum has thus led to attempts to explain (especially from a developmental perspective) a feature that is partly inevitable, partly illusory. We critically discuss models for Proterozoic diversification based on small body size, limited developmental capacity and poor preservation and cryptic habits, and show that the prospect of lineage diversification occurring early in the Proterozoic can be seen to be unlikely on grounds of both parsimony and functional morphology. Indeed, the combination of the body and trace fossil record demonstrates a progressive diversification through the end of the Proterozoic well into the Cambrian and beyond, a picture consistent with body plans being assembled during this time. Body‐plan characters are likely to have been acquired monophyletically in the history of the bilaterians, and a model explaining the diversity in just one of them, the coelom, is presented. This analysis points to the requirement for a careful application of systematic methodology before explanations are sought for alleged patterns of constraint and flexibility.",
    url = "https://doi.org/10.1111/j.1469-185x.1999.tb00046.x",
    doi = "10.1111/j.1469-185x.1999.tb00046.x",
    openalex = "W4235889006",
    references = "doi101002aja1002030302, doi101002jmor1050540103, doi1010079781489928757, doi101017s0022336000024963, doi101038382127a0, doi101038387489a0, doi101098rstb19780005, doi101111j109600311991tb00045x, doi101111j146363951991tb00312x, doi101111j146363951995tb00988x, doi101111j146364091991tb00303x, doi101111j1469185x1988tb00631x, doi101111j150239311975tb01311x, doi101111j150239311998tb00509x, doi101126science16414901b, doi101126science28454232129, doi1023072530028, doi1023073223017, doi105860choice273873, doi105860choice295709, dzik1988the, openalexw2055967869, openalexw611184576"
}

@book{openalexw114509570,
    author = "Meyer, Christian A.",
    title = "Dinosaur Tracks and Other Fossil Footprints of Europe",
    year = "2000",
    openalex = "W114509570"
}

Patterns of bone microstructure have frequently been used to deduce dynamics and processes of growth in extant and fossil tetrapods. Often, the various types of primary bone tissue have been associated with different bone deposition rates and more recently such deductions have extended to patterns observed in dinosaur bone microstructure. These previous studies are challenged by the findings of the current research, which integrates an experimental neontological approach and a paleontological comparison. We use tetracycline labeling and morphometry to study the variability of bone deposition rates in Japanese quail (Coturnix japonica) growing under different experimental conditions. We compare resulting patterns in bone microstructure with those found in fossil birds and other dinosaurs. We found that a single type of primary bone varies significantly in rates of growth in response to environmental conditions. Ranging between 10-50 microm per day, rates of growth overlap with the full range of bone deposition rates that were previously associated with different patterns of bone histology. Bone formation rate was significantly affected by environmental/experimental conditions, skeletal element, and age. In the quail, the experimental conditions did not result in formation of lines of arrested growth (LAGs). Because of the observed variation of bone deposition rates in response to variation in environmental conditions, we conclude that bone deposition rates measured in extant birds cannot simply be extrapolated to their fossil relatives. Additionally, we observe the variable incidence of LAGs and annuli among several dinosaur species, including fossil birds, extant sauropsids, as well as nonmammalian synapsids, and some extant mammals. This suggests that the ancestral condition of the response of bone to environmental conditions was variable. We propose that such developmental plasticity in modern birds may be reduced in association with the shortened developmental time during the later evolution of the ornithurine birds.

@article{doi101002jmor10029,
    author = "Starck, J. Matthias and Chinsamy, Anusuya",
    title = "Bone microstructure and developmental plasticity in birds and other dinosaurs",
    year = "2002",
    journal = "Journal of Morphology",
    abstract = "Patterns of bone microstructure have frequently been used to deduce dynamics and processes of growth in extant and fossil tetrapods. Often, the various types of primary bone tissue have been associated with different bone deposition rates and more recently such deductions have extended to patterns observed in dinosaur bone microstructure. These previous studies are challenged by the findings of the current research, which integrates an experimental neontological approach and a paleontological comparison. We use tetracycline labeling and morphometry to study the variability of bone deposition rates in Japanese quail (Coturnix japonica) growing under different experimental conditions. We compare resulting patterns in bone microstructure with those found in fossil birds and other dinosaurs. We found that a single type of primary bone varies significantly in rates of growth in response to environmental conditions. Ranging between 10-50 microm per day, rates of growth overlap with the full range of bone deposition rates that were previously associated with different patterns of bone histology. Bone formation rate was significantly affected by environmental/experimental conditions, skeletal element, and age. In the quail, the experimental conditions did not result in formation of lines of arrested growth (LAGs). Because of the observed variation of bone deposition rates in response to variation in environmental conditions, we conclude that bone deposition rates measured in extant birds cannot simply be extrapolated to their fossil relatives. Additionally, we observe the variable incidence of LAGs and annuli among several dinosaur species, including fossil birds, extant sauropsids, as well as nonmammalian synapsids, and some extant mammals. This suggests that the ancestral condition of the response of bone to environmental conditions was variable. We propose that such developmental plasticity in modern birds may be reduced in association with the shortened developmental time during the later evolution of the ornithurine birds.",
    url = "https://doi.org/10.1002/jmor.10029",
    doi = "10.1002/jmor.10029",
    openalex = "W2064159002",
    references = "deklerk2000a, doi101016s0764446900001815, doi101017s0094837300013543, doi101017s0094837300021308, doi101038368196a0, doi10108002724634199310011490, doi101093clinids222240, doi101093oso97801951060840010001, doi1016660094837320000260466lhotts20co2, doi1016710272463420000200115lbhoth20co2, openalexw406909995"
}

@article{doi101016s003101820100459x,
    author = "Buatois, Luís A. and Mángano, M. Gabriela",
    title = "Trace fossils from Carboniferous floodplain deposits in western Argentina: implications for ichnofacies models of continental environments",
    year = "2002",
    journal = "Palaeogeography Palaeoclimatology Palaeoecology",
    url = "https://doi.org/10.1016/s0031-0182(01)00459-x",
    doi = "10.1016/s0031-0182(01)00459-x",
    openalex = "W2001601321",
    references = "doi1010079781489928757, doi10108010420949109386354, doi1016690883135120000150049itfaip20co2, doi1035767gscpgbull353333"
}

Paleontological research on predation has been expanding rapidly in scope, methods, and goals. The growing assortment of research strategies and goals has led to increasing differences in sampling strategies, types of data collected, definition of variables, and even reporting style. This methodological overview serves as a starting point for erecting some general methodological guidelines for studying the fossil record of predation. I focus here on trace fossils left by predators in the skeleton of their prey, arguably one of the most powerful sources of direct data on predator-prey interactions available in the fossil record. A critical survey of sampling protocols (data collecting strategy, sieve size, and sample size) and analytical approaches (predation intensity metrics, strategies for evaluating behavioral selectivity of predators, and taphonomic tests) reveals that various approaches can be fruitful depending on logistic circumstances and scientific goals of paleoecological projects. Despite numerous caveats and uncertainties, trace fossils left by predators on skeletons of their prey remain one of the most promising directions of research in paleoecology and evolutionary paleobiology.

@article{doi101017s1089332600001030,
    author = "Kowalewski, Michał",
    title = "The Fossil Record of Predation: An Overview of Analytical Methods",
    year = "2002",
    journal = "The Paleontological Society Papers",
    abstract = "Paleontological research on predation has been expanding rapidly in scope, methods, and goals. The growing assortment of research strategies and goals has led to increasing differences in sampling strategies, types of data collected, definition of variables, and even reporting style. This methodological overview serves as a starting point for erecting some general methodological guidelines for studying the fossil record of predation. I focus here on trace fossils left by predators in the skeleton of their prey, arguably one of the most powerful sources of direct data on predator-prey interactions available in the fossil record. A critical survey of sampling protocols (data collecting strategy, sieve size, and sample size) and analytical approaches (predation intensity metrics, strategies for evaluating behavioral selectivity of predators, and taphonomic tests) reveals that various approaches can be fruitful depending on logistic circumstances and scientific goals of paleoecological projects. Despite numerous caveats and uncertainties, trace fossils left by predators on skeletons of their prey remain one of the most promising directions of research in paleoecology and evolutionary paleobiology.",
    url = "https://doi.org/10.1017/s1089332600001030",
    doi = "10.1017/s1089332600001030",
    openalex = "W2886758028",
    references = "doi1010079781489928757, doi1010160195667182900416, doi101017s0022336000025567, doi101017s0094837300008174, doi101017s1089332600001133, doi101038337695c0, doi1011300091761319980261091afrfoh23co2, doi1012019781003077831, doi105479si00810266321, jacobsen1998feeding, openalexw1585246501"
}

The debate on avian ancestry: phylogeny, function, and fossils / Lawrence M. Witmer -- Cladistic approaches to the relationships of birds to other theropod dinosaurs / James M. Clark, Mark A. Norell and Peter J. Makovicky -- The enigmatic birdlike dinosaur Avimimus portentosus: comments and a pictorial atlas / Patricia Vickers-Rich, Luis M. Chiappe and Sergei Kurzanov -- The Cretaceous short-armed Alvarezsauridae: Mononykus and its kin / Luis M. Chiappe, Mark A. Norell and James M. Clark -- Alvarezsaurid relationships reconsidered / Fernando E. Novas and Diego Pol -- Archaeopterygidae (Upper Jurassic of Germany) / Andrzej Elzanowski -- The discovery and study of Mesozoic birds in China / Zhou Zhonghe and Hou Lianhai -- Sinornis santensis (Aves: Enantiornithes) from the early Cretaceous of northeastern China / Paul C. Sereno, Rao Chenggang and Li Jianjun -- The birds from the Lower Cretaceous of Las Hoyas (Province of Cuenca, Spain) / Jose L. Sanz... [et al.] -- Nogueromis gonzalezi (Aves: Ornithothoraces) from the early Cretaceous of Spain / Luis M. Chiappe and Antonio Lacasa-Ruiz -- Skeletal morphology and systematics of the Cretaceous Euenantiornithes (Ornithothoraces: Enantiornithes) / Luis M. Chiappe and Cyril A. Walker -- Vorona berivotrensis, a primitive bird from the late Cretaceous of Madagascar / Catherine A. Forster... [et al.] -- Osteology of the flightless Patagopteryx deferrariisi from the late Cretaceous of Patagonia (Argentina) / Luis M. Chiappe -- Enaliornis, an early Cretaceous hesperornithiform bird from England, with comments on other Hesperornithiformes / Peter M. Galton and Larry D. Martin -- The Mesozoic radiation of Neornithes / Sylvia Hope -- A review of avian Mesozoic fossil feathers / Alexander W.A. Kellner -- The track record of Mesozoic birds and pterosaurs: an ichnological and paleoecological perspective / Martin G. Lockley and Emma C. Rainforth -- Bone microstructure of early birds / Anusuya Chinsamy -- Locomotor evolution on the line to modern birds / Stephen M. Gatesy -- Basal bird phylogeny: problems and solutions / Luis M. Chiappe.

@article{doi1016660022336020030770822mbatho20co2,
    author = "Clarke, Julia",
    title = "Mesozoic Birds: Above the Heads of Dinosaurs",
    year = "2003",
    journal = "Journal of Paleontology",
    abstract = "The debate on avian ancestry: phylogeny, function, and fossils / Lawrence M. Witmer -- Cladistic approaches to the relationships of birds to other theropod dinosaurs / James M. Clark, Mark A. Norell and Peter J. Makovicky -- The enigmatic birdlike dinosaur Avimimus portentosus: comments and a pictorial atlas / Patricia Vickers-Rich, Luis M. Chiappe and Sergei Kurzanov -- The Cretaceous short-armed Alvarezsauridae: Mononykus and its kin / Luis M. Chiappe, Mark A. Norell and James M. Clark -- Alvarezsaurid relationships reconsidered / Fernando E. Novas and Diego Pol -- Archaeopterygidae (Upper Jurassic of Germany) / Andrzej Elzanowski -- The discovery and study of Mesozoic birds in China / Zhou Zhonghe and Hou Lianhai -- Sinornis santensis (Aves: Enantiornithes) from the early Cretaceous of northeastern China / Paul C. Sereno, Rao Chenggang and Li Jianjun -- The birds from the Lower Cretaceous of Las Hoyas (Province of Cuenca, Spain) / Jose L. Sanz... [et al.] -- Nogueromis gonzalezi (Aves: Ornithothoraces) from the early Cretaceous of Spain / Luis M. Chiappe and Antonio Lacasa-Ruiz -- Skeletal morphology and systematics of the Cretaceous Euenantiornithes (Ornithothoraces: Enantiornithes) / Luis M. Chiappe and Cyril A. Walker -- Vorona berivotrensis, a primitive bird from the late Cretaceous of Madagascar / Catherine A. Forster... [et al.] -- Osteology of the flightless Patagopteryx deferrariisi from the late Cretaceous of Patagonia (Argentina) / Luis M. Chiappe -- Enaliornis, an early Cretaceous hesperornithiform bird from England, with comments on other Hesperornithiformes / Peter M. Galton and Larry D. Martin -- The Mesozoic radiation of Neornithes / Sylvia Hope -- A review of avian Mesozoic fossil feathers / Alexander W.A. Kellner -- The track record of Mesozoic birds and pterosaurs: an ichnological and paleoecological perspective / Martin G. Lockley and Emma C. Rainforth -- Bone microstructure of early birds / Anusuya Chinsamy -- Locomotor evolution on the line to modern birds / Stephen M. Gatesy -- Basal bird phylogeny: problems and solutions / Luis M. Chiappe.",
    url = "https://doi.org/10.1666/0022-3360(2003)077<0822:mbatho>2.0.co;2",
    doi = "10.1666/0022-3360(2003)077<0822:mbatho>2.0.co;2",
    openalex = "W4301871956",
    references = "doi101038292051a0"
}

Preface Part I: The Archosaurian Heritage of Birds 1. The Debate on Avian Ancestry: Phylogeny, Function, and Fossils LAWRENCE M. WITMER 2. Cladistic Approaches to the Relationships of Birds to Other Theropod Dinosaurs JAMES M. CLARK, MARK A. NORELL, AND PETER J. MAKOVICKY Part II: Taxa of Controversial Status 3. The Enigmatic Birdlike Dinosaur Avimimus portentosus: Comments and a Pictorial Atlas PATRICIA VICKERS-RICH, LUIS M. CHIAPPE, AND SERGEI KURZANOV 4. The Cretaceous, Short-Armed Alvarezsauridae: Mononykus and Its Kin LUIS M. CHIAPPE, MARK A. NORELL, AND JAMES M. CLARK 5. Alvarezsaurid Relationships Reconsidered FERNANDO E. NOVAS AND DIEGO POL Part III: The Mesozoic Aviary: Anatomy and Systematics 6. Archaeopterygidae (Upper Jurassic of Germany) ANDRZEJ ELZANOWSKI 7. The Discovery and Study of Mesozoic Birds in China ZHOU ZHONGHE AND HOU LIANHAI 8. Sinornis santensis (Aves: Enantiornithes) from the Early Cretaceous of Northeastern China PAUL C. SERENO, RAO CHENGGANG, AND LI JIANJUN 9. The Birds from the Lower Cretaceous of Las Hoyas (Province of Cuenca, Spain) JOSE L. SANZ, BERNARDINO P. PEREZ-MORENO, LUIS M. CHIAPPE, AND ANGELA D. BUSCALIONI 10. Noguerornis gonzalezi (Aves) from the Early Cretaceous of Spain LUIS M. CHIAPPE AND ANTONIO LACASA-RUIZ 11. Skeletal Morphology and Systematics of the Cretaceous Euenantiornithes (Ornithothoraces: Enantiornithes) LUIS M. CHIAPPE AND CYRIL A. WALKER 12. Vorona berivotrensis, a Primitive Bird from the Late Cretaceous of Madagascar CATHERINE A. FORSTER, LUIS M. CHIAPPE, DAVID W. KRAUSE, AND SCOTT D. SAMPSON 13. Osteology of the Flightless Patagopteryx deferrariisi from the Late Cretaceous of Patagonia (Argentina) LUIS M. CHIAPPE 14. Enaliornis, an Early Cretaceous Hesperornithiform Bird from England, with Comments on other Hesperornithiformes PETER M. GALTON AND LARRY D. MARTIN 15. The Mesozoic Radiation of Neornithes SYLVIA HOPE 16. A Review of Avian Mesozoic Fossil Feathers ALEXANDER W. A. KELLNER 17. The Track Record of Mesozoic Birds and Pterosaurs: An Ichnological and Paleoecological Perspective MARTIN G. LOCKLEY AND EMMA C. RAINFORTH Part IV: Functional Morphology and Evolution 18. Bone Microstructure of Early Birds ANUSUYA CHINSAMY 19. Locomotor Evolution on the Line to Modern Birds STEPHEN M. GATESY 20. Basal Bird Phylogeny: Problems and Solutions LUIS M. CHIAPPE Contributors Index

@article{doi105860choice405235,
    title = "Mesozoic birds: above the heads of dinosaurs",
    year = "2003",
    journal = "Choice Reviews Online",
    abstract = "Preface Part I: The Archosaurian Heritage of Birds 1. The Debate on Avian Ancestry: Phylogeny, Function, and Fossils LAWRENCE M. WITMER 2. Cladistic Approaches to the Relationships of Birds to Other Theropod Dinosaurs JAMES M. CLARK, MARK A. NORELL, AND PETER J. MAKOVICKY Part II: Taxa of Controversial Status 3. The Enigmatic Birdlike Dinosaur Avimimus portentosus: Comments and a Pictorial Atlas PATRICIA VICKERS-RICH, LUIS M. CHIAPPE, AND SERGEI KURZANOV 4. The Cretaceous, Short-Armed Alvarezsauridae: Mononykus and Its Kin LUIS M. CHIAPPE, MARK A. NORELL, AND JAMES M. CLARK 5. Alvarezsaurid Relationships Reconsidered FERNANDO E. NOVAS AND DIEGO POL Part III: The Mesozoic Aviary: Anatomy and Systematics 6. Archaeopterygidae (Upper Jurassic of Germany) ANDRZEJ ELZANOWSKI 7. The Discovery and Study of Mesozoic Birds in China ZHOU ZHONGHE AND HOU LIANHAI 8. Sinornis santensis (Aves: Enantiornithes) from the Early Cretaceous of Northeastern China PAUL C. SERENO, RAO CHENGGANG, AND LI JIANJUN 9. The Birds from the Lower Cretaceous of Las Hoyas (Province of Cuenca, Spain) JOSE L. SANZ, BERNARDINO P. PEREZ-MORENO, LUIS M. CHIAPPE, AND ANGELA D. BUSCALIONI 10. Noguerornis gonzalezi (Aves) from the Early Cretaceous of Spain LUIS M. CHIAPPE AND ANTONIO LACASA-RUIZ 11. Skeletal Morphology and Systematics of the Cretaceous Euenantiornithes (Ornithothoraces: Enantiornithes) LUIS M. CHIAPPE AND CYRIL A. WALKER 12. Vorona berivotrensis, a Primitive Bird from the Late Cretaceous of Madagascar CATHERINE A. FORSTER, LUIS M. CHIAPPE, DAVID W. KRAUSE, AND SCOTT D. SAMPSON 13. Osteology of the Flightless Patagopteryx deferrariisi from the Late Cretaceous of Patagonia (Argentina) LUIS M. CHIAPPE 14. Enaliornis, an Early Cretaceous Hesperornithiform Bird from England, with Comments on other Hesperornithiformes PETER M. GALTON AND LARRY D. MARTIN 15. The Mesozoic Radiation of Neornithes SYLVIA HOPE 16. A Review of Avian Mesozoic Fossil Feathers ALEXANDER W. A. KELLNER 17. The Track Record of Mesozoic Birds and Pterosaurs: An Ichnological and Paleoecological Perspective MARTIN G. LOCKLEY AND EMMA C. RAINFORTH Part IV: Functional Morphology and Evolution 18. Bone Microstructure of Early Birds ANUSUYA CHINSAMY 19. Locomotor Evolution on the Line to Modern Birds STEPHEN M. GATESY 20. Basal Bird Phylogeny: Problems and Solutions LUIS M. CHIAPPE Contributors Index",
    url = "https://doi.org/10.5860/choice.40-5235",
    doi = "10.5860/choice.40-5235",
    openalex = "W586262331",
    references = "doi101038nature01342, doi101093auk11941187"
}

ABSTRACT Histological evidence of the bones of pterosaurs and dinosaurs indicates that the typically large forms of these groups grew at rates more comparable to those of birds and mammals than to those of other living reptiles. However, Scutellosaurus, a small, bipedal, basal thyreophoran ornithischian dinosaur of the Early Jurassic, shows histological features in its skeletal tissues that suggest relatively lower growth rates than in those of larger dinosaurs. In these respects Scutellosaurus, like other small dinosaurs such as Orodromeus and some basal birds, is more like young, rapidly growing crocodiles than larger, more derived ornithischians (hadrosaurs) and all saurischians (sauropods and theropods). Similar patterns can be seen in small, mostly basal pterosaurs such as Eudimorphodon and Rhamphorhynchus. However, superficial similarities to crocodile bone growth belie some important differences, which are most usefully interpreted in phylogenetic and ontogenetic contexts. Large size evolved secondarily in several dinosaurian and pterosaurian lineages. We hypothesize that this larger size was made possible by rapid growth strategies that are reflected by characteristic highly vascularized fibro-lamellar bone tissues that comprise most of the cortex. Dinosaurs and pterosaurs, like other tetrapodes, generally grew more quickly in early stages and more slowly as growth neared completion. As in other vertebrate groups, taxa of small adult size may have grown at lower rates or for shorter durations than larger taxa did. Phylogenetic patterns suggest that by themselves, the low vascularity and inferred low growth rates seen in small dinosaurs and pterosaurs are not good indicators of thermometabolic regime, because they are correlated so strongly with size. They may reflect mechanical exigencies of small size rather than especially lower growth rates, tied to the process of deposition of particular kinds of bone tissues. The evolution of life history strategies in dinosaurs and pterosaurs, as they relate to rates of growth and adult body sizes, will be better understood as more complete histological studies place these data into phylogenetic and ontogenetic contexts.

@article{doi1016710272463420040240555gisdap20co2,
    author = "Padian, Kevin and Horner, John R. and de Ricqlès, Armand",
    title = "Growth in small dinosaurs and pterosaurs: the evolution of archosaurian growth strategies",
    year = "2004",
    journal = "Journal of Vertebrate Paleontology",
    abstract = "ABSTRACT Histological evidence of the bones of pterosaurs and dinosaurs indicates that the typically large forms of these groups grew at rates more comparable to those of birds and mammals than to those of other living reptiles. However, Scutellosaurus, a small, bipedal, basal thyreophoran ornithischian dinosaur of the Early Jurassic, shows histological features in its skeletal tissues that suggest relatively lower growth rates than in those of larger dinosaurs. In these respects Scutellosaurus, like other small dinosaurs such as Orodromeus and some basal birds, is more like young, rapidly growing crocodiles than larger, more derived ornithischians (hadrosaurs) and all saurischians (sauropods and theropods). Similar patterns can be seen in small, mostly basal pterosaurs such as Eudimorphodon and Rhamphorhynchus. However, superficial similarities to crocodile bone growth belie some important differences, which are most usefully interpreted in phylogenetic and ontogenetic contexts. Large size evolved secondarily in several dinosaurian and pterosaurian lineages. We hypothesize that this larger size was made possible by rapid growth strategies that are reflected by characteristic highly vascularized fibro-lamellar bone tissues that comprise most of the cortex. Dinosaurs and pterosaurs, like other tetrapodes, generally grew more quickly in early stages and more slowly as growth neared completion. As in other vertebrate groups, taxa of small adult size may have grown at lower rates or for shorter durations than larger taxa did. Phylogenetic patterns suggest that by themselves, the low vascularity and inferred low growth rates seen in small dinosaurs and pterosaurs are not good indicators of thermometabolic regime, because they are correlated so strongly with size. They may reflect mechanical exigencies of small size rather than especially lower growth rates, tied to the process of deposition of particular kinds of bone tissues. The evolution of life history strategies in dinosaurs and pterosaurs, as they relate to rates of growth and adult body sizes, will be better understood as more complete histological studies place these data into phylogenetic and ontogenetic contexts.",
    url = "https://doi.org/10.1671/0272-4634(2004)024[0555:gisdap]2.0.co;2",
    doi = "10.1671/0272-4634(2004)024[0555:gisdap]2.0.co;2",
    openalex = "W2176430550",
    references = "crossref1998encyclopedia, doi101007bf02118752, doi101016s0764446900001815, doi101016s1631069102014294, doi101017s0094837300021308, doi101038282296a0, doi10108002724634199310011490, doi101093clinids222240, doi101093oso97801951060840010001, doi101111j109636422000tb02201x, doi1015159781400853724, doi1016660094837320000260466lhotts20co2, doi1016660094837320010270039coosea20co2, doi1016660094837320030290105dbttoo20co2, doi1016710272463420000200115lbhoth20co2, doi1023071444685, doi1023073514751, openalexw225597919, openalexw2607033038, openalexw563887495, vitt1982the"
}

@article{doi101038nature03150,
    author = "Clarke, Julia A. and Tambussi, Claudia P. and Noriega, Jorge I. and Erickson, Gregory M. and Ketcham, Richard A.",
    title = "Definitive fossil evidence for the extant avian radiation in the Cretaceous",
    year = "2005",
    journal = "Nature",
    url = "https://doi.org/10.1038/nature03150",
    doi = "10.1038/nature03150",
    openalex = "W2073925386",
    references = "doi101006mpev19980603, doi101016s0098300400001163, doi101017s0025315400028575, doi101038122881a0, doi10103835086500, doi101038381226a0, doi101098rspb20001368, doi101098rspb20011877, doi101111j109600312003tb00387x, doi101126science27553031109, doi1012060003008220023870001tmappo20co2, doi1016660022336020030770822mbatho20co2, doi105860choice405235"
}

The taxonomic treatment of trace fossils needs a uniform approach, independent of the ethologic groups concerned. To this aim, trace fossils are rigorously defined with regard to biological taxa and physical sedimentary structures. Potential ichnotaxobases are evaluated, with morphology resulting as the most important criterion. For trace fossils related to bioerosion and herbivory, substrate plays a key role, as well as composition for coprolites. Size, producer, age, facies and preservation are rejected as ichnotaxobases. Separate names for undertracks and other poorly preserved material should gradually be replaced by ichnotaxa based on well-preserved specimens. Recent traces may be identified using established trace fossil taxa but new names can only be based on fossil material, even if the distinction between recent and fossil may frequently remain arbitrary. It is stressed that ichnotaxa must not be incorporated into biological taxa in systematics. Composite trace fossil structures (complex structures made by the combined activity of two or more species) have no ichnotaxonomic standing but compound traces (complex structures made by one individual tracemaker) may be named separately under certain provisions. The following emendations are proposed to the International Code of Zoological Nomenclature: The term ‘work of an animal’ should be deleted from the code, and ichnotaxa should be based solely on trace fossils as defined herein.

@article{doi10108000241160600787890,
    author = "Bertling, Markus and Braddy, Simon J. and Bromley, Richard G. and Demathieu, Georges and Genise, Jorge F. and Mikuláš, Radek and Nielsen, Jan Kresten and Nielsen, Kurt Søren Svensson and Rindsberg, Andrew K. and Schlirf, Michael and Uchman, Alfred",
    title = "Names for trace fossils: a uniform approach",
    year = "2006",
    journal = "Lethaia",
    abstract = "The taxonomic treatment of trace fossils needs a uniform approach, independent of the ethologic groups concerned. To this aim, trace fossils are rigorously defined with regard to biological taxa and physical sedimentary structures. Potential ichnotaxobases are evaluated, with morphology resulting as the most important criterion. For trace fossils related to bioerosion and herbivory, substrate plays a key role, as well as composition for coprolites. Size, producer, age, facies and preservation are rejected as ichnotaxobases. Separate names for undertracks and other poorly preserved material should gradually be replaced by ichnotaxa based on well-preserved specimens. Recent traces may be identified using established trace fossil taxa but new names can only be based on fossil material, even if the distinction between recent and fossil may frequently remain arbitrary. It is stressed that ichnotaxa must not be incorporated into biological taxa in systematics. Composite trace fossil structures (complex structures made by the combined activity of two or more species) have no ichnotaxonomic standing but compound traces (complex structures made by one individual tracemaker) may be named separately under certain provisions. The following emendations are proposed to the International Code of Zoological Nomenclature: The term ‘work of an animal’ should be deleted from the code, and ichnotaxa should be based solely on trace fossils as defined herein.",
    url = "https://doi.org/10.1080/00241160600787890",
    doi = "10.1080/00241160600787890",
    openalex = "W2029068730",
    references = "doi101007978140203609529, doi1010079781489928757, doi101007978364265923210, doi1010160012825272900724, doi10108010420949409386386, doi101111j136531211991tb00851x, doi101144gslsp20042280106, doi105860choice322751, openalexw1494869040, openalexw2108311936, openalexw2344228935, openalexw384818744, openalexw560158229"
}

This beautifully illustrated 2007 volume describes the entire flora and fauna of the famous Lower Cretaceous Crato Formation of Brazil - one of the world's most important fossil deposits, exhibiting exceptional preservation. A wide range of invertebrates and vertebrates are covered, including extended sections on pterosaurs and insects. Two chapters are devoted to plants. Many of the chapters include descriptions of new species and re-descriptions and appraisals of taxa published in obscure places, rendering them available to a wider audience. Fossil descriptions are supported by detailed explanations of the geological history of the deposit and its tectonic setting. Drawing on expertise from around the world and specimens from the most important museum collections, this book forms an essential reference for researchers and enthusiasts with an interest in Mesozoic fossils

@book{doi101017cbo9780511535512,
    author = "Martill, David M. and Bechly, Günter and Loveridge, Robert F.",
    title = "The Crato Fossil Beds of Brazil: Window into an Ancient World",
    year = "2007",
    abstract = "This beautifully illustrated 2007 volume describes the entire flora and fauna of the famous Lower Cretaceous Crato Formation of Brazil - one of the world's most important fossil deposits, exhibiting exceptional preservation. A wide range of invertebrates and vertebrates are covered, including extended sections on pterosaurs and insects. Two chapters are devoted to plants. Many of the chapters include descriptions of new species and re-descriptions and appraisals of taxa published in obscure places, rendering them available to a wider audience. Fossil descriptions are supported by detailed explanations of the geological history of the deposit and its tectonic setting. Drawing on expertise from around the world and specimens from the most important museum collections, this book forms an essential reference for researchers and enthusiasts with an interest in Mesozoic fossils",
    url = "https://doi.org/10.1017/cbo9780511535512",
    doi = "10.1017/cbo9780511535512",
    openalex = "W1575411947",
    references = "doi101002mmng20010040112, doi1010079783642143977, doi1010160031018279901639, doi101016s0031018203006436, doi101017s0094837300012331, doi10103821872, doi101038292051a0, doi10103831635, doi101038nature01342, doi101038nature01420, doi101038nature02855, doi101038nature03150, doi101038nature03996, doi101046j1365202820010270ex, doi10108002724634199810011114, doi10108002724634199910011201, doi101098rspb20042692, doi101126science23547931156, doi101126science27953581915, doi1012060003009020062970001tatol20co2, doi1016660022336020040780989dapftc20co2, doi1018590euscorpius2003vol2003iss111, doi1023071466954, doi1023073223017, doi10560219780801847806, doi105860choice405235, doi105962bhltitle4275, hasiotis1995termite, openalexw1486025919, openalexw1725516486, openalexw1900040508, openalexw193970361, openalexw2242001249, openalexw2786463731"
}

A fossil discovery in the mid-Cretaceous Blackleaf Formation of southwest Montana, USA, has yielded the first trace and body fossil evidence of burrowing behaviour in a dinosaur. Skeletal remains of an adult and two juveniles of Oryctodromeus cubicularis gen. et sp. nov. a new species of hypsilophodont-grade dinosaur, were found in the expanded distal chamber of a sediment-filled burrow. Correspondence between burrow and adult dimensions supports Oryctodromeus as the burrow maker. Additionally, Oryctodromeus exhibits features of the snout, shoulder girdle and pelvis consistent with digging habits while retaining cursorial hindlimb proportions. Association of adult and young within a terminal chamber provides definitive evidence of extensive parental care in the Dinosauria. As with modern vertebrate cursors that dig, burrowing in Oryctodromeus may have been an important adaptation for the rearing of young. Burrowing also represents a mechanism by which small dinosaurs may have exploited the extreme environments of polar latitudes, deserts and high mountain areas. The ability among dinosaurs to find or make shelter may contradict some scenarios of the Cretaceous-Paleogene impact event. Burrowing habits expand the known range of nonavian dinosaur behaviours and suggest that the cursorial ancestry of dinosaurs did not fully preclude the evolution of different functional regimes, such as fossoriality.

@article{doi101098rspb20060443,
    author = "Varricchio, David J. and Martin, Anthony J. and Katsura, Yoshihiro",
    title = "First trace and body fossil evidence of a burrowing, denning dinosaur",
    year = "2007",
    journal = "Proceedings of the Royal Society B Biological Sciences",
    abstract = "A fossil discovery in the mid-Cretaceous Blackleaf Formation of southwest Montana, USA, has yielded the first trace and body fossil evidence of burrowing behaviour in a dinosaur. Skeletal remains of an adult and two juveniles of Oryctodromeus cubicularis gen. et sp. nov. a new species of hypsilophodont-grade dinosaur, were found in the expanded distal chamber of a sediment-filled burrow. Correspondence between burrow and adult dimensions supports Oryctodromeus as the burrow maker. Additionally, Oryctodromeus exhibits features of the snout, shoulder girdle and pelvis consistent with digging habits while retaining cursorial hindlimb proportions. Association of adult and young within a terminal chamber provides definitive evidence of extensive parental care in the Dinosauria. As with modern vertebrate cursors that dig, burrowing in Oryctodromeus may have been an important adaptation for the rearing of young. Burrowing also represents a mechanism by which small dinosaurs may have exploited the extreme environments of polar latitudes, deserts and high mountain areas. The ability among dinosaurs to find or make shelter may contradict some scenarios of the Cretaceous-Paleogene impact event. Burrowing habits expand the known range of nonavian dinosaur behaviours and suggest that the cursorial ancestry of dinosaurs did not fully preclude the evolution of different functional regimes, such as fossoriality.",
    url = "https://doi.org/10.1098/rspb.2006.0443",
    doi = "10.1098/rspb.2006.0443",
    openalex = "W2159630773",
    references = "doi101038282296a0, doi101038385247a0, doi101126science28454232137, doi1011300016760619931050129cop23co2, doi101130spe216p1, doi101353book59141, doi1016710272463420040240555gisdap20co2, doi102307622963, openalexw1968568170, openalexw1996683265, openalexw225597919, openalexw2603335639"
}

Fossils of the Early Cretaceous dinosaur, Nigersaurus taqueti, document for the first time the cranial anatomy of a rebbachisaurid sauropod. Its extreme adaptations for herbivory at ground-level challenge current hypotheses regarding feeding function and feeding strategy among diplodocoids, the larger clade of sauropods that includes Nigersaurus. We used high resolution computed tomography, stereolithography, and standard molding and casting techniques to reassemble the extremely fragile skull. Computed tomography also allowed us to render the first endocast for a sauropod preserving portions of the olfactory bulbs, cerebrum and inner ear, the latter permitting us to establish habitual head posture. To elucidate evidence of tooth wear and tooth replacement rate, we used photographic-casting techniques and crown thin sections, respectively. To reconstruct its 9-meter postcranial skeleton, we combined and size-adjusted multiple partial skeletons. Finally, we used maximum parsimony algorithms on character data to obtain the best estimate of phylogenetic relationships among diplodocoid sauropods. Nigersaurus taqueti shows extreme adaptations for a dinosaurian herbivore including a skull of extremely light construction, tooth batteries located at the distal end of the jaws, tooth replacement as fast as one per month, an expanded muzzle that faces directly toward the ground, and hollow presacral vertebral centra with more air sac space than bone by volume. A cranial endocast provides the first reasonably complete view of a sauropod brain including its small olfactory bulbs and cerebrum. Skeletal and dental evidence suggests that Nigersaurus was a ground-level herbivore that gathered and sliced relatively soft vegetation, the culmination of a low-browsing feeding strategy first established among diplodocoids during the Jurassic.

@article{doi101371journalpone0001230,
    author = "Sereno, Paul C. and Wilson, Jeffrey A. and Witmer, Lawrence M. and Whitlock, John A. and Maga, Abdoulaye and Idé, Oumarou and Rowe, Timothy A.",
    title = "Structural Extremes in a Cretaceous Dinosaur",
    year = "2007",
    journal = "PLoS ONE",
    abstract = "Fossils of the Early Cretaceous dinosaur, Nigersaurus taqueti, document for the first time the cranial anatomy of a rebbachisaurid sauropod. Its extreme adaptations for herbivory at ground-level challenge current hypotheses regarding feeding function and feeding strategy among diplodocoids, the larger clade of sauropods that includes Nigersaurus. We used high resolution computed tomography, stereolithography, and standard molding and casting techniques to reassemble the extremely fragile skull. Computed tomography also allowed us to render the first endocast for a sauropod preserving portions of the olfactory bulbs, cerebrum and inner ear, the latter permitting us to establish habitual head posture. To elucidate evidence of tooth wear and tooth replacement rate, we used photographic-casting techniques and crown thin sections, respectively. To reconstruct its 9-meter postcranial skeleton, we combined and size-adjusted multiple partial skeletons. Finally, we used maximum parsimony algorithms on character data to obtain the best estimate of phylogenetic relationships among diplodocoid sauropods. Nigersaurus taqueti shows extreme adaptations for a dinosaurian herbivore including a skull of extremely light construction, tooth batteries located at the distal end of the jaws, tooth replacement as fast as one per month, an expanded muzzle that faces directly toward the ground, and hollow presacral vertebral centra with more air sac space than bone by volume. A cranial endocast provides the first reasonably complete view of a sauropod brain including its small olfactory bulbs and cerebrum. Skeletal and dental evidence suggests that Nigersaurus was a ground-level herbivore that gathered and sliced relatively soft vegetation, the culmination of a low-browsing feeding strategy first established among diplodocoids during the Jurassic.",
    url = "https://doi.org/10.1371/journal.pone.0001230",
    doi = "10.1371/journal.pone.0001230",
    openalex = "W2111030938",
    references = "doi10100797844317693306, doi101017cbo9780511536045, doi101017s0094837300007557, doi101038274661a0, doi101038nature02048, doi101046j10963642200200029x, doi101073pnas932514623, doi10108002724634199810011115, doi101126science1118806, doi101525california97805202462320010001, doi105860choice260307, doi105962bhltitle102117, doi105962bhltitle60562, doi105962p234818, larsson2000forebrain, openalexw2983381470, openalexw2989049194"
}

This study concerns the formation, taphonomy, and preservation of human footprints in microbial mats of present-day tidal-flat environments. Due to differences in water content and nature of the microbial mats and the underlying sediment, a wide range of footprint morphologies was produced by the same trackmaker. Most true tracks are subjected to modification due to taphonomic processes, leading to modified true tracks. In addition to formation of biolaminites, microbial mats play a major role in the preservation of footprints on tidal flats. A footprint may be consolidated by desiccation or lithification of the mat, or by ongoing growth of the mat. The latter process may lead to the formation of overtracks. Among consolidated or (partially) lithified footprints found on present-day tidal flats, poorly defined true tracks, modified true tracks, and overtracks were most frequently encountered while unmodified and well-defined true tracks are rather rare. We suggest that modified true tracks and overtracks make up an important percentage of fossil footprints and that they may be as common as undertracks. However, making unambiguous distinctions between poorly defined true tracks, modified true tracks, undertracks, and overtracks in the fossil record will remain a difficult task, which necessitates systematic excavation of footprints combined with careful analysis of the encasing sediment.

@article{doi10108010420940802471027,
    author = "Marty, Daniel and Strasser, André and Meyer, Christian A.",
    title = "Formation and Taphonomy of Human Footprints in Microbial Mats of Present-Day Tidal-flat Environments: Implications for the Study of Fossil Footprints",
    year = "2009",
    journal = "Ichnos/Ichnos : an international journal for plant and animal traces",
    abstract = "This study concerns the formation, taphonomy, and preservation of human footprints in microbial mats of present-day tidal-flat environments. Due to differences in water content and nature of the microbial mats and the underlying sediment, a wide range of footprint morphologies was produced by the same trackmaker. Most true tracks are subjected to modification due to taphonomic processes, leading to modified true tracks. In addition to formation of biolaminites, microbial mats play a major role in the preservation of footprints on tidal flats. A footprint may be consolidated by desiccation or lithification of the mat, or by ongoing growth of the mat. The latter process may lead to the formation of overtracks. Among consolidated or (partially) lithified footprints found on present-day tidal flats, poorly defined true tracks, modified true tracks, and overtracks were most frequently encountered while unmodified and well-defined true tracks are rather rare. We suggest that modified true tracks and overtracks make up an important percentage of fossil footprints and that they may be as common as undertracks. However, making unambiguous distinctions between poorly defined true tracks, modified true tracks, undertracks, and overtracks in the fossil record will remain a difficult task, which necessitates systematic excavation of footprints combined with careful analysis of the encasing sediment.",
    url = "https://doi.org/10.1080/10420940802471027",
    doi = "10.1080/10420940802471027",
    openalex = "W2103008101",
    references = "doi1010079789400904095, doi101016jtim200507008, doi10103820167, doi101046j13653091200000284x, doi101111j13653091200400649x, doi101144gslsp20042280106, doi1023073514674, doi1023073514964, doi1023073514973, doi105860choice273305, doi105860choice295709, doi105860choice332752, doi105860choice393984, doi107312lock90868, openalexw114509570, openalexw39955589, openalexw603337959"
}

The oldest unequivocal records of Dinosauria were unearthed from Late Triassic rocks (approximately 230 Ma) accumulated over extensional rift basins in southwestern Pangea. The better known of these are Herrerasaurus ischigualastensis, Pisanosaurus mertii, Eoraptor lunensis, and Panphagia protos from the Ischigualasto Formation, Argentina, and Staurikosaurus pricei and Saturnalia tupiniquim from the Santa Maria Formation, Brazil. No uncontroversial dinosaur body fossils are known from older strata, but the Middle Triassic origin of the lineage may be inferred from both the footprint record and its sister-group relation to Ladinian basal dinosauromorphs. These include the typical Marasuchus lilloensis, more basal forms such as Lagerpeton and Dromomeron, as well as silesaurids: a possibly monophyletic group composed of Mid-Late Triassic forms that may represent immediate sister taxa to dinosaurs. The first phylogenetic definition to fit the current understanding of Dinosauria as a node-based taxon solely composed of mutually exclusive Saurischia and Ornithischia was given as "all descendants of the most recent common ancestor of birds and Triceratops". Recent cladistic analyses of early dinosaurs agree that Pisanosaurus mertii is a basal ornithischian; that Herrerasaurus ischigualastensis and Staurikosaurus pricei belong in a monophyletic Herrerasauridae; that herrerasaurids, Eoraptor lunensis, and Guaibasaurus candelariensis are saurischians; that Saurischia includes two main groups, Sauropodomorpha and Theropoda; and that Saturnalia tupiniquim is a basal member of the sauropodomorph lineage. On the contrary, several aspects of basal dinosaur phylogeny remain controversial, including the position of herrerasaurids, E. lunensis, and G. candelariensis as basal theropods or basal saurischians, and the affinity and/or validity of more fragmentary taxa such as Agnosphitys cromhallensis, Alwalkeria maleriensis, Chindesaurus bryansmalli, Saltopus elginensis, and Spondylosoma absconditum. The identification of dinosaur apomorphies is jeopardized by the incompleteness of skeletal remains attributed to most basal dinosauromorphs, the skulls and forelimbs of which are particularly poorly known. Nonetheless, Dinosauria can be diagnosed by a suite of derived traits, most of which are related to the anatomy of the pelvic girdle and limb. Some of these are connected to the acquisition of a fully erect bipedal gait, which has been traditionally suggested to represent a key adaptation that allowed, or even promoted, dinosaur radiation during Late Triassic times. Yet, contrary to the classical "competitive" models, dinosaurs did not gradually replace other terrestrial tetrapods over the Late Triassic. In fact, the radiation of the group comprises at least three landmark moments, separated by controversial (Carnian-Norian, Triassic-Jurassic) extinction events. These are mainly characterized by early diversification in Carnian times, a Norian increase in diversity and (especially) abundance, and the occupation of new niches from the Early Jurassic onwards. Dinosaurs arose from fully bipedal ancestors, the diet of which may have been carnivorous or omnivorous. Whereas the oldest dinosaurs were geographically restricted to south Pangea, including rare ornithischians and more abundant basal members of the saurischian lineage, the group achieved a nearly global distribution by the latest Triassic, especially with the radiation of saurischian groups such as "prosauropods" and coelophysoids.

@article{doi101111j1469185x200900094x,
    author = "Langer, Max C. and Ezcurra, Martín D. and Bittencourt, Jonathas S. and Novas, Fernando E.",
    title = "The origin and early evolution of dinosaurs",
    year = "2009",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    abstract = {The oldest unequivocal records of Dinosauria were unearthed from Late Triassic rocks (approximately 230 Ma) accumulated over extensional rift basins in southwestern Pangea. The better known of these are Herrerasaurus ischigualastensis, Pisanosaurus mertii, Eoraptor lunensis, and Panphagia protos from the Ischigualasto Formation, Argentina, and Staurikosaurus pricei and Saturnalia tupiniquim from the Santa Maria Formation, Brazil. No uncontroversial dinosaur body fossils are known from older strata, but the Middle Triassic origin of the lineage may be inferred from both the footprint record and its sister-group relation to Ladinian basal dinosauromorphs. These include the typical Marasuchus lilloensis, more basal forms such as Lagerpeton and Dromomeron, as well as silesaurids: a possibly monophyletic group composed of Mid-Late Triassic forms that may represent immediate sister taxa to dinosaurs. The first phylogenetic definition to fit the current understanding of Dinosauria as a node-based taxon solely composed of mutually exclusive Saurischia and Ornithischia was given as "all descendants of the most recent common ancestor of birds and Triceratops". Recent cladistic analyses of early dinosaurs agree that Pisanosaurus mertii is a basal ornithischian; that Herrerasaurus ischigualastensis and Staurikosaurus pricei belong in a monophyletic Herrerasauridae; that herrerasaurids, Eoraptor lunensis, and Guaibasaurus candelariensis are saurischians; that Saurischia includes two main groups, Sauropodomorpha and Theropoda; and that Saturnalia tupiniquim is a basal member of the sauropodomorph lineage. On the contrary, several aspects of basal dinosaur phylogeny remain controversial, including the position of herrerasaurids, E. lunensis, and G. candelariensis as basal theropods or basal saurischians, and the affinity and/or validity of more fragmentary taxa such as Agnosphitys cromhallensis, Alwalkeria maleriensis, Chindesaurus bryansmalli, Saltopus elginensis, and Spondylosoma absconditum. The identification of dinosaur apomorphies is jeopardized by the incompleteness of skeletal remains attributed to most basal dinosauromorphs, the skulls and forelimbs of which are particularly poorly known. Nonetheless, Dinosauria can be diagnosed by a suite of derived traits, most of which are related to the anatomy of the pelvic girdle and limb. Some of these are connected to the acquisition of a fully erect bipedal gait, which has been traditionally suggested to represent a key adaptation that allowed, or even promoted, dinosaur radiation during Late Triassic times. Yet, contrary to the classical "competitive" models, dinosaurs did not gradually replace other terrestrial tetrapods over the Late Triassic. In fact, the radiation of the group comprises at least three landmark moments, separated by controversial (Carnian-Norian, Triassic-Jurassic) extinction events. These are mainly characterized by early diversification in Carnian times, a Norian increase in diversity and (especially) abundance, and the occupation of new niches from the Early Jurassic onwards. Dinosaurs arose from fully bipedal ancestors, the diet of which may have been carnivorous or omnivorous. Whereas the oldest dinosaurs were geographically restricted to south Pangea, including rare ornithischians and more abundant basal members of the saurischian lineage, the group achieved a nearly global distribution by the latest Triassic, especially with the radiation of saurischian groups such as "prosauropods" and coelophysoids.},
    url = "https://doi.org/10.1111/j.1469-185x.2009.00094.x",
    doi = "10.1111/j.1469-185x.2009.00094.x",
    openalex = "W2121596487",
    references = "chatterjee2013a, crossref1998encyclopedia, currie2009stratigraphy, doi1010160031018281900924, doi1010160031018295000178, doi101016c20090644421, doi101016jjsames200504002, doi101016jpalaeo200606041, doi101016s0012825203000825, doi101016s0016699580800386, doi101016s0016699583800205, doi101016s0031018298001175, doi101017cbo9780511628948, doi101017s0094837300010575, doi101017s1477201906001970, doi101017s1477201907002040, doi101017s1477201907002246, doi101017s1477201907002271, doi101017s247526300000091x, doi10103820167, doi10106313060577, doi101073pnas0606028103, doi10108002724634199410011538, doi10108002724634199510011271, doi10108002724634199810011115, doi10108002724634199910011124, doi101098rspb20042692, doi101098rspb20080715, doi101098rspl18870117, doi101098rstb19990489, doi101111j109636421985tb01796x, doi101111j10963642200400130x, doi101126science1143325, doi101126science21545391501, doi101126science2645160828, doi101126science2845414616, doi101126science3616622, doi101127njgpa210199841, doi101144gsjgs14720321, doi1012060003009020073021taoeoa20co2, doi101525california97805202420980010001, doi1015468gbdyof, doi1016710272463420020220510toomka20co2, doi1016710272463420072773tclagn20co2, doi101671a1097, doi1023071292217, doi1023071441916, doi1023073889325, doi102475ajss319111253, doi102475ajss32313381, doi104202app20080415, doi10432497802030907329, doi105281zenodo16120887, doi105281zenodo16171435, doi105281zenodo16246150, doi105860choice325663, doi105860choice393984, doi105860choice465038, doi107146moggeosciv32i140904, doi10718895fylantbak30809522, openalexw114509570, openalexw1496509561, openalexw1535663436, openalexw205674743, openalexw2242116350, openalexw2788234611, openalexw2991310333, openalexw3208547338, openalexw3215057009, padian1989presence, rowe1989a, walker1964triassic"
}

Sauropod dinosaur bones are common in Mesozoic terrestrial sediments, but sauropod skulls are exceedingly rare--cranial materials are known for less than one third of sauropod genera and even fewer are known from complete skulls. Here we describe the first complete sauropod skull from the Cretaceous of the Americas, Abydosaurus mcintoshi, n. gen., n. sp., known from 104.46 +/- 0.95 Ma (megannum) sediments from Dinosaur National Monument, USA. Abydosaurus shares close ancestry with Brachiosaurus, which appeared in the fossil record ca. 45 million years earlier and had substantially broader teeth. A survey of tooth shape in sauropodomorphs demonstrates that sauropods evolved broad crowns during the Early Jurassic but did not evolve narrow crowns until the Late Jurassic, when they occupied their greatest range of crown breadths. During the Cretaceous, brachiosaurids and other lineages independently underwent a marked diminution in tooth breadth, and before the latest Cretaceous broad-crowned sauropods were extinct on all continental landmasses. Differential survival and diversification of narrow-crowned sauropods in the Late Cretaceous appears to be a directed trend that was not correlated with changes in plant diversity or abundance, but may signal a shift towards elevated tooth replacement rates and high-wear dentition. Sauropods lacked many of the complex herbivorous adaptations present within contemporaneous ornithischian herbivores, such as beaks, cheeks, kinesis, and heterodonty. The spartan design of sauropod skulls may be related to their remarkably small size--sauropod skulls account for only 1/200th of total body volume compared to 1/30th body volume in ornithopod dinosaurs.

@article{doi101007s0011401006506,
    author = "Chure, Daniel J. and Britt, Brooks B. and Whitlock, John A. and Wilson, Jeffrey A.",
    title = "First complete sauropod dinosaur skull from the Cretaceous of the Americas and the evolution of sauropod dentition",
    year = "2010",
    journal = "Die Naturwissenschaften",
    abstract = "Sauropod dinosaur bones are common in Mesozoic terrestrial sediments, but sauropod skulls are exceedingly rare--cranial materials are known for less than one third of sauropod genera and even fewer are known from complete skulls. Here we describe the first complete sauropod skull from the Cretaceous of the Americas, Abydosaurus mcintoshi, n. gen., n. sp., known from 104.46 +/- 0.95 Ma (megannum) sediments from Dinosaur National Monument, USA. Abydosaurus shares close ancestry with Brachiosaurus, which appeared in the fossil record ca. 45 million years earlier and had substantially broader teeth. A survey of tooth shape in sauropodomorphs demonstrates that sauropods evolved broad crowns during the Early Jurassic but did not evolve narrow crowns until the Late Jurassic, when they occupied their greatest range of crown breadths. During the Cretaceous, brachiosaurids and other lineages independently underwent a marked diminution in tooth breadth, and before the latest Cretaceous broad-crowned sauropods were extinct on all continental landmasses. Differential survival and diversification of narrow-crowned sauropods in the Late Cretaceous appears to be a directed trend that was not correlated with changes in plant diversity or abundance, but may signal a shift towards elevated tooth replacement rates and high-wear dentition. Sauropods lacked many of the complex herbivorous adaptations present within contemporaneous ornithischian herbivores, such as beaks, cheeks, kinesis, and heterodonty. The spartan design of sauropod skulls may be related to their remarkably small size--sauropod skulls account for only 1/200th of total body volume compared to 1/30th body volume in ornithopod dinosaurs.",
    url = "https://doi.org/10.1007/s00114-010-0650-6",
    doi = "10.1007/s00114-010-0650-6",
    openalex = "W1989949799",
    references = "doi101073pnas932514623, doi101371journalpone0001230, doi101371journalpone0006924, doi101525california97805202420980030015, doi105860choice435907"
}

It has often been assumed that Australasian Cretaceous dinosaur faunas were for the most part endemic, but with some Laurasian affinities. In this regard, some Australasian dinosaurs have been considered Jurassic relicts, while others were thought to represent typical Laurasian forms or endemic taxa. Furthermore, it has been proposed that some dinosaurian lineages, namely oviraptorosaurians, dromaeosaurids, ornithomimosaurians and protoceratopsians, may have originated in Australia before dispersing to Asia during the Early Cretaceous. Here we provide a detailed review of Cretaceous non-avian dinosaurs from Australia and New Zealand, and compare them with taxa from other Gondwanan landmasses. Our results challenge the traditional view of Australian dinosaur faunas, with the majority of taxa displaying affinities that are concordant with current palaeobiogeographic models of Gondwanan terrestrial vertebrate faunal distribution. We reinterpret putative Australian ‘hypsilophodontids’ as basal ornithopods (some of them probably related to South American forms), and the recently described protoceratopsians are referred to Genasauria indet. and Ornithopoda indet. Among Theropoda, the Australian pigmy ‘Allosaurus’ is referred to the typical Gondwanan clade Abelisauroidea. Similarities are also observed between the enigmatic Australian theropod Rapator, Australovenator and the South American carcharodontosaurian Megaraptor. Timimus and putative oviraptorosaurians are referred to Dromaeosauridae. The present revision demonstrates that Australia's non-avian Cretaceous dinosaurian faunas were reminiscent of those found in other, roughly contemporaneous, Gondwanan landmasses, and are suggestive of faunal interchange with these regions via Antarctica.

@article{doi10108014772011003594870,
    author = "Agnolín, Federico L. and Ezcurra, Martín D. and Pais, Diego F. and Salisbury, Steven W.",
    title = "A reappraisal of the Cretaceous non-avian dinosaur faunas from Australia and New Zealand: evidence for their Gondwanan affinities",
    year = "2010",
    journal = "Journal of Systematic Palaeontology",
    abstract = "It has often been assumed that Australasian Cretaceous dinosaur faunas were for the most part endemic, but with some Laurasian affinities. In this regard, some Australasian dinosaurs have been considered Jurassic relicts, while others were thought to represent typical Laurasian forms or endemic taxa. Furthermore, it has been proposed that some dinosaurian lineages, namely oviraptorosaurians, dromaeosaurids, ornithomimosaurians and protoceratopsians, may have originated in Australia before dispersing to Asia during the Early Cretaceous. Here we provide a detailed review of Cretaceous non-avian dinosaurs from Australia and New Zealand, and compare them with taxa from other Gondwanan landmasses. Our results challenge the traditional view of Australian dinosaur faunas, with the majority of taxa displaying affinities that are concordant with current palaeobiogeographic models of Gondwanan terrestrial vertebrate faunal distribution. We reinterpret putative Australian ‘hypsilophodontids’ as basal ornithopods (some of them probably related to South American forms), and the recently described protoceratopsians are referred to Genasauria indet. and Ornithopoda indet. Among Theropoda, the Australian pigmy ‘Allosaurus’ is referred to the typical Gondwanan clade Abelisauroidea. Similarities are also observed between the enigmatic Australian theropod Rapator, Australovenator and the South American carcharodontosaurian Megaraptor. Timimus and putative oviraptorosaurians are referred to Dromaeosauridae. The present revision demonstrates that Australia's non-avian Cretaceous dinosaurian faunas were reminiscent of those found in other, roughly contemporaneous, Gondwanan landmasses, and are suggestive of faunal interchange with these regions via Antarctica.",
    url = "https://doi.org/10.1080/14772011003594870",
    doi = "10.1080/14772011003594870",
    openalex = "W2151988812",
    references = "chinsamy1998polar, crossref1998encyclopedia, deklerk2000a, doi101017s0016756804000330, doi10108002724634198510011859, doi10108002724634199510011230, doi101093oxfordjournalsafrafa101747, doi101098rspb20060443, doi101126science10246376, doi101126science11282807, doi101126science24248841403, doi101126science28454232137, doi105281zenodo16171435, doi105281zenodo16673433, doi105281zenodo16692311, doi105860choice331556, doi105860choice353642, doi107312kiel11918, openalexw1821824396, openalexw1879660213, openalexw2173200745, openalexw597685939, openalexw616953834"
}

BACKGROUND: The theropod dinosaur family Troodontidae is known from the Upper Jurassic, Lower Cretaceous, and Upper Cretaceous of Asia and from the Upper Jurassic and Upper Cretaceous of North America. Before now no undisputed troodontids from North America have been reported from the Early Cretaceous. METHODOLOGY/PRINCIPAL FINDINGS: Herein we describe a theropod maxilla from the Lower Cretaceous Cedar Mountain Formation of Utah and perform a phylogenetic analysis to determine its phylogenetic position. The specimen is distinctive enough to assign to a new genus and species, Geminiraptor suarezarum. Phylogenetic analysis places G. suarezarum within Troodontidae in an unresolved polytomy with Mei, Byronosaurus, Sinornithoides, Sinusonasus, and Troodon+(Saurornithoides+Zanabazar). Geminiraptor suarezarum uniquely exhibits extreme pneumatic inflation of the maxilla internal to the antorbital fossa such that the anterior maxilla has a triangular cross-section. Unlike troodontids more closely related to Troodon, G. suarezarum exhibits bony septa between the dental alveoli and a promaxillary foramen that is visible in lateral view. CONCLUSIONS/SIGNIFICANCE: This is the first report of a North American troodontid from the Lower Cretaceous. It therefore contributes to a fuller understanding of troodontid biogeography through time. It also adds to the known dinosaurian fauna of the Cedar Mountain Formation.

@article{doi101371journalpone0014329,
    author = "Senter, Phil and Kirkland, James I and Bird, John and Bartlett, Jeff A",
    title = "A new troodontid theropod dinosaur from the lower Cretaceous of Utah.",
    year = "2010",
    journal = "PloS one",
    abstract = "BACKGROUND: The theropod dinosaur family Troodontidae is known from the Upper Jurassic, Lower Cretaceous, and Upper Cretaceous of Asia and from the Upper Jurassic and Upper Cretaceous of North America. Before now no undisputed troodontids from North America have been reported from the Early Cretaceous. METHODOLOGY/PRINCIPAL FINDINGS: Herein we describe a theropod maxilla from the Lower Cretaceous Cedar Mountain Formation of Utah and perform a phylogenetic analysis to determine its phylogenetic position. The specimen is distinctive enough to assign to a new genus and species, Geminiraptor suarezarum. Phylogenetic analysis places G. suarezarum within Troodontidae in an unresolved polytomy with Mei, Byronosaurus, Sinornithoides, Sinusonasus, and Troodon+(Saurornithoides+Zanabazar). Geminiraptor suarezarum uniquely exhibits extreme pneumatic inflation of the maxilla internal to the antorbital fossa such that the anterior maxilla has a triangular cross-section. Unlike troodontids more closely related to Troodon, G. suarezarum exhibits bony septa between the dental alveoli and a promaxillary foramen that is visible in lateral view. CONCLUSIONS/SIGNIFICANCE: This is the first report of a North American troodontid from the Lower Cretaceous. It therefore contributes to a fuller understanding of troodontid biogeography through time. It also adds to the known dinosaurian fauna of the Cedar Mountain Formation.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC3002269/",
    doi = "10.1371/journal.pone.0014329",
    openalex = "W2071617171",
    pmcid = "PMC3002269",
    pmid = "21179513",
    references = "doi101038nature02898, doi101038nature03996, doi101038nature08322, doi10108002724634199710011027, doi101098rspl18870117, doi101126science13234331023, doi102475ajss31695411, doi102475ajss319111253, openalexw3215057009, openalexw3217097258"
}

This success stems mainly from the intimate connection of ichnology with sedimentology and the importance of both fields for paleoenvironmental and basin analysis, which becomes more and more important in petroleum exploration. This useful connection, however, also had its price. In the hand of biogeologists, trace fossils easily lose their significance as unique biological documents.Dolf Seilacher Trace Fossil Analysis (2007)

@incollection{doi101017cbo9780511975622004,
    author = "Buatois, Luís A. and Mángano, M. Gabriela",
    title = "Paleobiology of trace fossils",
    year = "2011",
    booktitle = "Cambridge University Press eBooks",
    abstract = "This success stems mainly from the intimate connection of ichnology with sedimentology and the importance of both fields for paleoenvironmental and basin analysis, which becomes more and more important in petroleum exploration. This useful connection, however, also had its price. In the hand of biogeologists, trace fossils easily lose their significance as unique biological documents.Dolf Seilacher Trace Fossil Analysis (2007)",
    url = "https://doi.org/10.1017/cbo9780511975622.004",
    doi = "10.1017/cbo9780511975622.004",
    openalex = "W2276570023"
}

The correlation between large body size and digestive efficiency has been hypothesized to have driven trends of increasing mass in herbivorous clades by means of directional selection. Yet, to date, few studies have investigated this relationship from a phylogenetic perspective, and none, to our knowledge, with regard to trophic shifts. Here, we reconstruct body mass in the three major subclades of non-avian theropod dinosaurs whose ecomorphology is correlated with extrinsic evidence of at least facultative herbivory in the fossil record--all of which also achieve relative gigantism (more than 3000 kg). Ordinary least-squares regressions on natural log-transformed mean mass recover significant correlations between increasing mass and geological time. However, tests for directional evolution in body mass find no support for a phylogenetic trend, instead favouring passive models of trait evolution. Cross-correlation of sympatric taxa from five localities in Asia reveals that environmental influences such as differential habitat sampling and/or taphonomic filtering affect the preserved record of dinosaurian body mass in the Cretaceous. Our results are congruent with studies documenting that behavioural and/or ecological factors may mitigate the benefit of increasing mass in extant taxa, and suggest that the hypothesis can be extrapolated to herbivorous lineages across geological time scales.

@article{doi101098rspb20122526,
    author = "Zanno, Lindsay E and Makovicky, Peter J",
    title = "No evidence for directional evolution of body mass in herbivorous theropod dinosaurs.",
    year = "2013",
    journal = "Proceedings. Biological sciences",
    abstract = "The correlation between large body size and digestive efficiency has been hypothesized to have driven trends of increasing mass in herbivorous clades by means of directional selection. Yet, to date, few studies have investigated this relationship from a phylogenetic perspective, and none, to our knowledge, with regard to trophic shifts. Here, we reconstruct body mass in the three major subclades of non-avian theropod dinosaurs whose ecomorphology is correlated with extrinsic evidence of at least facultative herbivory in the fossil record--all of which also achieve relative gigantism (more than 3000 kg). Ordinary least-squares regressions on natural log-transformed mean mass recover significant correlations between increasing mass and geological time. However, tests for directional evolution in body mass find no support for a phylogenetic trend, instead favouring passive models of trait evolution. Cross-correlation of sympatric taxa from five localities in Asia reveals that environmental influences such as differential habitat sampling and/or taphonomic filtering affect the preserved record of dinosaurian body mass in the Cretaceous. Our results are congruent with studies documenting that behavioural and/or ecological factors may mitigate the benefit of increasing mass in extant taxa, and suggest that the hypothesis can be extrapolated to herbivorous lineages across geological time scales.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC3574415/",
    doi = "10.1098/rspb.2012.2526",
    openalex = "W2161039338",
    pmcid = "PMC3574415",
    pmid = "23193135",
    references = "doi101017cbo9780511565441, doi10103831635, doi10103844766, doi101038nclimate1259, doi101111j001438202003tb00285x, doi101111j146364091997tb00423x, doi1023072285423, openalexw2183707334, openalexw3206657856"
}

Dinosaur remains from the Arabian subcontinent are exceedingly rare, and those that have been documented manifest indeterminate affinities. Consequently the discovery of a small, but diagnostic, accumulation of elements from Campanian-Maastrichtian (\textasciitilde\ 75 Ma) deposits in northwestern Saudi Arabia is significant because it constitutes the first taxonomically identifiable dinosaur material described from the Arabian Peninsula. The fossils include a series of possible lithostrotian titanosaur caudal vertebrae, and some isolated theropod marginal teeth that share unique character states and metric parameters (analyzed using multivariate statistical methods) with derived abelisaurids - this is the first justifiable example of a non-avian carnivorous dinosaur clade from Arabia. The recognition of titanosaurians and abelisaurids from Saudi Arabia extends the palaeogeographical range of these groups along the entire northern Gondwanan margin during the latest Cretaceous. Moreover, given the extreme paucity of coeval occurrences elsewhere, the Saudi Arabian fossils provide a tantalizing glimpse into dinosaurian assemblage diversity within the region.

@article{doi101371journalpone0084041,
    author = "Kear, Benjamin P and Rich, Thomas H and Vickers-Rich, Patricia and Ali, Mohammed A and Al-Mufarreh, Yahya A and Matari, Adel H and Al-Massari, Abdu M and Nasser, Abdulaziz H and Attia, Yousry and Halawani, Mohammed A",
    title = "First dinosaurs from Saudi Arabia.",
    year = "2013",
    journal = "PloS one",
    abstract = "Dinosaur remains from the Arabian subcontinent are exceedingly rare, and those that have been documented manifest indeterminate affinities. Consequently the discovery of a small, but diagnostic, accumulation of elements from Campanian-Maastrichtian (\textasciitilde\ 75 Ma) deposits in northwestern Saudi Arabia is significant because it constitutes the first taxonomically identifiable dinosaur material described from the Arabian Peninsula. The fossils include a series of possible lithostrotian titanosaur caudal vertebrae, and some isolated theropod marginal teeth that share unique character states and metric parameters (analyzed using multivariate statistical methods) with derived abelisaurids - this is the first justifiable example of a non-avian carnivorous dinosaur clade from Arabia. The recognition of titanosaurians and abelisaurids from Saudi Arabia extends the palaeogeographical range of these groups along the entire northern Gondwanan margin during the latest Cretaceous. Moreover, given the extreme paucity of coeval occurrences elsewhere, the Saudi Arabian fossils provide a tantalizing glimpse into dinosaurian assemblage diversity within the region.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC3873419/",
    doi = "10.1371/journal.pone.0084041",
    openalex = "W1972546011",
    pmcid = "PMC3873419",
    pmid = "24386326",
    references = "doi1010029780470750711, doi101017cbo9780511608377011, doi101017s1477201907002246, doi101046j10963642200200029x, doi101111j10963642201200853x, doi1012067481, doi101525california97805202420980010001, doi1016710272463420020220510toomka20co2, openalexw2183707334, openalexw581267017"
}

Historical biogeography has been characterized by a large diversity of methods and unresolved debates about which processes, such as dispersal or vicariance, are most important for explaining distributions. A new R package, BioGeoBEARS, implements many models in a common likelihood framework, so that standard statistical model selection procedures can be applied to let the data choose the best model. Available models include a likelihood version of DIVA (“DIVALIKE”), LAGRANGE’s DEC model, and BAYAREA, as well as “+J” versions of these models which include founder-event speciation, an important process left out of most inference methods. I use BioGeoBEARS on a large sample of island and non-island clades (including two fossil clades) to show that founder-event speciation is a crucial process in almost every clade, and that most published datasets reject the non-J models currently in widespread use. BioGeoBEARS is open-source and freely available for installation at the Comprehensive R Archive Network at http://CRAN.R-project.org/package=BioGeoBEARS. A step-by-step tutorial is available at http://phylo.wikidot.com/biogeobears.

@article{doi1021425f55419694,
    author = "Matzke, Nicholas J.",
    title = "Probabilistic historical biogeography: new models for founder-event speciation, imperfect detection, and fossils allow improved accuracy and model-testing",
    year = "2013",
    journal = "Frontiers of Biogeography",
    abstract = "Historical biogeography has been characterized by a large diversity of methods and unresolved debates about which processes, such as dispersal or vicariance, are most important for explaining distributions. A new R package, BioGeoBEARS, implements many models in a common likelihood framework, so that standard statistical model selection procedures can be applied to let the data choose the best model. Available models include a likelihood version of DIVA (“DIVALIKE”), LAGRANGE’s DEC model, and BAYAREA, as well as “+J” versions of these models which include founder-event speciation, an important process left out of most inference methods. I use BioGeoBEARS on a large sample of island and non-island clades (including two fossil clades) to show that founder-event speciation is a crucial process in almost every clade, and that most published datasets reject the non-J models currently in widespread use. BioGeoBEARS is open-source and freely available for installation at the Comprehensive R Archive Network at http://CRAN.R-project.org/package=BioGeoBEARS. A step-by-step tutorial is available at http://phylo.wikidot.com/biogeobears.",
    url = "https://doi.org/10.21425/f55419694",
    doi = "10.21425/f55419694",
    openalex = "W4239710195",
    references = "doi101002bies20745, doi101016jtree201108009, doi101093bioinformatics149817, doi101093sysbiosyt040, doi101111j13652699200501383x, doi101111j15585646201201730x, doi101146annurevecolsys102209144710, doi1021425f55419694, doi1023073514444, doi1023073802723, openalexw1527551209"
}

Birds are among the most diverse and intensively studied vertebrate groups, but many aspects of their higher-level phylogeny and evolution still remain controversial. One contentious issue concerns the antiquity of modern birds (=crown Aves): the age of the most recent common ancestor of all living birds (Gauthier 1986). Very few Mesozoic fossils are attributable to modern birds (e.g., Clarke et al. 2005; Dyke and Kaiser 2011; Brocklehurst et al. 2012; Ksepka and Boyd 2012) suggesting that they diversified largely or entirely in the early Paleogene, perhaps in the ecological vacuum created by the extinction of non-avian dinosaurs, pterosaurs, and many archaic (stem) birds (e.g., Longrich et al. 2011). In contrast, molecular studies indicate that modern birds commenced radiating deep within the Mesozoic, for example ∼130 Ma (Cooper and Penny 1997; Haddrath and Baker 2012) or ∼113 Ma (Jetz et al. 2012), with ratites, galliforms, anseriforms, shorebirds, and even passerines surviving across the KPg boundary (∼66 Ma). The oldest molecular dates further imply an extraordinarily rapid early bird evolution, with the modern birds appearing only 20 myr after Archaeopteryx (∼150 Ma). However, both approaches entail considerable uncertainties: for example, nonpreservation of fossils always underestimates the antiquity of lineages, whereas rate heterogeneity, saturation, and calibration uncertainty can strongly bias molecular divergence dating.

@article{doi101093sysbiosyt110,
    author = "Lee, Minho and Cau, Andrea and Naish, Darren and Dyke, Gareth J.",
    title = "Morphological Clocks in Paleontology, and a Mid-Cretaceous Origin of Crown Aves",
    year = "2014",
    journal = "Systematic Biology",
    abstract = "Birds are among the most diverse and intensively studied vertebrate groups, but many aspects of their higher-level phylogeny and evolution still remain controversial. One contentious issue concerns the antiquity of modern birds (=crown Aves): the age of the most recent common ancestor of all living birds (Gauthier 1986). Very few Mesozoic fossils are attributable to modern birds (e.g., Clarke et al. 2005; Dyke and Kaiser 2011; Brocklehurst et al. 2012; Ksepka and Boyd 2012) suggesting that they diversified largely or entirely in the early Paleogene, perhaps in the ecological vacuum created by the extinction of non-avian dinosaurs, pterosaurs, and many archaic (stem) birds (e.g., Longrich et al. 2011). In contrast, molecular studies indicate that modern birds commenced radiating deep within the Mesozoic, for example ∼130 Ma (Cooper and Penny 1997; Haddrath and Baker 2012) or ∼113 Ma (Jetz et al. 2012), with ratites, galliforms, anseriforms, shorebirds, and even passerines surviving across the KPg boundary (∼66 Ma). The oldest molecular dates further imply an extraordinarily rapid early bird evolution, with the modern birds appearing only 20 myr after Archaeopteryx (∼150 Ma). However, both approaches entail considerable uncertainties: for example, nonpreservation of fossils always underestimates the antiquity of lineages, whereas rate heterogeneity, saturation, and calibration uncertainty can strongly bias molecular divergence dating.",
    url = "https://doi.org/10.1093/sysbio/syt110",
    doi = "10.1093/sysbio/syt110",
    openalex = "W2141865835",
    references = "doi101038nature12168"
}

Abstract Between the M iddle J urassic and H olocene, birds evolved an enormous diversity of behaviours. The distribution and antiquity of these behaviours is difficult to establish given a relatively poor fossil record. Rare crop, stomach and gut contents typically reveal diets consistent with morphology but stem‐members of some lineages (including C ariamae and C oraciiformes) seem to have been different in ecology from their extant relatives. Most of our ideas about the behaviour of fossil birds are based on analogy (with skull form, limb proportions and claw curvature being used to guide hypotheses). However, this has limitations given that some extinct taxa lack extant analogues and that some extant taxa do not behave as predicted by osteology. Reductionist methods have been used to test predation style and running ability in fossil taxa including moa, G astornis and phorusrhacids. Virtually nothing is known of nesting and nest‐building behaviour but colonial nesting is known from the C retaceous onwards. Rare vegetative nests demonstrate modern nest‐building from the E ocene onwards. Ornamental rectrices indicate that sexually driven display drove some aspects of feather evolution and evidence for loud vocal behaviour and intraspecific combat is known for some taxa. Our knowledge of fossil bird behaviour indicates that ‘modern’ behaviours are at least as old as crown birds. Stem‐members of extant lineages, however, may sometimes or often have differed from extant taxa.

@article{doi101111jzo12113,
    author = "Naish, Darren",
    title = "The fossil record of bird behaviour",
    year = "2014",
    journal = "Journal of Zoology",
    abstract = "Abstract Between the M iddle J urassic and H olocene, birds evolved an enormous diversity of behaviours. The distribution and antiquity of these behaviours is difficult to establish given a relatively poor fossil record. Rare crop, stomach and gut contents typically reveal diets consistent with morphology but stem‐members of some lineages (including C ariamae and C oraciiformes) seem to have been different in ecology from their extant relatives. Most of our ideas about the behaviour of fossil birds are based on analogy (with skull form, limb proportions and claw curvature being used to guide hypotheses). However, this has limitations given that some extinct taxa lack extant analogues and that some extant taxa do not behave as predicted by osteology. Reductionist methods have been used to test predation style and running ability in fossil taxa including moa, G astornis and phorusrhacids. Virtually nothing is known of nesting and nest‐building behaviour but colonial nesting is known from the C retaceous onwards. Rare vegetative nests demonstrate modern nest‐building from the E ocene onwards. Ornamental rectrices indicate that sexually driven display drove some aspects of feather evolution and evidence for loud vocal behaviour and intraspecific combat is known for some taxa. Our knowledge of fossil bird behaviour indicates that ‘modern’ behaviours are at least as old as crown birds. Stem‐members of extant lineages, however, may sometimes or often have differed from extant taxa.",
    url = "https://doi.org/10.1111/jzo.12113",
    doi = "10.1111/jzo.12113",
    openalex = "W2113579774",
    references = "doi1010079783030876456, doi101007s0011401209171, doi101016s014019631831231x, doi101017s0094837300006564, doi101038nature00930, doi101073pnas1011924108, doi101080027246342012719176, doi101093icb302251, doi101098rspb19980308, doi101111j15023931201100300x, doi101146annurevento48091801112725, doi1023073889096, openalexw114509570, witmer1991biomechanics"
}

Recent discoveries have highlighted the dramatic evolutionary transformation of massive, ground-dwelling theropod dinosaurs into light, volant birds. Here, we apply Bayesian approaches (originally developed for inferring geographic spread and rates of molecular evolution in viruses) in a different context: to infer size changes and rates of anatomical innovation (across up to 1549 skeletal characters) in fossils. These approaches identify two drivers underlying the dinosaur-bird transition. The theropod lineage directly ancestral to birds undergoes sustained miniaturization across 50 million years and at least 12 consecutive branches (internodes) and evolves skeletal adaptations four times faster than other dinosaurs. The distinct, prolonged phase of miniaturization along the bird stem would have facilitated the evolution of many novelties associated with small body size, such as reorientation of body mass, increased aerial ability, and paedomorphic skulls with reduced snouts but enlarged eyes and brains.

@article{doi101126science1252243,
    author = "Lee, Michael S. Y. and Cau, Andrea and Naish, Darren and Dyke, Gareth J.",
    title = "Sustained miniaturization and anatomical innovation in the dinosaurian ancestors of birds",
    year = "2014",
    journal = "Science",
    abstract = "Recent discoveries have highlighted the dramatic evolutionary transformation of massive, ground-dwelling theropod dinosaurs into light, volant birds. Here, we apply Bayesian approaches (originally developed for inferring geographic spread and rates of molecular evolution in viruses) in a different context: to infer size changes and rates of anatomical innovation (across up to 1549 skeletal characters) in fossils. These approaches identify two drivers underlying the dinosaur-bird transition. The theropod lineage directly ancestral to birds undergoes sustained miniaturization across 50 million years and at least 12 consecutive branches (internodes) and evolves skeletal adaptations four times faster than other dinosaurs. The distinct, prolonged phase of miniaturization along the bird stem would have facilitated the evolution of many novelties associated with small body size, such as reorientation of body mass, increased aerial ability, and paedomorphic skulls with reduced snouts but enlarged eyes and brains.",
    url = "https://doi.org/10.1126/science.1252243",
    doi = "10.1126/science.1252243",
    openalex = "W2068703220",
    references = "christiansen2004mass, doi101016jearscirev201004001, doi101038nature10906, doi101038nature11146, doi101038nature12168, doi101073pnas1203238109, doi10108001621459199510476572, doi101080106351501753462876, doi101080147720192010484650, doi101080147720192011630927, doi101093bioinformaticsbtm388, doi101093molbevmss075, doi101093oxfordjournalsmolbeva003872, doi101093sysbiosys029, doi101098rspb20122526, doi101111evo12150, doi101111j10963642200900591x, doi101111j1469185x200900094x, doi101126science1193304, doi101126science1225376, doi101126science1228753, doi101371journalpbio0040088, doi101371journalpbio1001853, doi1022179revmacn14372, doi102307409735, doi105281zenodo16171435, nesbitt2013the, openalexw2611511275, rauhut2003a"
}

Phylogeny-based approaches can be used to infer diversification dynamics and the rate and pattern of trait change. Applying these analyses to fossil data often requires time-scaling a cladogram of morphotaxon relationships. Although several time-scaling methods have been developed for this purpose, the incomplete sampling of the fossil record can distort the apparent timing of branching. It is unclear how well different time-scaling methods reconstruct the true temporal relationships or how any such inaccuracy could affect tree-based evolutionary analyses. I developed process-based simulations of the fossil record that allow the comparison of approximated time-scaled trees to true time-scaled trees. I used this simulation framework to test the effect of time-scaling methods on the fidelity of several commonly applied tree-based analyses, across a range of simulation conditions. When the fidelity of time-scaling methods differed, the stochastic “ cal3” time-scaling method with ancestral assignment produced preferable results. Estimating rates and models of continuous trait evolution was particularly sensitive to bias from scenarios that forced the insertion of many short branch lengths, a bias that is not solved by any of the considered time-scaling methods in all scenarios. The cal3 method of time-scaling can be recommended as the preferred time-scaling method among those tested, but caution must be exercised because tree-based analyses are prone to easily overlooked biases.

@article{doi10166613033,
    author = "Bapst, David W.",
    title = "Assessing the effect of time-scaling methods on phylogeny-based analyses in the fossil record",
    year = "2014",
    journal = "Paleobiology",
    abstract = "Phylogeny-based approaches can be used to infer diversification dynamics and the rate and pattern of trait change. Applying these analyses to fossil data often requires time-scaling a cladogram of morphotaxon relationships. Although several time-scaling methods have been developed for this purpose, the incomplete sampling of the fossil record can distort the apparent timing of branching. It is unclear how well different time-scaling methods reconstruct the true temporal relationships or how any such inaccuracy could affect tree-based evolutionary analyses. I developed process-based simulations of the fossil record that allow the comparison of approximated time-scaled trees to true time-scaled trees. I used this simulation framework to test the effect of time-scaling methods on the fidelity of several commonly applied tree-based analyses, across a range of simulation conditions. When the fidelity of time-scaling methods differed, the stochastic “ cal3” time-scaling method with ancestral assignment produced preferable results. Estimating rates and models of continuous trait evolution was particularly sensitive to bias from scenarios that forced the insertion of many short branch lengths, a bias that is not solved by any of the considered time-scaling methods in all scenarios. The cal3 method of time-scaling can be recommended as the preferred time-scaling method among those tested, but caution must be exercised because tree-based analyses are prone to easily overlooked biases.",
    url = "https://doi.org/10.1666/13033",
    doi = "10.1666/13033",
    openalex = "W2121539896",
    references = "doi101098rspb20122526, doi101111j15585646201101447x, doi101371journalpone0031838"
}

@article{doi101038nature19852,
    author = "Clarke, Julia A. and Chatterjee, Sankar and Li, Zhiheng and Riede, Tobias and Agnolín, Federico L. and Goller, Franz and Isasi, Marcelo P. and Martinioni, Daniel R. and Mussel, Francisco J. and Novas, Fernando E.",
    title = "Fossil evidence of the avian vocal organ from the Mesozoic",
    year = "2016",
    journal = "Nature",
    url = "https://doi.org/10.1038/nature19852",
    doi = "10.1038/nature19852",
    openalex = "W2531572791",
    references = "doi101080027246342014912656, doi101126science1253293"
}

Relationships between non-avian theropod dinosaurs and extant and fossil birds are a major focus of current paleobiological research. Despite extensive phylogenetic and morphological support, behavioural evidence is mostly ambiguous and does not usually fossilize. Thus, inferences that dinosaurs, especially theropods displayed behaviour analogous to modern birds are intriguing but speculative. Here we present extensive and geographically widespread physical evidence of substrate scraping behavior by large theropods considered as compelling evidence of "display arenas" or leks, and consistent with "nest scrape display" behaviour among many extant ground-nesting birds. Large scrapes, up to 2 m in diameter, occur abundantly at several Cretaceous sites in Colorado. They constitute a previously unknown category of large dinosaurian trace fossil, inferred to fill gaps in our understanding of early phases in the breeding cycle of theropods. The trace makers were probably lekking species that were seasonally active at large display arena sites. Such scrapes indicate stereotypical avian behaviour hitherto unknown among Cretaceous theropods, and most likely associated with terrirorial activity in the breeding season. The scrapes most probably occur near nesting colonies, as yet unknown or no longer preserved in the immediate study areas. Thus, they provide clues to paleoenvironments where such nesting sites occurred.

@article{doi101038srep18952,
    author = "Lockley, Martin G and McCrea, Richard T and Buckley, Lisa G and Lim, Jong Deock and Matthews, Neffra A and Breithaupt, Brent H and Houck, Karen J and Gierliński, Gerard D and Surmik, Dawid and Kim, Kyung Soo and Xing, Lida and Kong, Dal Yong and Cart, Ken and Martin, Jason and Hadden, Glade",
    title = "Theropod courtship: large scale physical evidence of display arenas and avian-like scrape ceremony behaviour by Cretaceous dinosaurs.",
    year = "2016",
    journal = "Scientific reports",
    abstract = {Relationships between non-avian theropod dinosaurs and extant and fossil birds are a major focus of current paleobiological research. Despite extensive phylogenetic and morphological support, behavioural evidence is mostly ambiguous and does not usually fossilize. Thus, inferences that dinosaurs, especially theropods displayed behaviour analogous to modern birds are intriguing but speculative. Here we present extensive and geographically widespread physical evidence of substrate scraping behavior by large theropods considered as compelling evidence of "display arenas" or leks, and consistent with "nest scrape display" behaviour among many extant ground-nesting birds. Large scrapes, up to 2 m in diameter, occur abundantly at several Cretaceous sites in Colorado. They constitute a previously unknown category of large dinosaurian trace fossil, inferred to fill gaps in our understanding of early phases in the breeding cycle of theropods. The trace makers were probably lekking species that were seasonally active at large display arena sites. Such scrapes indicate stereotypical avian behaviour hitherto unknown among Cretaceous theropods, and most likely associated with terrirorial activity in the breeding season. The scrapes most probably occur near nesting colonies, as yet unknown or no longer preserved in the immediate study areas. Thus, they provide clues to paleoenvironments where such nesting sites occurred.},
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC4704466/",
    doi = "10.1038/srep18952",
    openalex = "W2436312931",
    pmcid = "PMC4704466",
    pmid = "26741567",
    references = "doi1010079781489928757, doi1010079789400904095, doi101038nature02898, doi101038nature12168, doi101098rspb20060443, doi101111j15023931201100300x, doi101126science1253293, doi101126science27953581915, openalexw1550095290, sereno1997the"
}

Compared with all other living reptiles, birds grow extremely fast and possess unusually low levels of intraspecific variation during postnatal development. It is now clear that birds inherited their high rates of growth from their dinosaurian ancestors, but the origin of the avian condition of low variation during development is poorly constrained. The most well-understood growth trajectories of later Mesozoic theropods (e.g., Tyrannosaurus, Allosaurus) show similarly low variation to birds, contrasting with higher variation in extant crocodylians. Here, we show that deep within Dinosauria, among the earliest-diverging dinosaurs, anomalously high intraspecific variation is widespread but then is lost in more derived theropods. This style of development is ancestral for dinosaurs and their closest relatives, and, surprisingly, this level of variation is far higher than in living crocodylians. Among early dinosaurs, this variation is widespread across Pangaea in the Triassic and Early Jurassic, and among early-diverging theropods (ceratosaurs), this variation is maintained for 165 million years to the end of the Cretaceous. Because the Late Triassic environment across Pangaea was volatile and heterogeneous, this variation may have contributed to the rise of dinosaurian dominance through the end of the Triassic Period.

@article{doi101073pnas1613813113,
    author = "Griffin, Christopher T and Nesbitt, Sterling J",
    title = "Anomalously high variation in postnatal development is ancestral for dinosaurs but lost in birds.",
    year = "2016",
    journal = "Proceedings of the National Academy of Sciences of the United States of America",
    abstract = "Compared with all other living reptiles, birds grow extremely fast and possess unusually low levels of intraspecific variation during postnatal development. It is now clear that birds inherited their high rates of growth from their dinosaurian ancestors, but the origin of the avian condition of low variation during development is poorly constrained. The most well-understood growth trajectories of later Mesozoic theropods (e.g., Tyrannosaurus, Allosaurus) show similarly low variation to birds, contrasting with higher variation in extant crocodylians. Here, we show that deep within Dinosauria, among the earliest-diverging dinosaurs, anomalously high intraspecific variation is widespread but then is lost in more derived theropods. This style of development is ancestral for dinosaurs and their closest relatives, and, surprisingly, this level of variation is far higher than in living crocodylians. Among early dinosaurs, this variation is widespread across Pangaea in the Triassic and Early Jurassic, and among early-diverging theropods (ceratosaurs), this variation is maintained for 165 million years to the end of the Cretaceous. Because the Late Triassic environment across Pangaea was volatile and heterogeneous, this variation may have contributed to the rise of dinosaurian dominance through the end of the Triassic Period.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC5187714/",
    doi = "10.1073/pnas.1613813113",
    openalex = "W2560017686",
    pmcid = "PMC5187714",
    pmid = "27930315",
    references = "carr1999craniofacial, doi101002sici109746871996082292121aidjmor130co24, doi101007s1205200901334, doi101016jcub201408034, doi101016jearscirev201004001, doi101016s0012825203000825, doi10103835086500, doi10103835086558, doi101038nature02699, doi101073pnas1505252112, doi10108002724634199610011283, doi101111bij12746, doi105860choice392183"
}

Identification of the ontogenetic status of an extinct organism is complex, and yet this underpins major areas of research, from taxonomy and systematics to ecology and evolution. In the case of the non-avialan dinosaurs, at least some were reproductively mature before they were skeletally mature, and a lack of consensus on how to define an 'adult' animal causes problems for even basic scientific investigations. Here we review the current methods available to determine the age of non-avialan dinosaurs, discuss the definitions of different ontogenetic stages, and summarize the implications of these disparate definitions for dinosaur palaeontology. Most critically, a growing body of evidence suggests that many dinosaurs that would be considered 'adults' in a modern-day field study are considered 'juveniles' or 'subadults' in palaeontological contexts.

@article{doi101098rsbl20150947,
    author = "Hone, David W. E. and Farke, Andrew A. and Wedel, Matt",
    title = "Ontogeny and the fossil record: what, if anything, is an adult dinosaur?",
    year = "2016",
    journal = "Biology Letters",
    abstract = "Identification of the ontogenetic status of an extinct organism is complex, and yet this underpins major areas of research, from taxonomy and systematics to ecology and evolution. In the case of the non-avialan dinosaurs, at least some were reproductively mature before they were skeletally mature, and a lack of consensus on how to define an 'adult' animal causes problems for even basic scientific investigations. Here we review the current methods available to determine the age of non-avialan dinosaurs, discuss the definitions of different ontogenetic stages, and summarize the implications of these disparate definitions for dinosaur palaeontology. Most critically, a growing body of evidence suggests that many dinosaurs that would be considered 'adults' in a modern-day field study are considered 'juveniles' or 'subadults' in palaeontological contexts.",
    url = "https://doi.org/10.1098/rsbl.2015.0947",
    doi = "10.1098/rsbl.2015.0947",
    openalex = "W2279103404",
    references = "carr1999craniofacial, doi101007s0001501000242, doi101017pab201519, doi10103835086558, doi101038nature04633, doi101073pnas0708903105, doi101073pnas1313334111, doi10108002724634199610011283, doi10108002724634199910011161, doi101080027246342010483632, doi101093sysbio24137, doi101098rsbl20070254, doi101111j109636421997tb00340x, doi101111j15023931201100300x, doi101146annurevearth060313054858, doi101371journalpone0021376, doi1016660094837320010270039coosea20co2, doi1016660094837320040300253chopom20co2, doi1016660094837320080340247ositlb20co2, doi1016690883135120010160482ttoaco20co2, doi1016710272463420000200115lbhoth20co2, doi10167102724634200727350asoitp20co2, doi1016710390290119, doi1023071564148, erickson2014on, martinsander2006bone"
}

Abstract The demonstration of sexual dimorphism in the fossil record can provide vital information about the role that sexual selection has played in the evolution of life. However, statistically robust inferences of sexual dimorphism in fossil organisms are exceedingly difficult to establish, owing to issues of sample size, experimental control, and methodology. This is particularly so in the case of dinosaurs, for which sexual dimorphism has been posited in many species, yet quantifiable data are often lacking. This study presents the first statistical investigation of sexual dimorphism across Dinosauria. It revisits prior analyses that purport to find quantitative evidence for sexual dimorphism in nine dinosaur species. After the available morphological data were subjected to a suite of statistical tests (normality and unimodality tests and mixture modeling), no evidence for sexual dimorphism was found in any of the examined taxa, contrary to conventional wisdom. This is not to say that dinosaurs were not sexually dimorphic (phylogenetic inference suggests they may well have been), only that the available evidence precludes its detection. A priori knowledge of the sexes would greatly facilitate the assessment of sexual dimorphism in the fossil record, and it is suggested that unambiguous indicators of sex (e.g., presence of eggs, embryos, medullary bone) be used to this end.

@article{doi101017pab201651,
    author = "Mallon, Jordan C.",
    title = "Recognizing sexual dimorphism in the fossil record: lessons from nonavian dinosaurs",
    year = "2017",
    journal = "Paleobiology",
    abstract = "Abstract The demonstration of sexual dimorphism in the fossil record can provide vital information about the role that sexual selection has played in the evolution of life. However, statistically robust inferences of sexual dimorphism in fossil organisms are exceedingly difficult to establish, owing to issues of sample size, experimental control, and methodology. This is particularly so in the case of dinosaurs, for which sexual dimorphism has been posited in many species, yet quantifiable data are often lacking. This study presents the first statistical investigation of sexual dimorphism across Dinosauria. It revisits prior analyses that purport to find quantitative evidence for sexual dimorphism in nine dinosaur species. After the available morphological data were subjected to a suite of statistical tests (normality and unimodality tests and mixture modeling), no evidence for sexual dimorphism was found in any of the examined taxa, contrary to conventional wisdom. This is not to say that dinosaurs were not sexually dimorphic (phylogenetic inference suggests they may well have been), only that the available evidence precludes its detection. A priori knowledge of the sexes would greatly facilitate the assessment of sexual dimorphism in the fossil record, and it is suggested that unambiguous indicators of sex (e.g., presence of eggs, embryos, medullary bone) be used to this end.",
    url = "https://doi.org/10.1017/pab.2016.51",
    doi = "10.1017/pab.2016.51",
    openalex = "W2598969013",
    references = "doi101002ar20991, doi101017pab201519, doi10108002724634198510011859, doi10108008912960903450505, doi101098rsbl20150947, doi101111j15023931201100300x, doi101371journalpone0029958, openalexw3215035079"
}

The relationship between dinosaurs and other reptiles is well established, but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies. The closest extinct relatives of dinosaurs either have highly derived morphologies or are known from poorly preserved or incomplete material. Here we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch. The anatomy of T. rhadinus provides key information that unites several enigmatic taxa from across Pangaea into a previously unrecognized clade, Aphanosauria. This clade is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia. We demonstrate that several anatomical features long thought to characterize Dinosauria and dinosauriforms evolved much earlier, soon after the bird-crocodylian split, and that the earliest avemetatarsalians retained the crocodylian-like ankle morphology and hindlimb proportions of stem archosaurs and early pseudosuchians. Early avemetatarsalians were substantially more species-rich, widely geographically distributed and morphologically diverse than previously recognized. Moreover, several early dinosauromorphs that were previously used as models to understand dinosaur origins may represent specialized forms rather than the ancestral avemetatarsalian morphology.

@article{doi101038nature22037,
    author = "Nesbitt, Sterling J. and Butler, Richard J. and Ezcurra, Martín D. and Barrett, Paul M. and Stocker, Michelle R. and Angielczyk, Kenneth D. and Smith, Roger M. H. and Sidor, Christian A. and Niedźwiedzki, Grzegorz and Сенников, А. Г. and Charig, Alan J.",
    title = "The earliest bird-line archosaurs and the assembly of the dinosaur body plan",
    year = "2017",
    journal = "Nature",
    abstract = "The relationship between dinosaurs and other reptiles is well established, but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies. The closest extinct relatives of dinosaurs either have highly derived morphologies or are known from poorly preserved or incomplete material. Here we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch. The anatomy of T. rhadinus provides key information that unites several enigmatic taxa from across Pangaea into a previously unrecognized clade, Aphanosauria. This clade is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia. We demonstrate that several anatomical features long thought to characterize Dinosauria and dinosauriforms evolved much earlier, soon after the bird-crocodylian split, and that the earliest avemetatarsalians retained the crocodylian-like ankle morphology and hindlimb proportions of stem archosaurs and early pseudosuchians. Early avemetatarsalians were substantially more species-rich, widely geographically distributed and morphologically diverse than previously recognized. Moreover, several early dinosauromorphs that were previously used as models to understand dinosaur origins may represent specialized forms rather than the ancestral avemetatarsalian morphology.",
    url = "https://doi.org/10.1038/nature22037",
    doi = "10.1038/nature22037",
    openalex = "W2606337068",
    references = "doi1010160169534789901626, doi10108002724634199110011426, doi101080027246342013820113, doi101111bij12746, doi101111cla12160, doi101111j10960031200800217x, doi101111j136530911989tb00817x, doi101111j1469185x200900094x, doi101126science1161833, doi101126science28454232137, doi1012060003009020073021taoeoa20co2, doi1012063521, doi1016710272463420040240555gisdap20co2, doi1023071005355, doi105281zenodo16171435, doi107717peerj1778, nesbitt2013the"
}

Dinosauromorphs evolved a wide diversity of hind limb skeletal morphologies, suggesting highly divergent articular soft tissue anatomies. However, poor preservation of articular soft tissues in fossils has hampered any follow-on functional inferences. We reconstruct the hip joint soft tissue anatomy of non-dinosaurian dinosauromorphs and early dinosaurs using osteological correlates derived from extant sauropsids and infer trends in character transitions along the theropod and sauropodomorph lineagues. Femora and pelves of 107 dinosauromorphs and outgroup taxa were digitized using 3D imaging techniques. Key transitions were estimated using maximum likelihood ancestral state reconstruction. The hips of dinosauromorphs possessed wide a disparity of soft tissue morphologies beyond the types and combinations exhibited by extant archosaurs. Early evolution of the dinosauriform hip joint was characterized by the retention of a prominent femoral hyaline cartilage cone in post-neonatal individuals, with the cartilage cone independently reduced within theropods and sauropodomorphs. The femur of Dinosauriformes possessed a fibrocartilage sleeve on the metaphysis, which surrounded a hyaline core. The acetabulum of Dinosauriformes possessed distinct labrum and antitrochanter structures. In sauropodomorphs, hip congruence was maintained by thick hyaline cartilage on the femoral head, whereas theropods relied on acetabular tissues such as ligaments and articular pads. In particular, the craniolaterally ossified hip capsule of non-Avetheropoda neotheropods permitted mostly parasagittal femoral movements. These data indicate that the dinosauromorph hip underwent mosaic evolution within the saurischian lineage and that sauropodomorphs and theropods underwent both convergence and divergence in articular soft tissues, correlated with transitions in body size, locomotor posture, and joint loading.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Tsai, H. P., K. M. Middleton, J. R. Hutchinson, and C. M. Holliday. 2018. Hip joint articular soft tissues of non-dinosaurian Dinosauromorpha and early Dinosauria: evolutionary and biomechanical implications for Saurischia. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1427593.

@article{doi1010800272463420171427593,
    author = "Tsai, Henry P. and Middleton, Kevin M. and Hutchinson, John R. and Holliday, Casey M.",
    title = "Hip joint articular soft tissues of non-dinosaurian Dinosauromorpha and early Dinosauria: evolutionary and biomechanical implications for Saurischia",
    year = "2018",
    journal = "Journal of Vertebrate Paleontology",
    abstract = "Dinosauromorphs evolved a wide diversity of hind limb skeletal morphologies, suggesting highly divergent articular soft tissue anatomies. However, poor preservation of articular soft tissues in fossils has hampered any follow-on functional inferences. We reconstruct the hip joint soft tissue anatomy of non-dinosaurian dinosauromorphs and early dinosaurs using osteological correlates derived from extant sauropsids and infer trends in character transitions along the theropod and sauropodomorph lineagues. Femora and pelves of 107 dinosauromorphs and outgroup taxa were digitized using 3D imaging techniques. Key transitions were estimated using maximum likelihood ancestral state reconstruction. The hips of dinosauromorphs possessed wide a disparity of soft tissue morphologies beyond the types and combinations exhibited by extant archosaurs. Early evolution of the dinosauriform hip joint was characterized by the retention of a prominent femoral hyaline cartilage cone in post-neonatal individuals, with the cartilage cone independently reduced within theropods and sauropodomorphs. The femur of Dinosauriformes possessed a fibrocartilage sleeve on the metaphysis, which surrounded a hyaline core. The acetabulum of Dinosauriformes possessed distinct labrum and antitrochanter structures. In sauropodomorphs, hip congruence was maintained by thick hyaline cartilage on the femoral head, whereas theropods relied on acetabular tissues such as ligaments and articular pads. In particular, the craniolaterally ossified hip capsule of non-Avetheropoda neotheropods permitted mostly parasagittal femoral movements. These data indicate that the dinosauromorph hip underwent mosaic evolution within the saurischian lineage and that sauropodomorphs and theropods underwent both convergence and divergence in articular soft tissues, correlated with transitions in body size, locomotor posture, and joint loading.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Tsai, H. P., K. M. Middleton, J. R. Hutchinson, and C. M. Holliday. 2018. Hip joint articular soft tissues of non-dinosaurian Dinosauromorpha and early Dinosauria: evolutionary and biomechanical implications for Saurischia. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1427593.",
    url = "https://doi.org/10.1080/02724634.2017.1427593",
    doi = "10.1080/02724634.2017.1427593",
    openalex = "W2791846447",
    references = "doi101007s0001501000242, doi101046j10963642200200029x, doi101073pnas1613813113, doi101080106351501753462876, doi101080106351599260184, doi101098rsbl20060523, doi101098rsbl20150947, doi101111j155856461997tb05095x, doi101126science10246376, doi101126science2562999, doi101126science26251422020, doi101144sp3799, doi1012063521, doi101371journalpone0013120, doi101590s000137652011000100005, doi101666100041, doi10230730135049, doi104202app20090075, doi105860choice326223"
}

Poropat, S.F., Martin, S.K., Tosolini, A.-M.P., Wagstaff, B.E, Bean, L.B., Kear, B.P., Vickers-Rich, P. & Rich, T.H., May 2018. Early Cretaceous polar biotas of Victoria, southeastern Australia—an overview of research to date. Alcheringa 42, 158–230. ISSN 0311-5518. Although Cretaceous fossils (coal excluded) from Victoria, Australia, were first reported in the 1850s, it was not until the 1950s that detailed studies of these fossils were undertaken. Numerous fossil localities have been identified in Victoria since the 1960s, including the Koonwarra Fossil Bed (Strzelecki Group) near Leongatha, the Dinosaur Cove and Eric the Red West sites (Otway Group) at Cape Otway, and the Flat Rocks site (Strzelecki Group) near Cape Paterson. Systematic exploration over the past five decades has resulted in the collection of thousands of fossils representing various plants, invertebrates and vertebrates. Some of the best-preserved and most diverse Hauterivian–Barremian floral assemblages in Australia derive from outcrops of the lower Strzelecki Group in the Gippsland Basin. The slightly younger Koonwarra Fossil Bed (Aptian) is a Konservat-Lagerstätte that also preserves abundant plants, including one of the oldest known flowers. In addition, insects, crustaceans (including the only syncaridans known from Australia between the Triassic and the present), arachnids (including Australia’s only known opilione), the stratigraphically youngest xiphosurans from Australia, bryozoans, unionoid molluscs and a rich assemblage of actinopterygian fish are known from the Koonwarra Fossil Bed. The oldest known—and only Mesozoic—fossil feathers from the Australian continent constitute the only evidence for tetrapods at Koonwarra. By contrast, the Barremian–Aptian-aged deposits at the Flat Rocks site, and the Aptian–Albian-aged strata at the Dinosaur Cove and Eric the Red West sites, are all dominated by tetrapod fossils, with actinopterygians and dipnoans relatively rare. Small ornithopod (=basal neornithischian) dinosaurs are numerically common, known from four partial skeletons and a multitude of isolated bones. Aquatic meiolaniform turtles constitute another prominent faunal element, represented by numerous isolated bones and articulated carapaces and plastrons. More than 50 specimens—mostly lower jaws—evince a high diversity of mammals, including monotremes, a multituberculate and several enigmatic ausktribosphenids. Relatively minor components of these fossil assemblages are diverse theropods (including birds), rare ankylosaurs and ceratopsians, pterosaurs, non-marine plesiosaurs and a lepidosaur. In the older strata of the upper Strzelecki Group, temnospondyl amphibians—the youngest known worldwide—are a conspicuous component of the fauna, whereas crocodylomorphs appear to be present only in up-sequence deposits of the Otway Group. Invertebrates are uncommon, although decapod crustaceans and unionoid bivalves have been described. Collectively, the Early Cretaceous biota of Victoria provides insights into a unique Mesozoic high-latitude palaeoenvironment and elucidates both palaeoclimatic and palaeobiogeographic changes throughout more than 25 million years of geological time. Stephen F. Poropat*† [sporopat@swin.edu.au; stephenfporopat@gmail.com], Faculty of Science, Engineering and Technology, Swinburne University of Technology, John St, Hawthorn, Victoria 3122, Australia; Sarah K. Martin*‡ [sarah.martin@dmirs.wa.gov.au; martin.sarahk@gmail.com] Geological Survey of Western Australia, 100 Plain St, East Perth, Western Australia 6004, Australia; Anne-Marie P. Tosolini [a.tosolini@unimelb.edu.au] and Barbara E. Wagstaff [wagstaff@unimelb.edu.au] School of Earth Sciences, The University of Melbourne, Melbourne, Victoria 3010, Australia; Lynne B. Bean [lynne.bean@anu.edu.au] Research School of Earth Sciences, Australian National University, Acton, Canberra, Australian Capital Territory 2001, Australia; Benjamin P. Kear [benjamin.kear@em.uu.se] Museum of Evolution, Uppsala University, Norbyvägen 16, Uppsala SE-752 36, Sweden; Patricia Vickers-Rich§ [prich@swin.edu.au; pat.rich@monash.edu] Faculty of Science, Engineering and Technology, Swinburne University of Technology, John St, Hawthorn, Victoria 3122, Australia; Thomas H. Rich [trich@museum.vic.gov.au] Museum Victoria, PO Box 666, Melbourne, Victoria 3001, Australia. *These authors contributed equally to this work. †Also affiliated with: Australian Age of Dinosaurs Museum of Natural History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia. ‡Also affiliated with: Earth and Planetary Sciences, Western Australian Museum, Welshpool, Western Australia 6101, Australia. §Also affiliated with: School of Earth, Atmosphere and Environment, Monash University, Melbourne, Victoria 3800, Australia.

@article{doi1010800311551820181453085,
    author = "Poropat, Stephen F. and Martin, Sarah K. and Tosolini, Anne-Marie P. and Wagstaff, Barbara E. and Bean, Lynne B. and Kear, Benjamin P. and Vickers-Rich, Patricia and Rich, Thomas H.",
    title = "Early Cretaceous polar biotas of Victoria, southeastern Australia—an overview of research to date",
    year = "2018",
    journal = "Alcheringa An Australasian Journal of Palaeontology",
    abstract = "Poropat, S.F., Martin, S.K., Tosolini, A.-M.P., Wagstaff, B.E, Bean, L.B., Kear, B.P., Vickers-Rich, P. \& Rich, T.H., May 2018. Early Cretaceous polar biotas of Victoria, southeastern Australia—an overview of research to date. Alcheringa 42, 158–230. ISSN 0311-5518. Although Cretaceous fossils (coal excluded) from Victoria, Australia, were first reported in the 1850s, it was not until the 1950s that detailed studies of these fossils were undertaken. Numerous fossil localities have been identified in Victoria since the 1960s, including the Koonwarra Fossil Bed (Strzelecki Group) near Leongatha, the Dinosaur Cove and Eric the Red West sites (Otway Group) at Cape Otway, and the Flat Rocks site (Strzelecki Group) near Cape Paterson. Systematic exploration over the past five decades has resulted in the collection of thousands of fossils representing various plants, invertebrates and vertebrates. Some of the best-preserved and most diverse Hauterivian–Barremian floral assemblages in Australia derive from outcrops of the lower Strzelecki Group in the Gippsland Basin. The slightly younger Koonwarra Fossil Bed (Aptian) is a Konservat-Lagerstätte that also preserves abundant plants, including one of the oldest known flowers. In addition, insects, crustaceans (including the only syncaridans known from Australia between the Triassic and the present), arachnids (including Australia’s only known opilione), the stratigraphically youngest xiphosurans from Australia, bryozoans, unionoid molluscs and a rich assemblage of actinopterygian fish are known from the Koonwarra Fossil Bed. The oldest known—and only Mesozoic—fossil feathers from the Australian continent constitute the only evidence for tetrapods at Koonwarra. By contrast, the Barremian–Aptian-aged deposits at the Flat Rocks site, and the Aptian–Albian-aged strata at the Dinosaur Cove and Eric the Red West sites, are all dominated by tetrapod fossils, with actinopterygians and dipnoans relatively rare. Small ornithopod (=basal neornithischian) dinosaurs are numerically common, known from four partial skeletons and a multitude of isolated bones. Aquatic meiolaniform turtles constitute another prominent faunal element, represented by numerous isolated bones and articulated carapaces and plastrons. More than 50 specimens—mostly lower jaws—evince a high diversity of mammals, including monotremes, a multituberculate and several enigmatic ausktribosphenids. Relatively minor components of these fossil assemblages are diverse theropods (including birds), rare ankylosaurs and ceratopsians, pterosaurs, non-marine plesiosaurs and a lepidosaur. In the older strata of the upper Strzelecki Group, temnospondyl amphibians—the youngest known worldwide—are a conspicuous component of the fauna, whereas crocodylomorphs appear to be present only in up-sequence deposits of the Otway Group. Invertebrates are uncommon, although decapod crustaceans and unionoid bivalves have been described. Collectively, the Early Cretaceous biota of Victoria provides insights into a unique Mesozoic high-latitude palaeoenvironment and elucidates both palaeoclimatic and palaeobiogeographic changes throughout more than 25 million years of geological time. Stephen F. Poropat*† [sporopat@swin.edu.au; stephenfporopat@gmail.com], Faculty of Science, Engineering and Technology, Swinburne University of Technology, John St, Hawthorn, Victoria 3122, Australia; Sarah K. Martin*‡ [sarah.martin@dmirs.wa.gov.au; martin.sarahk@gmail.com] Geological Survey of Western Australia, 100 Plain St, East Perth, Western Australia 6004, Australia; Anne-Marie P. Tosolini [a.tosolini@unimelb.edu.au] and Barbara E. Wagstaff [wagstaff@unimelb.edu.au] School of Earth Sciences, The University of Melbourne, Melbourne, Victoria 3010, Australia; Lynne B. Bean [lynne.bean@anu.edu.au] Research School of Earth Sciences, Australian National University, Acton, Canberra, Australian Capital Territory 2001, Australia; Benjamin P. Kear [benjamin.kear@em.uu.se] Museum of Evolution, Uppsala University, Norbyvägen 16, Uppsala SE-752 36, Sweden; Patricia Vickers-Rich§ [prich@swin.edu.au; pat.rich@monash.edu] Faculty of Science, Engineering and Technology, Swinburne University of Technology, John St, Hawthorn, Victoria 3122, Australia; Thomas H. Rich [trich@museum.vic.gov.au] Museum Victoria, PO Box 666, Melbourne, Victoria 3001, Australia. *These authors contributed equally to this work. †Also affiliated with: Australian Age of Dinosaurs Museum of Natural History, Lot 1 Dinosaur Drive, PO Box 408, Winton, Queensland 4735, Australia. ‡Also affiliated with: Earth and Planetary Sciences, Western Australian Museum, Welshpool, Western Australia 6101, Australia. §Also affiliated with: School of Earth, Atmosphere and Environment, Monash University, Melbourne, Victoria 3800, Australia.",
    url = "https://doi.org/10.1080/03115518.2018.1453085",
    doi = "10.1080/03115518.2018.1453085",
    openalex = "W2802532600",
    references = "doi1010070306475774, doi101016jearscirev201203002, doi101016jearscirev201206007, doi101016jgr201403014, doi101016jjafrearsci201205005, doi101016jpalaeo201508011, doi10103834356, doi101038srep34467, doi101071bt00023, doi101071zo9550654, doi10108011035890902924877, doi1010801477201920151059985, doi1010801477201920171371258, doi101098rspb20060443, doi101371journalpone0126946, doi1033740140580105, doi105860choice296275, doi105860choice404600, doi105860choice503272, doi107312kiel11918, doi107717peerj1523, openalexw1900040508, sereno2017early"
}

Abstract The collection and dissemination of vertebrate ichnological data is struggling to keep up with techniques that are becoming commonplace in the wider palaeontological field. A standard protocol is required to ensure that data is recorded, presented and archived in a manner that will be useful both to contemporary researchers, and to future generations. Primarily, our aim is to make the 3D capture of ichnological data standard practice, and to provide guidance on how such 3D data can be communicated effectively (both via the literature and other means) and archived openly and in perpetuity. We recommend capture of 3D data, and the presentation of said data in the form of photographs, false‐colour images, and interpretive drawings. Raw data (3D models of traces) should always be provided in a form usable by other researchers (i.e. in an open format). If adopted by the field as a whole, the result will be a more robust and uniform literature, supplemented by unparalleled availability of datasets for future workers.

@article{doi101111pala12373,
    author = "Falkingham, Peter and Bates, Karl T. and Avanzini, Marco and Bennett, Matthew R. and Bordy, Emese M. and Breithaupt, Brent H. and Castanera, Diego and Citton, Paolo and Díaz‐Martínez, Ignacio and Farlow, Jim O. and Fiorillo, Anthony R. and Gatesy, Stephen M. and Getty, Patrick R. and Hatala, Kevin G. and Hornung, Jahn J. and Hyatt, James A. and Klein, Hendrik and Lallensack, Jens N. and Martin, Anthony J. and Marty, Daniel and Matthews, Neffra A. and Meyer, Christian A. and Milàn, Jesper and Minter, Nicholas J. and Razzolini, Novella L. and Romilio, Anthony and Salisbury, Steven W. and Sciscio, Lara and Tanaka, Ikuko and Wiseman, Ashleigh L. A. and Xing, Lida and Belvedere, Matteo",
    title = "A standard protocol for documenting modern and fossil ichnological data",
    year = "2018",
    journal = "Palaeontology",
    abstract = "Abstract The collection and dissemination of vertebrate ichnological data is struggling to keep up with techniques that are becoming commonplace in the wider palaeontological field. A standard protocol is required to ensure that data is recorded, presented and archived in a manner that will be useful both to contemporary researchers, and to future generations. Primarily, our aim is to make the 3D capture of ichnological data standard practice, and to provide guidance on how such 3D data can be communicated effectively (both via the literature and other means) and archived openly and in perpetuity. We recommend capture of 3D data, and the presentation of said data in the form of photographs, false‐colour images, and interpretive drawings. Raw data (3D models of traces) should always be provided in a form usable by other researchers (i.e. in an open format). If adopted by the field as a whole, the result will be a more robust and uniform literature, supplemented by unparalleled availability of datasets for future workers.",
    url = "https://doi.org/10.1111/pala.12373",
    doi = "10.1111/pala.12373",
    openalex = "W2802346987",
    references = "doi1010079789400904095, doi101016jpalaeo200412022, doi101016s001669958880038x, doi10103820167, doi101073pnas1416252111, doi1010800272463420161269539, doi1010800272463420171314298, doi10108010420940802471027, doi101098rspb20170194, doi101111jzo12110, doi101144gslsp20042280106, doi101371journalpone0103613, doi101371journalpone0180289, doi1023071445147, doi1023073514816, doi1026879264, doi1026879529, doi107717peerj2059, openalexw2593733766, openalexw2619609965"
}

@article{doi101016jearscirev201904008,
    author = "Marchetti, Lorenzo and Belvedere, Matteo and Voigt, Sebastian and Klein, Hendrik and Castanera, Diego and Díaz‐Martínez, Ignacio and Marty, Daniel and Xing, Lida and Feola, Silverio and Melchor, Ricardo N. and Farlow, James O.",
    title = "Defining the morphological quality of fossil footprints. Problems and principles of preservation in tetrapod ichnology with examples from the Palaeozoic to the present",
    year = "2019",
    journal = "Earth-Science Reviews",
    url = "https://doi.org/10.1016/j.earscirev.2019.04.008",
    doi = "10.1016/j.earscirev.2019.04.008",
    openalex = "W2937229098",
    references = "doi1010079783540472261, doi1010160025322767900515, doi101016jearscirev201608009, doi101016s0012821x0100588x, doi101016s0031018296001423, doi101016s0031018297852005, doi101017cbo9780511975622, doi101017s0025315400028198, doi101017s0025315400028575, doi101017s009483730001143x, doi101017s0094837300026907, doi10103820167, doi101073pnas1416252111, doi10108000241160600787890, doi10108002724634199510011271, doi1010800272463420171314298, doi10108008912960903503345, doi1010801042094020171350856, doi10108010420940802471027, doi101098rstb19920051, doi101111jzo12110, doi101144pygs543185, doi101371journalpone0004591, doi101371journalpone0180289, doi10166600948373200026103tap20co2, doi1023073514457, doi1023073514964, doi105860choice273305, doi105860choice435907, doi105860choice456807, doi107312lock90868, openalexw2149387945, openalexw2619609965, openalexw39955589, openalexw560158229"
}

Tooth replacement rate is an important contributor to feeding ecology for polyphyodont animals. Dinosaurs exhibit a wide range of tooth replacement rates, mirroring their diverse craniofacial specializations, but little is known about broad-scale allometric or evolutionary patterns within the group. In the current broad but sparse dinosaurian sample, only three non-avian theropod tooth replacement rates have been estimated. We estimated tooth formation and replacement rates in three additional non-avian theropod dinosaurs, the derived latest Cretaceous abelisaurid Majungasaurus and the more generalized Late Jurassic Allosaurus and Ceratosaurus. We created the largest dental histological and CT dataset for any theropod dinosaur, sectioning and scanning over a dozen toothed elements of Majungasaurus and several additional elements from the other two genera. Using this large sample, we created models of tooth formation time that allow for theropod replacement rates to be estimated non-destructively. In contrast to previous results for theropods, we found high tooth replacement rates in all three genera, with Allosaurus and Ceratosaurus rates of \textasciitilde 100 days and 56 days for Majungasaurus. The latter rate is on par with those of derived herbivorous dinosaurs including some neosauropods, hadrosaurids, and ceratopsians. This elevated rate may be a response to high rates of tooth wear in Majungasaurus. Within Dinosauria, there is no relationship between body mass and tooth replacement rate and no trends in replacement rate over time. Rather, tooth replacement rate is clade-specific, with elevated rates in abelisaurids and diplodocoids and lower rates in coelurosaurs.

@article{doi101371journalpone0224734,
    author = "D'Emic, Michael D and O'Connor, Patrick M and Pascucci, Thomas R and Gavras, Joanna N and Mardakhayava, Elizabeth and Lund, Eric K",
    title = "Evolution of high tooth replacement rates in theropod dinosaurs.",
    year = "2019",
    journal = "PloS one",
    abstract = "Tooth replacement rate is an important contributor to feeding ecology for polyphyodont animals. Dinosaurs exhibit a wide range of tooth replacement rates, mirroring their diverse craniofacial specializations, but little is known about broad-scale allometric or evolutionary patterns within the group. In the current broad but sparse dinosaurian sample, only three non-avian theropod tooth replacement rates have been estimated. We estimated tooth formation and replacement rates in three additional non-avian theropod dinosaurs, the derived latest Cretaceous abelisaurid Majungasaurus and the more generalized Late Jurassic Allosaurus and Ceratosaurus. We created the largest dental histological and CT dataset for any theropod dinosaur, sectioning and scanning over a dozen toothed elements of Majungasaurus and several additional elements from the other two genera. Using this large sample, we created models of tooth formation time that allow for theropod replacement rates to be estimated non-destructively. In contrast to previous results for theropods, we found high tooth replacement rates in all three genera, with Allosaurus and Ceratosaurus rates of \textasciitilde 100 days and 56 days for Majungasaurus. The latter rate is on par with those of derived herbivorous dinosaurs including some neosauropods, hadrosaurids, and ceratopsians. This elevated rate may be a response to high rates of tooth wear in Majungasaurus. Within Dinosauria, there is no relationship between body mass and tooth replacement rate and no trends in replacement rate over time. Rather, tooth replacement rate is clade-specific, with elevated rates in abelisaurids and diplodocoids and lower rates in coelurosaurs.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC6880968/",
    doi = "10.1371/journal.pone.0224734",
    openalex = "W2997465389",
    pmcid = "PMC6880968",
    pmid = "31774829",
    references = "doi101007s0011401006506, doi101073pnas932514623, doi1011112041210x12226, doi101186174170071060, doi101371journalpbio1001853, doi101371journalpone0001230, doi1016710272463420072732caomct20co2, doi104202app20080102, doi105962bhltitle52196, openalexw2183707334"
}

@article{doi101016janbehav202009010,
    author = "Hsieh, Shannon and Plotnick, Roy E.",
    title = "The representation of animal behaviour in the fossil record",
    year = "2020",
    journal = "Animal Behaviour",
    url = "https://doi.org/10.1016/j.anbehav.2020.09.010",
    doi = "10.1016/j.anbehav.2020.09.010",
    openalex = "W3091839592",
    references = "doi10100703064746897, doi101016jtree201901004, doi101016s004724847880102x, doi101017s0094837300003778, doi101038srep18952, doi101073pnas0800375105, doi101093aesa383396, doi101111j143903101963tb01161x, doi101186s1286201812626, doi1023071438156, openalexw1503181416, openalexw1983092075"
}

@article{doi101016jearscirev2020103320,
    author = "Falkingham, Peter and Gatesy, Stephen M.",
    title = "Discussion: Defining the morphological quality of fossil footprints. Problems and principles of preservation in tetrapod ichnology with examples from the Palaeozoic to the present by Lorenzo Marchetti et al.",
    year = "2020",
    journal = "Earth-Science Reviews",
    url = "https://doi.org/10.1016/j.earscirev.2020.103320",
    doi = "10.1016/j.earscirev.2020.103320",
    openalex = "W3047844386",
    references = "doi1010800272463420171314298"
}

@article{doi101016jjsames2020102936,
    author = "de Souza Carvalho, Ismar and Leonardi, Giuseppe",
    title = "Fossil footprints as biosedimentary structures for paleoenvironmental interpretation: Examples from Gondwana",
    year = "2020",
    journal = "Journal of South American Earth Sciences",
    url = "https://doi.org/10.1016/j.jsames.2020.102936",
    doi = "10.1016/j.jsames.2020.102936",
    openalex = "W3092431150",
    references = "doi101016jcretres2020104626, doi101016jjsames201206017, doi102110jsr201957, doi107717peerj5358"
}

Abstract Despite reports of sexual dimorphism in extinct taxa, such claims in non-avian dinosaurs have been rare over the last decade and have often been criticized. Since dimorphism is widespread in sexually reproducing organisms today, under-reporting in the literature might suggest either methodological shortcomings or that this diverse group exhibited highly unusual reproductive biology. Univariate significance testing, especially for bimodality, is ineffective and prone to false negatives. Species recognition and mutual sexual selection hypotheses, therefore, may not be required to explain supposed absence of sexual dimorphism across the grade (a type II error). Instead, multiple lines of evidence support sexual selection and variation of structures consistent with secondary sexual characteristics, strongly suggesting sexual dimorphism in non-avian dinosaurs. We propose a framework for studying sexual dimorphism in fossils, focusing on likely secondary sexual traits and testing against all alternate hypotheses for variation in them using multiple lines of evidence. We use effect size statistics appropriate for low sample sizes, rather than significance testing, to analyse potential divergence of growth curves in traits and constrain estimates for dimorphism magnitude. In many cases, estimates of sexual variation can be reasonably accurate, and further developments in methods to improve sex assignments and account for intrasexual variation (e.g. mixture modelling) will improve accuracy. It is better to compare estimates for the magnitude of and support for dimorphism between datasets than to dichotomously reject or fail to reject monomorphism in a single species, enabling the study of sexual selection across phylogenies and time. We defend our approach with simulated and empirical data, including dinosaur data, showing that even simple approaches can yield fairly accurate estimates of sexual variation in many cases, allowing for comparison of species with high and low support for sexual variation.

@article{doi101093biolinneanblaa105,
    author = "Saitta, Evan T. and Stockdale, Maximilian T. and Longrich, Nicholas R. and Bonhomme, Vincent and Benton, Michael J. and Cuthill, Innes C. and Makovicky, Peter J.",
    title = "An effect size statistical framework for investigating sexual dimorphism in non-avian dinosaurs and other extinct taxa",
    year = "2020",
    journal = "Biological Journal of the Linnean Society",
    abstract = "Abstract Despite reports of sexual dimorphism in extinct taxa, such claims in non-avian dinosaurs have been rare over the last decade and have often been criticized. Since dimorphism is widespread in sexually reproducing organisms today, under-reporting in the literature might suggest either methodological shortcomings or that this diverse group exhibited highly unusual reproductive biology. Univariate significance testing, especially for bimodality, is ineffective and prone to false negatives. Species recognition and mutual sexual selection hypotheses, therefore, may not be required to explain supposed absence of sexual dimorphism across the grade (a type II error). Instead, multiple lines of evidence support sexual selection and variation of structures consistent with secondary sexual characteristics, strongly suggesting sexual dimorphism in non-avian dinosaurs. We propose a framework for studying sexual dimorphism in fossils, focusing on likely secondary sexual traits and testing against all alternate hypotheses for variation in them using multiple lines of evidence. We use effect size statistics appropriate for low sample sizes, rather than significance testing, to analyse potential divergence of growth curves in traits and constrain estimates for dimorphism magnitude. In many cases, estimates of sexual variation can be reasonably accurate, and further developments in methods to improve sex assignments and account for intrasexual variation (e.g. mixture modelling) will improve accuracy. It is better to compare estimates for the magnitude of and support for dimorphism between datasets than to dichotomously reject or fail to reject monomorphism in a single species, enabling the study of sexual selection across phylogenies and time. We defend our approach with simulated and empirical data, including dinosaur data, showing that even simple approaches can yield fairly accurate estimates of sexual variation in many cases, allowing for comparison of species with high and low support for sexual variation.",
    url = "https://doi.org/10.1093/biolinnean/blaa105",
    doi = "10.1093/biolinnean/blaa105",
    openalex = "W3082435594",
    references = "doi101007s1065401601493, doi101016jcub201706071, doi101038246015a0, doi101038s4146701702088w, doi101038srep18952, doi101073pnas1313334111, doi1010800003130520161154108, doi10108008912960903450505, doi101111brv12436, doi101111j1469185x1970tb01176x, doi101111j1469185x200700027x, doi101126science13134091292, doi1015159780691207278, doi101537ase188722495, doi1016710390290119, doi1023072874"
}

The independent evolution of gigantism among dinosaurs has been a topic of long-standing interest, but it remains unclear if gigantic theropods, the largest bipeds in the fossil record, all achieved massive sizes in the same manner, or through different strategies. We perform multi-element histological analyses on a phylogenetically broad dataset sampled from eight theropod families, with a focus on gigantic tyrannosaurids and carcharodontosaurids, to reconstruct the growth strategies of these lineages and test if particular bones consistently preserve the most complete growth record. We find that in skeletally mature gigantic theropods, weight-bearing bones consistently preserve extensive growth records, whereas non-weight-bearing bones are remodelled and less useful for growth reconstruction, contrary to the pattern observed in smaller theropods and some other dinosaur clades. We find a heterochronic pattern of growth fitting an acceleration model in tyrannosaurids, with allosauroid carcharodontosaurids better fitting a model of hypermorphosis. These divergent growth patterns appear phylogenetically constrained, representing extreme versions of the growth patterns present in smaller coelurosaurs and allosauroids, respectively. This provides the first evidence of a lack of strong mechanistic or physiological constraints on size evolution in the largest bipeds in the fossil record and evidence of one of the longest-living individual dinosaurs ever documented.

@article{doi101098rspb20202258,
    author = "Cullen, Thomas M. and Canale, Juan I. and Apesteguı́a, Sebastián and Smith, Nathan D. and Hu, Dongyu and Makovicky, Peter J.",
    title = "Osteohistological analyses reveal diverse strategies of theropod dinosaur body-size evolution",
    year = "2020",
    journal = "Proceedings of the Royal Society B Biological Sciences",
    abstract = "The independent evolution of gigantism among dinosaurs has been a topic of long-standing interest, but it remains unclear if gigantic theropods, the largest bipeds in the fossil record, all achieved massive sizes in the same manner, or through different strategies. We perform multi-element histological analyses on a phylogenetically broad dataset sampled from eight theropod families, with a focus on gigantic tyrannosaurids and carcharodontosaurids, to reconstruct the growth strategies of these lineages and test if particular bones consistently preserve the most complete growth record. We find that in skeletally mature gigantic theropods, weight-bearing bones consistently preserve extensive growth records, whereas non-weight-bearing bones are remodelled and less useful for growth reconstruction, contrary to the pattern observed in smaller theropods and some other dinosaur clades. We find a heterochronic pattern of growth fitting an acceleration model in tyrannosaurids, with allosauroid carcharodontosaurids better fitting a model of hypermorphosis. These divergent growth patterns appear phylogenetically constrained, representing extreme versions of the growth patterns present in smaller coelurosaurs and allosauroids, respectively. This provides the first evidence of a lack of strong mechanistic or physiological constraints on size evolution in the largest bipeds in the fossil record and evidence of one of the longest-living individual dinosaurs ever documented.",
    url = "https://doi.org/10.1098/rspb.2020.2258",
    doi = "10.1098/rspb.2020.2258",
    openalex = "W3110230871",
    references = "doi101016jcub201408034, doi101017s0094837300006588, doi101017s0094837300021308, doi101029sc005p0175, doi101038nature02699, doi101038ncomms3827, doi101073pnas0708903105, doi101098rspb20122526, doi101126sciadvaax6250, doi101126science1225376, doi101126science1258750, doi101146annurevearth060313054858, doi101186174170071060, doi101186s1289801601068, doi101371journalpone0033539, doi1016710272463420000200115lbhoth20co2, doi10560219780801881206, doi105860choice490282, erickson2014on"
}

Inferring the body mass of fossil taxa, such as non-avian dinosaurs, provides a powerful tool for interpreting physiological and ecological properties, as well as the ability to study these traits through deep time and within a macroevolutionary context. As a result, over the past 100 years a number of studies advanced methods for estimating mass in dinosaurs and other extinct taxa. These methods can be categorized into two major approaches: volumetric-density (VD) and extant-scaling (ES). The former receives the most attention in non-avian dinosaurs and advanced appreciably over the last century: from initial physical scale models to three-dimensional (3D) virtual techniques that utilize scanned data obtained from entire skeletons. The ES approach is most commonly applied to extinct members of crown clades but some equations are proposed and utilized in non-avian dinosaurs. Because both approaches share a common goal, they are often viewed in opposition to one another. However, current palaeobiological research problems are often approach specific and, therefore, the decision to utilize a VD or ES approach is largely question dependent. In general, biomechanical and physiological studies benefit from the full-body reconstruction provided through a VD approach, whereas large-scale evolutionary and ecological studies require the extensive data sets afforded by an ES approach. This study summarizes both approaches to body mass estimation in stem-group taxa, specifically non-avian dinosaurs, and provides a comparative quantitative framework to reciprocally illuminate and corroborate VD and ES approaches. The results indicate that mass estimates are largely consistent between approaches: 73% of VD reconstructions occur within the expected 95% prediction intervals of the ES relationship. However, almost three quarters of outliers occur below the lower 95% prediction interval, indicating that VD mass estimates are, on average, lower than would be expected given their stylopodial circumferences. Inconsistencies (high residual and per cent prediction deviation values) are recovered to a varying degree among all major dinosaurian clades along with an overall tendency for larger deviations between approaches among small-bodied taxa. Nonetheless, our results indicate a strong corroboration between recent iterations of the VD approach based on 3D specimen scans suggesting that our current understanding of size in dinosaurs, and hence its biological correlates, has improved over time. We advance that VD and ES approaches have fundamentally (metrically) different advantages and, hence, the comparative framework used and advocated here combines the accuracy afforded by ES with the precision provided by VD and permits the rapid identification of discrepancies with the potential to open new areas of discussion.

@article{doi101111brv12638,
    author = "Campione, Nicolás E. and Evans, David C.",
    title = "The accuracy and precision of body mass estimation in non‐avian dinosaurs",
    year = "2020",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    abstract = "Inferring the body mass of fossil taxa, such as non-avian dinosaurs, provides a powerful tool for interpreting physiological and ecological properties, as well as the ability to study these traits through deep time and within a macroevolutionary context. As a result, over the past 100 years a number of studies advanced methods for estimating mass in dinosaurs and other extinct taxa. These methods can be categorized into two major approaches: volumetric-density (VD) and extant-scaling (ES). The former receives the most attention in non-avian dinosaurs and advanced appreciably over the last century: from initial physical scale models to three-dimensional (3D) virtual techniques that utilize scanned data obtained from entire skeletons. The ES approach is most commonly applied to extinct members of crown clades but some equations are proposed and utilized in non-avian dinosaurs. Because both approaches share a common goal, they are often viewed in opposition to one another. However, current palaeobiological research problems are often approach specific and, therefore, the decision to utilize a VD or ES approach is largely question dependent. In general, biomechanical and physiological studies benefit from the full-body reconstruction provided through a VD approach, whereas large-scale evolutionary and ecological studies require the extensive data sets afforded by an ES approach. This study summarizes both approaches to body mass estimation in stem-group taxa, specifically non-avian dinosaurs, and provides a comparative quantitative framework to reciprocally illuminate and corroborate VD and ES approaches. The results indicate that mass estimates are largely consistent between approaches: 73\% of VD reconstructions occur within the expected 95\% prediction intervals of the ES relationship. However, almost three quarters of outliers occur below the lower 95\% prediction interval, indicating that VD mass estimates are, on average, lower than would be expected given their stylopodial circumferences. Inconsistencies (high residual and per cent prediction deviation values) are recovered to a varying degree among all major dinosaurian clades along with an overall tendency for larger deviations between approaches among small-bodied taxa. Nonetheless, our results indicate a strong corroboration between recent iterations of the VD approach based on 3D specimen scans suggesting that our current understanding of size in dinosaurs, and hence its biological correlates, has improved over time. We advance that VD and ES approaches have fundamentally (metrically) different advantages and, hence, the comparative framework used and advocated here combines the accuracy afforded by ES with the precision provided by VD and permits the rapid identification of discrepancies with the potential to open new areas of discussion.",
    url = "https://doi.org/10.1111/brv.12638",
    doi = "10.1111/brv.12638",
    openalex = "W3082346069",
    references = "doi101016jcub201706071, doi101016jpalaeo201206027, doi101017cbo9780511608551, doi101038417070a, doi101038srep06196, doi101086303327, doi101098rsbl20120263, doi101098rspb20060443, doi101098rspb20171219, doi1011112041210x12226, doi101111evo12150, doi101111j17447429200700272x, doi101111j2041210x201100153x, doi101111pala12329, doi101126science1061967, doi101152physrev1947274511, doi101371journalpone0044318, doi101371journalpone0051925, doi101371journalpone0081917, doi101371journalpone0082000, doi107717peerj857, openalexw1558456135, openalexw195142154, openalexw2593733766, openalexw260994251, pontzer2009biomechanics"
}

Morphology forms the most fundamental level of data in vertebrate palaeontology because it is through interpretations of morphology that taxa are identified, creating the basis for broad evolutionary and palaeobiological hypotheses. Assessing maturity is one of the most basic aspects of morphological interpretation and provides the means to study the evolution of ontogenetic changes, population structure and palaeoecology, life-history strategies, and heterochrony along evolutionary lineages that would otherwise be lost to time. Saurian reptiles (the least-inclusive clade containing Lepidosauria and Archosauria) have remained an incredibly diverse, numerous, and disparate clade through their ~260-million-year history. Because of the great disparity in this group, assessing maturity of saurian reptiles is difficult, fraught with methodological and terminological ambiguity. We compiled a novel database of literature, assembling >900 individual instances of saurian maturity assessment, to examine critically how saurian maturity has been diagnosed. We review the often inexact and inconsistent terminology used in saurian maturity assessment (e.g. 'juvenile', 'mature') and provide routes for better clarity and cross-study coherence. We describe the various methods that have been used to assess maturity in every major saurian group, integrating data from both extant and extinct taxa to give a full account of the current state of the field and providing method-specific pitfalls, best practices, and fruitful directions for future research. We recommend that a new standard subsection, 'Ontogenetic Assessment', be added to the Systematic Palaeontology portions of descriptive studies to provide explicit ontogenetic diagnoses with clear criteria. Because the utility of different ontogenetic criteria is highly subclade dependent among saurians, even for widely used methods (e.g. neurocentral suture fusion), we recommend that phylogenetic context, preferably in the form of a phylogenetic bracket, be used to justify the use of a maturity assessment method. Different methods should be used in conjunction as independent lines of evidence when assessing maturity, instead of an ontogenetic diagnosis resting entirely on a single criterion, which is common in the literature. Critically, there is a need for data from extant taxa with well-represented growth series to be integrated with the fossil record to ground maturity assessments of extinct taxa in well-constrained, empirically tested methods.

@article{doi101111brv12666,
    author = "Griffin, Christopher T. and Stocker, Michelle R. and Colleary, Caitlin and Stefanic, Candice M. and Lessner, Emily J. and Riegler, Mitchell and Formoso, Kiersten K. and Koeller, Krista Leslie Marie and Nesbitt, Sterling J.",
    title = "Assessing ontogenetic maturity in extinct saurian reptiles",
    year = "2020",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    abstract = "Morphology forms the most fundamental level of data in vertebrate palaeontology because it is through interpretations of morphology that taxa are identified, creating the basis for broad evolutionary and palaeobiological hypotheses. Assessing maturity is one of the most basic aspects of morphological interpretation and provides the means to study the evolution of ontogenetic changes, population structure and palaeoecology, life-history strategies, and heterochrony along evolutionary lineages that would otherwise be lost to time. Saurian reptiles (the least-inclusive clade containing Lepidosauria and Archosauria) have remained an incredibly diverse, numerous, and disparate clade through their \textasciitilde 260-million-year history. Because of the great disparity in this group, assessing maturity of saurian reptiles is difficult, fraught with methodological and terminological ambiguity. We compiled a novel database of literature, assembling >900 individual instances of saurian maturity assessment, to examine critically how saurian maturity has been diagnosed. We review the often inexact and inconsistent terminology used in saurian maturity assessment (e.g. 'juvenile', 'mature') and provide routes for better clarity and cross-study coherence. We describe the various methods that have been used to assess maturity in every major saurian group, integrating data from both extant and extinct taxa to give a full account of the current state of the field and providing method-specific pitfalls, best practices, and fruitful directions for future research. We recommend that a new standard subsection, 'Ontogenetic Assessment', be added to the Systematic Palaeontology portions of descriptive studies to provide explicit ontogenetic diagnoses with clear criteria. Because the utility of different ontogenetic criteria is highly subclade dependent among saurians, even for widely used methods (e.g. neurocentral suture fusion), we recommend that phylogenetic context, preferably in the form of a phylogenetic bracket, be used to justify the use of a maturity assessment method. Different methods should be used in conjunction as independent lines of evidence when assessing maturity, instead of an ontogenetic diagnosis resting entirely on a single criterion, which is common in the literature. Critically, there is a need for data from extant taxa with well-represented growth series to be integrated with the fossil record to ground maturity assessments of extinct taxa in well-constrained, empirically tested methods.",
    url = "https://doi.org/10.1111/brv.12666",
    doi = "10.1111/brv.12666",
    openalex = "W3106975553",
    references = "chinsamy1998polar, deevey1947life, deklerk2000a, doi101002ar20972, doi101002ar20982, doi101002ar20991, doi101002ar24099, doi101002ar24130, doi101002jez513, doi101002jmor10406, doi1010079780387981413, doi1010079783319242774, doi101007bf02988144, doi101007s0011401208891, doi101007s0011401209171, doi101016jannpal200803002, doi101016jcub201609040, doi101016jcub201610043, doi101016jpalaeo200901002, doi101016jpalaeo201206027, doi101016jtree200508012, doi101016s0753396903000053, doi101016s1631069102014294, doi101017cbo9780511608377010, doi101017pab201519, doi101017s0094837300012331, doi101017s0094837300021308, doi10103832884, doi101038nature01657, doi101038nature04633, doi101038nature11146, doi101038nature12168, doi101038nature13467, doi101038srep20252, doi101038srep44942, doi101073pnas0708903105, doi101073pnas1203238109, doi101073pnas1613813113, doi101073pnas932514623, doi10108002724634199510011271, doi10108002724634199910011160, doi101080027246342010483632, doi101080027246342011557116, doi101080027246342013820113, doi1010800272463420161111224, doi101080147720192010484650, doi101086395888, doi101086653688, doi101093icbicw069, doi101093sysbiosyw033, doi101098rsbl20070254, doi101098rsbl20090310, doi101098rsbl20150947, doi101098rspb20042829, doi101098rspb20110410, doi101098rstb20190136, doi1011112041210x12226, doi101111evo13382, doi101111j109636421997tb00340x, doi101111j109636422000tb02201x, doi101111j10963642200400130x, doi101111j10963642200600232x, doi101111j10963642201000620x, doi101111j136520281973tb00081x, doi101111j136529071972tb00160x, doi101111j15023931201100300x, doi101111j174966321940tb57047x, doi101111j216409471940tb00068x, doi101111joa12719, doi101111joa12775, doi101111zoj12193, doi101126sciadv1501080, doi101126sciadvaax6250, doi101126science1225376, doi101146annurevearth060313054858, doi101146annurevecolsys151393, doi101146annureves15110184002141, doi101186174170071060, doi1012060003009020042860001mptaso20co2, doi1012060003009020073021taoeoa20co2, doi101242jeb00841, doi101371journalpone0007390, doi101371journalpone0007626, doi101371journalpone0011613, doi101371journalpone0012292, doi101371journalpone0013120, doi101371journalpone0021376, doi101371journalpone0025186, doi101371journalpone0029958, doi101371journalpone0032623, doi101371journalpone0033539, doi101371journalpone0044318, doi101371journalpone0080405, doi101371journalpone0081917, doi101371journalpone0121476, doi101371journalpone0141304, doi101371journalpone0158334, doi101371journalpone0175253, doi101371journalpone0204007, doi1015468gcrned, doi101590s000137652011000100005, doi1016660094837320030290243vpasat20co2, doi1016660094837320050310291teafot20co2, doi1016660094837320080340247ositlb20co2, doi1016690883135120010160482ttoaco20co2, doi1016710272463420040240555gisdap20co2, doi10167102724634200727127tpasom20co2, doi10167102724634200727350asoitp20co2, doi10167102724634200828134ooceit20co2, doi1016710390290119, doi1016710390290218, doi1017161paleo180818764, doi102110palo2003p0322, doi102110palo2009p09103r, doi102110palo2017076, doi1023071292217, doi1023073514695, doi1031610680390210, doi105281zenodo16228320, doi10560219780801881206, doi105710amgh040820173100, doi105860choice434677, doi105860choice490282, doi105962bhltitle7369, doi107717peerj4558, doi107717peerj5976, doi107717peerj7247, doi107717peerj7764, erickson2014on, houck1990allometric, martinsander2006bone, nesbitt2009a, nesbitt2013the, openalexw1565584485, openalexw2259418280, openalexw2506868775, openalexw3210282143, openalexw51761775, zhao2019ontogenetic"
}

Abstract Spatiotemporal changes in fossil specimen completeness can bias our understanding of a group's evolutionary history. The quality of the sauropodomorph fossil record was assessed a decade ago, but the number of valid species has since increased by 60%, and 17% of the taxa from that study have since undergone taxonomic revision. Here, we assess how 10 years of additional research has changed our outlook on the group's fossil record. We quantified the completeness of all 307 sauropodomorph species currently considered valid using the skeletal completeness metric, which calculates the proportion of a complete skeleton preserved for each taxon. Taxonomic and stratigraphic age revisions, rather than new species, are the drivers of the most significant differences between the current results and those of the previous assessment. No statistical differences appeared when we use our new dataset to generate temporal completeness curves based solely on taxa known in 2009 or 1999. We now observe a severe drop in mean completeness values across the Jurassic–Cretaceous boundary that never recovers to pre‐Cretaceous levels. Explaining this pattern is difficult, as we find no convincing evidence that it is related to environmental preferences or body size changes. Instead, it might result from: (1) reduction of terrestrial fossil preservation space due to sea level rise; (2) ecological specificities and relatively high diagnosability of Cretaceous species; and/or (3) increased sampling of newly explored sites with many previously unknown taxa. Revisiting patterns in this manner allows us to test the longevity of conclusions made in previous quantitative studies.

@article{doi101111pala12496,
    author = "Cashmore, Daniel D. and Mannion, Philip D. and Upchurch, Paul and Butler, Richard J.",
    title = "Ten more years of discovery: revisiting the quality of the sauropodomorph dinosaur fossil record",
    year = "2020",
    journal = "Palaeontology",
    abstract = "Abstract Spatiotemporal changes in fossil specimen completeness can bias our understanding of a group's evolutionary history. The quality of the sauropodomorph fossil record was assessed a decade ago, but the number of valid species has since increased by 60\%, and 17\% of the taxa from that study have since undergone taxonomic revision. Here, we assess how 10 years of additional research has changed our outlook on the group's fossil record. We quantified the completeness of all 307 sauropodomorph species currently considered valid using the skeletal completeness metric, which calculates the proportion of a complete skeleton preserved for each taxon. Taxonomic and stratigraphic age revisions, rather than new species, are the drivers of the most significant differences between the current results and those of the previous assessment. No statistical differences appeared when we use our new dataset to generate temporal completeness curves based solely on taxa known in 2009 or 1999. We now observe a severe drop in mean completeness values across the Jurassic–Cretaceous boundary that never recovers to pre‐Cretaceous levels. Explaining this pattern is difficult, as we find no convincing evidence that it is related to environmental preferences or body size changes. Instead, it might result from: (1) reduction of terrestrial fossil preservation space due to sea level rise; (2) ecological specificities and relatively high diagnosability of Cretaceous species; and/or (3) increased sampling of newly explored sites with many previously unknown taxa. Revisiting patterns in this manner allows us to test the longevity of conclusions made in previous quantitative studies.",
    url = "https://doi.org/10.1111/pala.12496",
    doi = "10.1111/pala.12496",
    openalex = "W3017772092",
    references = "doi1010079780387981413, doi1010079783319242774, doi101016jjsames201411008, doi101016jpalaeo200901002, doi101016jpalaeo200906004, doi101016s0016787876800077, doi101038s41467018051281, doi101038s41467019089972, doi101046j14209101200200472x, doi101073pnas1521478113, doi10108008912969009386535, doi101093bioinformaticsbty633, doi101093zoolinneanzlx103, doi101093zoolinneanzly009, doi101093zoolinneanzly068, doi101098rsbl20180431, doi101098rspb20122526, doi101111brv12255, doi101111j2041210x201100169x, doi101111j2041210x201200196x, doi101111j251761611995tb02031x, doi101126science1105113, doi101126science23547931156, doi101371journalpone0078573, openalexw2611511275"
}

Abstract Whilst bones present a static view of extinct animals, fossil footprints are a direct record of the activity and motion of the track maker. Deep footprints are a particularly good record of foot motion. Such footprints rarely look like the feet that made them; the sediment being heavily disturbed by the foot motion. Because of this, such tracks are often overlooked or dismissed in preference for more foot‐like impressions. However, the deeper the foot penetrates the substrate, the more motion is captured in the sediment volume. We have used deep, penetrative, Jurassic dinosaur tracks which have been naturally split into layers, to reconstruct foot motions of animals living over 200 million years ago. We consider these reconstructions to be hypotheses of motion. To test these hypotheses, we use the Discrete Element Method, in which individual particles of substrate are simulated in response to a penetrating foot model. Simulations that produce virtual tracks morphologically similar to the fossils lend support to the motion being plausible, while simulations that result in very different final tracks serve to reject the hypothesis of motion and help generate a new hypothesis.

@article{doi101111pala12502,
    author = "Falkingham, Peter and Turner, Morgan L. and Gatesy, Stephen M.",
    title = "Constructing and testing hypotheses of dinosaur foot motions from fossil tracks using digitization and simulation",
    year = "2020",
    journal = "Palaeontology",
    abstract = "Abstract Whilst bones present a static view of extinct animals, fossil footprints are a direct record of the activity and motion of the track maker. Deep footprints are a particularly good record of foot motion. Such footprints rarely look like the feet that made them; the sediment being heavily disturbed by the foot motion. Because of this, such tracks are often overlooked or dismissed in preference for more foot‐like impressions. However, the deeper the foot penetrates the substrate, the more motion is captured in the sediment volume. We have used deep, penetrative, Jurassic dinosaur tracks which have been naturally split into layers, to reconstruct foot motions of animals living over 200 million years ago. We consider these reconstructions to be hypotheses of motion. To test these hypotheses, we use the Discrete Element Method, in which individual particles of substrate are simulated in response to a penetrating foot model. Simulations that produce virtual tracks morphologically similar to the fossils lend support to the motion being plausible, while simulations that result in very different final tracks serve to reject the hypothesis of motion and help generate a new hypothesis.",
    url = "https://doi.org/10.1111/pala.12502",
    doi = "10.1111/pala.12502",
    openalex = "W3051929819",
    references = "coombs1980swimming, doi101002jez589, doi1010079783540472261, doi1010079789400904095, doi101016s001669958880038x, doi101073pnas1416252111, doi1010800272463420171314298, doi1010800272463420201781142, doi1010801042094020171350856, doi10108809650393181015012, doi101109cvpr20115995693, doi101111jzo12110, doi101111pala12373, doi101130g23452a1, doi1023073514816, doi1026879264, openalexw2294506137, openalexw2593733766, openalexw2619609965"
}

High numbers of spinosaurid teeth found in Morocco suggest that this clade was very abundant during the "Mid-"Cretaceous in northern Africa. Several reasons have been proposed to account for this abundance of spinosaur teeth, from sampling biases to ecology. However, the number of teeth in the fossil record also depends strongly on the tooth replacement rate. So far, little is known about the tooth formation time and replacement rates in spinosaurids. Here, we analysed the histology of several spinosaur teeth to estimate tooth formation time and replacement rates, using the count of lines of von Ebner, the daily formed incremental lines in the dentine of the teeth. Line counts indicated a maximum tooth formation time of 271 days, and replacement rates were predicted to be between 59 and 68 days. These rates are faster than in other large theropods for which data are known, and, together with the rather high number of teeth in a spinosaurid dentition, might thus help to explain the abundance of spinosaur teeth in the "Mid-"Cretaceous of northern Africa.

@article{doi10268791041,
    author = "Heckeberg, Nicola S. and Rauhut, Oliver W. M.",
    title = "Histology of spinosaurid dinosaur teeth from the Albian-Cenomanian of Morocco: Implications for tooth replacement and ecology",
    year = "2020",
    journal = "Palaeontologia Electronica",
    abstract = {High numbers of spinosaurid teeth found in Morocco suggest that this clade was very abundant during the "Mid-"Cretaceous in northern Africa. Several reasons have been proposed to account for this abundance of spinosaur teeth, from sampling biases to ecology. However, the number of teeth in the fossil record also depends strongly on the tooth replacement rate. So far, little is known about the tooth formation time and replacement rates in spinosaurids. Here, we analysed the histology of several spinosaur teeth to estimate tooth formation time and replacement rates, using the count of lines of von Ebner, the daily formed incremental lines in the dentine of the teeth. Line counts indicated a maximum tooth formation time of 271 days, and replacement rates were predicted to be between 59 and 68 days. These rates are faster than in other large theropods for which data are known, and, together with the rather high number of teeth in a spinosaurid dentition, might thus help to explain the abundance of spinosaur teeth in the "Mid-"Cretaceous of northern Africa.},
    url = "https://doi.org/10.26879/1041",
    doi = "10.26879/1041",
    openalex = "W3092489483",
    references = "doi101002ara20206, doi101016jjafrearsci200912007, doi101038s4159802066261w, doi101073pnas932514623, doi101080027246342015982797, doi101080147720192011630927, doi101126science1258750, doi101126science28253921298, doi101371journalpone0001230, doi101371journalpone0069235, doi101371journalpone0224734, doi105281zenodo16492064, doi107717peerj4129, johnston1979growth"
}

The unexpected discovery of non-avian dinosaurs from Arctic and Antarctic settings has generated considerable debate about whether they had the capacity to reproduce at high latitudes-especially the larger-bodied, hypothetically migratory taxa. Evidence for dinosaurian polar reproduction remains very rare, particularly for species that lived at the highest paleolatitudes (>75°). Here we report the discovery of perinatal and very young dinosaurs from the highest known paleolatitude for the clade-the Cretaceous Prince Creek Formation (PCF) of northern Alaska. These data demonstrate Arctic reproduction in a diverse assemblage of large- and small-bodied ornithischian and theropod species. In terms of overall diversity, 70% of the known dinosaurian families, as well as avialans (birds), in the PCF are represented by perinatal individuals, the highest percentage for any North American Cretaceous formation. These findings, coupled with prolonged incubation periods, small neonate sizes, and short reproductive windows suggest most, if not all, PCF dinosaurs were nonmigratory year-round Arctic residents. Notably, we reconstruct an annual chronology of reproductive events for the ornithischian dinosaurs using refined paleoenvironmental/plant phenology data and new insights into dinosaur incubation periods. Seasonal resource limitations due to extended periods of winter darkness and freezing temperatures placed severe constraints on dinosaurian reproduction, development, and maintenance, suggesting these taxa showed polar-specific life history strategies, including endothermy.

@article{doi101016jcub202105041,
    author = "Druckenmiller, Patrick S and Erickson, Gregory M and Brinkman, Donald and Brown, Caleb M and Eberle, Jaelyn J",
    title = "Nesting at extreme polar latitudes by non-avian dinosaurs.",
    year = "2021",
    journal = "Current biology: CB",
    abstract = "The unexpected discovery of non-avian dinosaurs from Arctic and Antarctic settings has generated considerable debate about whether they had the capacity to reproduce at high latitudes-especially the larger-bodied, hypothetically migratory taxa. Evidence for dinosaurian polar reproduction remains very rare, particularly for species that lived at the highest paleolatitudes (>75°). Here we report the discovery of perinatal and very young dinosaurs from the highest known paleolatitude for the clade-the Cretaceous Prince Creek Formation (PCF) of northern Alaska. These data demonstrate Arctic reproduction in a diverse assemblage of large- and small-bodied ornithischian and theropod species. In terms of overall diversity, 70\% of the known dinosaurian families, as well as avialans (birds), in the PCF are represented by perinatal individuals, the highest percentage for any North American Cretaceous formation. These findings, coupled with prolonged incubation periods, small neonate sizes, and short reproductive windows suggest most, if not all, PCF dinosaurs were nonmigratory year-round Arctic residents. Notably, we reconstruct an annual chronology of reproductive events for the ornithischian dinosaurs using refined paleoenvironmental/plant phenology data and new insights into dinosaur incubation periods. Seasonal resource limitations due to extended periods of winter darkness and freezing temperatures placed severe constraints on dinosaurian reproduction, development, and maintenance, suggesting these taxa showed polar-specific life history strategies, including endothermy.",
    url = "https://pubmed.ncbi.nlm.nih.gov/34171301/",
    doi = "10.1016/j.cub.2021.05.041",
    openalex = "W3174184361",
    pmid = "34171301",
    references = "doi101017s1477201907002271, doi101029sc005p0175, doi101038385247a0, doi101038nature01342, doi101038nature02699, doi101038nature02855, doi10113008137233291, doi101130spe332, doi101139cjes20200169, doi1012703p639, doi1016710272463420000200115lbhoth20co2, doi104202app001522015"
}

Dinosaurs dominated Mesozoic terrestrial ecosystems globally. However, whereas a pole-to-pole geographic distribution characterized ornithischians and theropods, sauropods were restricted to lower latitudes. Here, we evaluate the role of climate in shaping these biogeographic patterns through the Jurassic-Cretaceous (201-66 mya), combining dinosaur fossil occurrences, past climate data from Earth System models, and habitat suitability modeling. Results show that, uniquely among dinosaurs, sauropods occupied climatic niches characterized by high temperatures and strongly bounded by minimum cold temperatures. This constrained the distribution and dispersal pathways of sauropods to tropical areas, excluding them from latitudinal extremes, especially in the Northern Hemisphere. The greater availability of suitable habitat in the southern continents, particularly in the Late Cretaceous, might be key to explaining the high diversity of sauropods there, relative to northern landmasses. Given that ornithischians and theropods show a flattened or bimodal latitudinal biodiversity gradient, with peaks at higher latitudes, the closer correspondence of sauropods to a subtropical concentration could hint at fundamental thermophysiological differences to the other two clades.

@article{doi101016jcub202111061,
    author = "Chiarenza, Alfio Alessandro and Mannion, Philip D. and Farnsworth, Alex and Carrano, Matthew T. and Varela, Sara",
    title = "Climatic constraints on the biogeographic history of Mesozoic dinosaurs",
    year = "2021",
    journal = "Current Biology",
    abstract = "Dinosaurs dominated Mesozoic terrestrial ecosystems globally. However, whereas a pole-to-pole geographic distribution characterized ornithischians and theropods, sauropods were restricted to lower latitudes. Here, we evaluate the role of climate in shaping these biogeographic patterns through the Jurassic-Cretaceous (201-66 mya), combining dinosaur fossil occurrences, past climate data from Earth System models, and habitat suitability modeling. Results show that, uniquely among dinosaurs, sauropods occupied climatic niches characterized by high temperatures and strongly bounded by minimum cold temperatures. This constrained the distribution and dispersal pathways of sauropods to tropical areas, excluding them from latitudinal extremes, especially in the Northern Hemisphere. The greater availability of suitable habitat in the southern continents, particularly in the Late Cretaceous, might be key to explaining the high diversity of sauropods there, relative to northern landmasses. Given that ornithischians and theropods show a flattened or bimodal latitudinal biodiversity gradient, with peaks at higher latitudes, the closer correspondence of sauropods to a subtropical concentration could hint at fundamental thermophysiological differences to the other two clades.",
    url = "https://doi.org/10.1016/j.cub.2021.11.061",
    doi = "10.1016/j.cub.2021.11.061",
    openalex = "W4200184737",
    references = "alvarez1980extraterrestrial, cubo2020were, doi101002ar23306, doi101016jcub202105041, doi101016jjsames201411008, doi101017s0094837300007557, doi101038nature09670, doi101038s41467019089972, doi101038s4158602030114, doi101038s41598019517095, doi101073pnas0709472105, doi101073pnas2006087117, doi101073pnas2020778118, doi10108000401706196410490181, doi10108001621459195210483441, doi1010800311551820181453085, doi101093biomet4034237, doi1011112041210x12613, doi101111j20060906759004596x, doi101111pala12496, doi101111pala12514, doi101146annurevearth060313054858, doi101186147267851314, doi101371journalpone0012553, doi101371journalpone0235078, doi1018901119521, erickson2014on"
}

embryos are remarkably rare. Here we report an exceptionally preserved, articulated oviraptorid embryo inside an elongatoolithid egg, from the Late Cretaceous Hekou Formation of southern China. The head lies ventral to the body, with the feet on either side, and the back curled along the blunt pole of the egg, in a posture previously unrecognized in a non-avian dinosaur, but reminiscent of a late-stage modern bird embryo. Comparison to other late-stage oviraptorid embryos suggests that prehatch oviraptorids developed avian-like postures late in incubation, which in modern birds are related to coordinated embryonic movements associated with tucking - a behavior controlled by the central nervous system, critical for hatching success. We propose that such pre-hatching behavior, previously considered unique to birds, may have originated among non-avian theropods, which can be further investigated with additional discoveries of embryo fossils.

@article{doi101016jisci2021103516,
    author = "Xing, Lida and Niu, Kecheng and Ma, Waisum and Zelenitsky, Darla K. and Yang, Tzu-Ruei and Brusatte, Stephen L.",
    title = "An exquisitely preserved in-ovo theropod dinosaur embryo sheds light on avian-like prehatching postures",
    year = "2021",
    journal = "iScience",
    abstract = "embryos are remarkably rare. Here we report an exceptionally preserved, articulated oviraptorid embryo inside an elongatoolithid egg, from the Late Cretaceous Hekou Formation of southern China. The head lies ventral to the body, with the feet on either side, and the back curled along the blunt pole of the egg, in a posture previously unrecognized in a non-avian dinosaur, but reminiscent of a late-stage modern bird embryo. Comparison to other late-stage oviraptorid embryos suggests that prehatch oviraptorids developed avian-like postures late in incubation, which in modern birds are related to coordinated embryonic movements associated with tucking - a behavior controlled by the central nervous system, critical for hatching success. We propose that such pre-hatching behavior, previously considered unique to birds, may have originated among non-avian theropods, which can be further investigated with additional discoveries of embryo fossils.",
    url = "https://doi.org/10.1016/j.isci.2021.103516",
    doi = "10.1016/j.isci.2021.103516",
    openalex = "W4200185644",
    references = "doi101038ncomms4788, doi1012060003009044011, doi101642auk152161, doi1033740140540102, lee2019a"
}

During the latest Cretaceous, the European Archipelago was characterized by highly fragmented landmasses hosting putative dwarfed, insular dinosaurs, claimed as fossil evidence of the "island rule". The Villaggio del Pescatore quarry (north-eastern Italy) stands as the most informative locality within the palaeo-Mediterranean region and represents the first, multi-individual Konservat-Lagerstätte type dinosaur-bearing locality in Italy. The site is here critically re-evaluated as early Campanian in age, thus preceding the final fragmentation stages of the European Archipelago, including all other European localities preserving hypothesized dwarfed taxa. New skeletal remains allowed osteohistological analyses on the hadrosauroid Tethyshadros insularis indicating subadult features in the type specimen whereas a second, herein newly described, larger individual is likely somatically mature. A phylogenetic comparative framework places the body-size of T. insularis in range with other non-hadrosaurid Eurasian hadrosauroids, rejecting any significant evolutionary trend towards miniaturisation in this clade, confuting its 'pygmy' status, and providing unmatched data to infer environmentally-driven body-size trends in Mesozoic dinosaurs.

@article{doi101038s4159802102490x,
    author = "Chiarenza, Alfio Alessandro and Fabbri, Matteo and Consorti, Lorenzo and Muscioni, Marco and Evans, David C. and Cantalapiedra, Juan L. and Fanti, Federico",
    title = "An Italian dinosaur Lagerstätte reveals the tempo and mode of hadrosauriform body size evolution",
    year = "2021",
    journal = "Scientific Reports",
    abstract = {During the latest Cretaceous, the European Archipelago was characterized by highly fragmented landmasses hosting putative dwarfed, insular dinosaurs, claimed as fossil evidence of the "island rule". The Villaggio del Pescatore quarry (north-eastern Italy) stands as the most informative locality within the palaeo-Mediterranean region and represents the first, multi-individual Konservat-Lagerstätte type dinosaur-bearing locality in Italy. The site is here critically re-evaluated as early Campanian in age, thus preceding the final fragmentation stages of the European Archipelago, including all other European localities preserving hypothesized dwarfed taxa. New skeletal remains allowed osteohistological analyses on the hadrosauroid Tethyshadros insularis indicating subadult features in the type specimen whereas a second, herein newly described, larger individual is likely somatically mature. A phylogenetic comparative framework places the body-size of T. insularis in range with other non-hadrosaurid Eurasian hadrosauroids, rejecting any significant evolutionary trend towards miniaturisation in this clade, confuting its 'pygmy' status, and providing unmatched data to infer environmentally-driven body-size trends in Mesozoic dinosaurs.},
    url = "https://doi.org/10.1038/s41598-021-02490-x",
    doi = "10.1038/s41598-021-02490-x",
    openalex = "W3217018976",
    references = "doi101016jcretres2021104919, doi101038ncomms12931, doi101111brv12638"
}

Spinosaurids are among the most distinctive and yet poorly-known of large-bodied theropod dinosaurs, a situation exacerbated by their mostly fragmentary fossil record and competing views regarding their palaeobiology. Here, we report two new Early Cretaceous spinosaurid specimens from the Wessex Formation (Barremian) of the Isle of Wight. Large-scale phylogenetic analyses using parsimony and Bayesian techniques recover the pair in a new clade within Baryonychinae that also includes the hypodigm of the African spinosaurid Suchomimus. Both specimens represent distinct and novel taxa, herein named Ceratosuchops inferodios gen. et sp. nov. and Riparovenator milnerae gen. et sp. nov. A palaeogeographic reconstruction suggests a European origin for Spinosauridae, with at least two dispersal events into Africa. These new finds provide welcome information on poorly sampled areas of spinosaurid anatomy, suggest that sympatry was present and potentially common in baryonychines and spinosaurids as a whole, and contribute to updated palaeobiogeographic reconstructions for the clade.

@article{doi101038s41598021978708,
    author = "Barker, Chris T. and Hone, David W. E. and Naish, Darren and Cau, Andrea and Lockwood, Jeremy A. F. and Foster, Brian and Clarkin, Claire and Schneider, Philipp and Gostling, Neil J.",
    title = "New spinosaurids from the Wessex Formation (Early Cretaceous, UK) and the European origins of Spinosauridae",
    year = "2021",
    journal = "Scientific Reports",
    abstract = "Spinosaurids are among the most distinctive and yet poorly-known of large-bodied theropod dinosaurs, a situation exacerbated by their mostly fragmentary fossil record and competing views regarding their palaeobiology. Here, we report two new Early Cretaceous spinosaurid specimens from the Wessex Formation (Barremian) of the Isle of Wight. Large-scale phylogenetic analyses using parsimony and Bayesian techniques recover the pair in a new clade within Baryonychinae that also includes the hypodigm of the African spinosaurid Suchomimus. Both specimens represent distinct and novel taxa, herein named Ceratosuchops inferodios gen. et sp. nov. and Riparovenator milnerae gen. et sp. nov. A palaeogeographic reconstruction suggests a European origin for Spinosauridae, with at least two dispersal events into Africa. These new finds provide welcome information on poorly sampled areas of spinosaurid anatomy, suggest that sympatry was present and potentially common in baryonychines and spinosaurids as a whole, and contribute to updated palaeobiogeographic reconstructions for the clade.",
    url = "https://doi.org/10.1038/s41598-021-97870-8",
    doi = "10.1038/s41598-021-97870-8",
    openalex = "W3203271713",
    references = "doi101016jcretres201103005, doi101038s4159802066261w, doi101073pnas1613813113, doi1010800272463420201877151, doi101111brv12666, doi104202app20110144, doi107717peerj5976, doi107717peerj9192, sánchezhernández2007dinosaurs"
}

Mylodontidae (Mammalia, Xenarthra) is a family of ground sloths widely distributed in the South American fossil record, with members also present in Central and North America. Within the Mylodontidae, Lestodon armatus is the largest species, with an estimated body mass of more than three tonnes. This work focuses on the enlarged lower caniniforms of L. armatus as possibly exaggerated sexually dimorphic structures. Lower caniniforms from the late Pleistocene of Argentina, Uruguay, and Bolivia were studied using specimens from seven palaeontological collections. The possible sexual dimorphism in the caniniforms and its implications regarding the existence of sexual selection was assessed through morphometric analyses. The results support the existence of sexual dimorphism in L. armatus. Sexual dimorphism in an exaggerated structure in a large mammal suggests the existence of sexual selection, via competition between males or female mate choice, resulting in the evolution of the dimorphic structure. In L. armatus, the enlarged caniniforms would correspond to males and could have functioned as armaments in intraspecific fights or ornaments for sexual display. Based on observations in extant mammals, a polygynous mating system is proposed as highly probable in L. armatus, although the existence or composition of social groups cannot be certainly determined.

@article{doi1010800891296320211933470,
    author = "Varela, Luciano and McDonald, H. Gregory and Fariña, Richard A.",
    title = "Sexual dimorphism in the fossil ground sloth Lestodon armatus (Xenarthra, Folivora)",
    year = "2021",
    journal = "Historical Biology",
    abstract = "Mylodontidae (Mammalia, Xenarthra) is a family of ground sloths widely distributed in the South American fossil record, with members also present in Central and North America. Within the Mylodontidae, Lestodon armatus is the largest species, with an estimated body mass of more than three tonnes. This work focuses on the enlarged lower caniniforms of L. armatus as possibly exaggerated sexually dimorphic structures. Lower caniniforms from the late Pleistocene of Argentina, Uruguay, and Bolivia were studied using specimens from seven palaeontological collections. The possible sexual dimorphism in the caniniforms and its implications regarding the existence of sexual selection was assessed through morphometric analyses. The results support the existence of sexual dimorphism in L. armatus. Sexual dimorphism in an exaggerated structure in a large mammal suggests the existence of sexual selection, via competition between males or female mate choice, resulting in the evolution of the dimorphic structure. In L. armatus, the enlarged caniniforms would correspond to males and could have functioned as armaments in intraspecific fights or ornaments for sexual display. Based on observations in extant mammals, a polygynous mating system is proposed as highly probable in L. armatus, although the existence or composition of social groups cannot be certainly determined.",
    url = "https://doi.org/10.1080/08912963.2021.1933470",
    doi = "10.1080/08912963.2021.1933470",
    openalex = "W3168435035",
    references = "doi101093biolinneanblaa105"
}

Abundant and well-preserved fossil microbenthos occurs in siliciclastic deposits of all Earth ages, from the early Archean to today. Studies in modern settings show how microbenthos responds to sediment dynamics by baffling and trapping, binding, biostabilization, and growth. Results of this microbial-sediment interaction are microbially induced sedimentary structures (MISS). Successful prospection for rich MISS occurrences in the terrestrial lithological record requires unraveling genesis and taphonomy of MISS, both of which are defined only by a narrow range of specific conditions. These conditions have to coincide with high detectability which is a function of outcrop quality, bedding character, and rock type. Assertions on biogenicity of MISS morphologies must be based on the presence of microbially induced sedimentary textures (MIST), which are MISS-internal textures comprising replacement minerals arranged into microscopic biological morphologies, ancient carbonaceous matter, trace fossils, and geochemical signals. MISS serve as possible templates for the decryption of ancient life-processes on Mars. This article closes with a perspective on selected deposits and ancient environments in Meridiani Planum, Gale Crater, and Jezero Crater, Mars, regarding their potential for MISS occurrences. The earlier hypothesis of structures on Mars as potentially being MISS is revised.

@article{doi101089ast20210011,
    author = "Noffke, Nora",
    title = "Microbially Induced Sedimentary Structures in Clastic Deposits: Implication for the Prospection for Fossil Life on Mars",
    year = "2021",
    journal = "Astrobiology",
    abstract = "Abundant and well-preserved fossil microbenthos occurs in siliciclastic deposits of all Earth ages, from the early Archean to today. Studies in modern settings show how microbenthos responds to sediment dynamics by baffling and trapping, binding, biostabilization, and growth. Results of this microbial-sediment interaction are microbially induced sedimentary structures (MISS). Successful prospection for rich MISS occurrences in the terrestrial lithological record requires unraveling genesis and taphonomy of MISS, both of which are defined only by a narrow range of specific conditions. These conditions have to coincide with high detectability which is a function of outcrop quality, bedding character, and rock type. Assertions on biogenicity of MISS morphologies must be based on the presence of microbially induced sedimentary textures (MIST), which are MISS-internal textures comprising replacement minerals arranged into microscopic biological morphologies, ancient carbonaceous matter, trace fossils, and geochemical signals. MISS serve as possible templates for the decryption of ancient life-processes on Mars. This article closes with a perspective on selected deposits and ancient environments in Meridiani Planum, Gale Crater, and Jezero Crater, Mars, regarding their potential for MISS occurrences. The earlier hypothesis of structures on Mars as potentially being MISS is revised.",
    url = "https://doi.org/10.1089/ast.2021.0011",
    doi = "10.1089/ast.2021.0011",
    openalex = "W3164244887",
    references = "doi101016jearscirev2019102888, doi101016jearscirev2020103296, doi101016jprecamres201804007, doi102110jsr201957"
}

Paleopathological diagnoses provide key information on the macroevolutionary origin of disease as well as behavioral and physiological inferences that are inaccessible via direct observation of extinct organisms. Here we describe the external gross morphology and internal architecture of a pathologic right second metatarsal (MMNS VP-6332) of a large-bodied ornithomimid (~432 kg) from the Santonian (Upper Cretaceous) Eutaw Formation in Mississippi, using a combination of X-ray computed microtomography (microCT) and petrographic histological analyses. X-ray microCT imaging and histopathologic features are consistent with multiple complete, oblique to comminuted, minimally displaced mid-diaphyseal cortical fractures that produce a "butterfly" fragment fracture pattern, and secondary osteomyelitis with a bone fistula formation. We interpret this as evidence of blunt force trauma to the foot that could have resulted from intra- or interspecific competition or predator-prey interaction, and probably impaired the function of the metatarsal as a weight-bearing element until the animal's death. Of particular interest is the apparent decoupling of endosteal and periosteal pathological bone deposition in MMNS VP-6332, which produces transverse sections exhibiting homogenously thick endosteal pathological bone in the absence of localized periosteal reactive bone. These distribution and depositional patterns are used as criteria for ruling out a pathological origin in favor of a reproductive one for unusual endosteal bone in fossil specimens. On the basis of MMNS VP-6332, we suggest caution in their use to substantiate a medullary bone identification in extinct archosaurians.

@article{doi101002ar25069,
    author = "Chinzorig, Tsogtbaatar and Beguesse, Kyla A. and Canoville, Aurore and Phillips, George E. and Zanno, Lindsay E.",
    title = "Chronic fracture and osteomyelitis in a large‐bodied ornithomimosaur with implications for the identification of unusual endosteal bone in the fossil record",
    year = "2022",
    journal = "The Anatomical Record",
    abstract = {Paleopathological diagnoses provide key information on the macroevolutionary origin of disease as well as behavioral and physiological inferences that are inaccessible via direct observation of extinct organisms. Here we describe the external gross morphology and internal architecture of a pathologic right second metatarsal (MMNS VP-6332) of a large-bodied ornithomimid (\textasciitilde 432 kg) from the Santonian (Upper Cretaceous) Eutaw Formation in Mississippi, using a combination of X-ray computed microtomography (microCT) and petrographic histological analyses. X-ray microCT imaging and histopathologic features are consistent with multiple complete, oblique to comminuted, minimally displaced mid-diaphyseal cortical fractures that produce a "butterfly" fragment fracture pattern, and secondary osteomyelitis with a bone fistula formation. We interpret this as evidence of blunt force trauma to the foot that could have resulted from intra- or interspecific competition or predator-prey interaction, and probably impaired the function of the metatarsal as a weight-bearing element until the animal's death. Of particular interest is the apparent decoupling of endosteal and periosteal pathological bone deposition in MMNS VP-6332, which produces transverse sections exhibiting homogenously thick endosteal pathological bone in the absence of localized periosteal reactive bone. These distribution and depositional patterns are used as criteria for ruling out a pathological origin in favor of a reproductive one for unusual endosteal bone in fossil specimens. On the basis of MMNS VP-6332, we suggest caution in their use to substantiate a medullary bone identification in extinct archosaurians.},
    url = "https://doi.org/10.1002/ar.25069",
    doi = "10.1002/ar.25069",
    openalex = "W4301391236",
    references = "doi101038s41598022057613, doi101111joa13363"
}

Other than repaired fractures, osteoarthritis, and periosteal reaction, the vertebrate fossil record has limited evidence of non-osseous diseases. This difficulty in paleontological diagnoses stems from (1) the inability to conduct medical testing, (2) soft-tissue pathologic structures are less likely to be preserved, and (3) many osseous lesions are not diagnostically specific. However, here reported for the first time is an avian-style respiratory disorder in a non-avian dinosaur. This sauropod presents irregular bony pathologic structures stemming from the pneumatic features in the cervical vertebrae. As sauropods show well-understood osteological correlates indicating that respiratory tissues were incorporated into the post-cranial skeleton, and thus likely had an 'avian-style' form of respiration, it is most parsimonious to identify these pathologic structures as stemming from a respiratory infection. Although several extant avian infections produce comparable symptoms, the most parsimonious is airsacculitis with associated osteomyelitis. From actinobacterial to fungal in origin, airsacculitis is an extremely prevalent respiratory disorder in birds today. While we cannot pinpoint the specific infectious agent that caused the airsacculitis, this diagnosis establishes the first fossil record of this disease. Additionally, it allows us increased insight into the medical disorders of dinosaurs from a phylogenetic perspective and understanding what maladies plagued the "fearfully great lizards".

@article{doi101038s41598022057613,
    author = "Woodruff, D. Cary and Wolff, Ewan D. S. and Wedel, Mathew J. and Dennison, Sophie and Witmer, Lawrence M.",
    title = "The first occurrence of an avian-style respiratory infection in a non-avian dinosaur",
    year = "2022",
    journal = "Scientific Reports",
    abstract = {Other than repaired fractures, osteoarthritis, and periosteal reaction, the vertebrate fossil record has limited evidence of non-osseous diseases. This difficulty in paleontological diagnoses stems from (1) the inability to conduct medical testing, (2) soft-tissue pathologic structures are less likely to be preserved, and (3) many osseous lesions are not diagnostically specific. However, here reported for the first time is an avian-style respiratory disorder in a non-avian dinosaur. This sauropod presents irregular bony pathologic structures stemming from the pneumatic features in the cervical vertebrae. As sauropods show well-understood osteological correlates indicating that respiratory tissues were incorporated into the post-cranial skeleton, and thus likely had an 'avian-style' form of respiration, it is most parsimonious to identify these pathologic structures as stemming from a respiratory infection. Although several extant avian infections produce comparable symptoms, the most parsimonious is airsacculitis with associated osteomyelitis. From actinobacterial to fungal in origin, airsacculitis is an extremely prevalent respiratory disorder in birds today. While we cannot pinpoint the specific infectious agent that caused the airsacculitis, this diagnosis establishes the first fossil record of this disease. Additionally, it allows us increased insight into the medical disorders of dinosaurs from a phylogenetic perspective and understanding what maladies plagued the "fearfully great lizards".},
    url = "https://doi.org/10.1038/s41598-022-05761-3",
    doi = "10.1038/s41598-022-05761-3",
    openalex = "W4211081201",
    references = "doi101002ar23988, doi101002ar24218, doi101038114085a0, doi101038282296a0, doi101038nature08740, doi101038s415980160028x, doi101038s41598018371862, doi101038srep18952, doi10107997808519965610000, doi10108002724634199710011027, doi101111joa13363, doi101525california97805202462320010001, doi1016710272463420030230344teovpi20co2, doi107326000348199234604"
}

Fossil tracks are important palaeobiological data sources. The quantitative analysis of their shape, however, has been hampered by their high variability and lack of discrete margins and landmarks. We here present the first approach using deep convolutional neural networks (DCNNs) to study fossil tracks, overcoming the limitations of previous statistical approaches. We employ a DCNN to discriminate between theropod and ornithischian dinosaur tracks based on a total of 1372 outline silhouettes. The DCNN consistently outperformed human experts on an independent test set. We also used the DCNN to classify tracks of a large tridactyl trackmaker from Lark Quarry, Australia, the identity of which has been subject to intense debate. The presented approach can only be considered a first step towards the wider application of machine learning in fossil track research, which is not limited to classification problems. Current limitations, such as the subjectivity and information loss inherent in interpretive outlines, may be overcome in the future by training neural networks on three-dimensional models directly, though this will require an increased uptake in digitization among workers in the field.

@article{doi101098rsif20220588,
    author = "Lallensack, Jens N. and Romilio, Anthony and Falkingham, Peter",
    title = "A machine learning approach for the discrimination of theropod and ornithischian dinosaur tracks",
    year = "2022",
    journal = "Journal of The Royal Society Interface",
    abstract = "Fossil tracks are important palaeobiological data sources. The quantitative analysis of their shape, however, has been hampered by their high variability and lack of discrete margins and landmarks. We here present the first approach using deep convolutional neural networks (DCNNs) to study fossil tracks, overcoming the limitations of previous statistical approaches. We employ a DCNN to discriminate between theropod and ornithischian dinosaur tracks based on a total of 1372 outline silhouettes. The DCNN consistently outperformed human experts on an independent test set. We also used the DCNN to classify tracks of a large tridactyl trackmaker from Lark Quarry, Australia, the identity of which has been subject to intense debate. The presented approach can only be considered a first step towards the wider application of machine learning in fossil track research, which is not limited to classification problems. Current limitations, such as the subjectivity and information loss inherent in interpretive outlines, may be overcome in the future by training neural networks on three-dimensional models directly, though this will require an increased uptake in digitization among workers in the field.",
    url = "https://doi.org/10.1098/rsif.2022.0588",
    doi = "10.1098/rsif.2022.0588",
    openalex = "W4308679213",
    references = "doi1010800272463420171314298, doi1010800272463420201781142, doi101111jzo12110, doi101111pala12373, doi101111pala12449, doi101111pala12502, doi107717peerj2059"
}

Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.

@article{doi101111brv12829,
    author = "Hendrickx, Christophe and Bell, Phil R. and Pittman, Michael and Milner, Andrew R. and Cuesta, Elena and O’Connor, Jingmai K. and Loewen, Mark A. and Currie, Philip J. and Mateus, Octávio and Kaye, Thomas G. and Delcourt, Rafael",
    title = "Morphology and distribution of scales, dermal ossifications, and other non‐feather integumentary structures in non‐avialan theropod dinosaurs",
    year = "2022",
    journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society",
    abstract = "Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.",
    url = "https://doi.org/10.1111/brv.12829",
    doi = "10.1111/brv.12829",
    openalex = "W4206485050",
    references = "crossref1998encyclopedia, doi101002jmor10382, doi101016jcub201706071, doi101016jcub202006105, doi101016jgca201006017, doi101016s001678780180047x, doi101017jpa202014, doi10103831635, doi10103834356, doi10103835047056, doi101038ncomms14972, doi101038s41598018371862, doi101038srep44942, doi1010800272463420211897604, doi101080147720192013781067, doi101093biolinneanblaa105, doi101093zoolinneanzly009, doi101111brv12829, doi101111cla12160, doi101126science28454232137, doi1011270077774920100125, doi101146annurevearth060313054858, doi1012063521, doi101371journalpone0044012, doi101371journalpone0125819, doi1017161paleo180818764, doi1017161pc180818764, doi10230725058147, doi105962bhltitle5716, doi107717peerj4066, doi107717peerj7247, doi107717peerj7963, doi107717peerj9192, erickson2014on, openalexw1915591379, openalexw2619609965"
}

Abstract Current research suggests that the initial radiation of maniraptoran theropods occurred in the Middle Jurassic, although their fossil record is known almost exclusively from the Cretaceous. However, fossils of Jurassic maniraptorans are scarce, usually consisting solely of isolated teeth, and their identifications are often disputed. Here, we apply different machine learning models, in conjunction with morphological comparisons, to a suite of isolated theropod teeth from Bathonian microvertebrate sites in the UK to determine whether any of these can be confidently assigned to Maniraptora. We generated three independent models developed on a training dataset with a wide range of theropod taxa and broad geographical and temporal coverage. Classification of the Middle Jurassic teeth in our sample against these models and comparison of the morphology indicates the presence of at least three distinct dromaeosaur morphotypes, plus a therizinosaur and troodontid in these assemblages. These new referrals significantly extend the ranges of Therizinosauroidea and Troodontidae by some 27 myr. These results indicate that not only were maniraptorans present in the Middle Jurassic, as predicted by previous phylogenetic analyses, but they had already radiated into a diverse fauna that pre‐dated the break‐up of Pangaea. This study also demonstrates the power of machine learning to provide quantitative assessments of isolated teeth in providing a robust, testable framework for taxonomic identifications, and highlights the importance of assessing and including evidence from microvertebrate sites in faunal and evolutionary analyses.

@article{doi101002spp21487,
    author = "Wills, Simon and Underwood, Charlie J. and Barrett, Paul M.",
    title = "Machine learning confirms new records of maniraptoran theropods in Middle Jurassic UK microvertebrate faunas",
    year = "2023",
    journal = "Papers in Palaeontology",
    abstract = "Abstract Current research suggests that the initial radiation of maniraptoran theropods occurred in the Middle Jurassic, although their fossil record is known almost exclusively from the Cretaceous. However, fossils of Jurassic maniraptorans are scarce, usually consisting solely of isolated teeth, and their identifications are often disputed. Here, we apply different machine learning models, in conjunction with morphological comparisons, to a suite of isolated theropod teeth from Bathonian microvertebrate sites in the UK to determine whether any of these can be confidently assigned to Maniraptora. We generated three independent models developed on a training dataset with a wide range of theropod taxa and broad geographical and temporal coverage. Classification of the Middle Jurassic teeth in our sample against these models and comparison of the morphology indicates the presence of at least three distinct dromaeosaur morphotypes, plus a therizinosaur and troodontid in these assemblages. These new referrals significantly extend the ranges of Therizinosauroidea and Troodontidae by some 27 myr. These results indicate that not only were maniraptorans present in the Middle Jurassic, as predicted by previous phylogenetic analyses, but they had already radiated into a diverse fauna that pre‐dated the break‐up of Pangaea. This study also demonstrates the power of machine learning to provide quantitative assessments of isolated teeth in providing a robust, testable framework for taxonomic identifications, and highlights the importance of assessing and including evidence from microvertebrate sites in faunal and evolutionary analyses.",
    url = "https://doi.org/10.1002/spp2.1487",
    doi = "10.1002/spp2.1487",
    openalex = "W4365457719",
    references = "doi1010079783319242774, doi101023a1010933404324, doi101038nmeth2019, doi101111j251761611996tb02073x, doi101146annurevearth081320064052, doi1018637jssv077i01, doi1018901220101, doi105281zenodo16171435, openalexw273955616, openalexw4399271987, woodward1910on"
}

Abstract Dinosaur tracks are considerably common in the fossil record and were described from many areas in the world. They provide a live picture of dinosaur behaviour and offer valuable data about different aspects of the trackmaker paleobiology. The dinosaur ichnological record allows gain information about autopod anatomy, functional adaptations, stance and gaits with which dinosaurs moved. This information, which is often difficult to obtain from the body-fossil record alone, allows making inferences not only concerning the single individuals who produced the footprints, but also within an evolutionary context. Footprints provide also evidences about the abilities that dinosaurs had to swim, run or live with certain pathologies. They also allowed inferring how they move in herds or even made courtship rituals. The study of tracks also enables the reconstruction of paleocommunities including predator–prey interaction. On the other hand, footprints are useful paleoenvironmental indicators, informing about moisture content, bathymetry, paleocurrents, subaqueous substrates, zonations in lacustrine margins, etc. In addition, it has been proposed that dinosaur track assemblages can be related to certain facies (ichnofacies), in order to refine paleoenvironmental reconstructions. Dinosaur tracks can sometimes be in the shadow with respect to the skeletal record. However, the data obtained from the ichnological record complements and completes the knowledge we have about the life of dinosaurs, even showing previously unknown aspects. This work is an overview of the information we can obtain from the study of non-avian dinosaur footprints, trying to answer some questions about their life.

@article{doi101007s41513023002266,
    author = "Díaz‐Martínez, Ignacio and Citton, Paolo and Castanera, Diego",
    title = "What do their footprints tell us? Many questions and some answers about the life of non-avian dinosaurs",
    year = "2023",
    journal = "Journal of Iberian Geology",
    abstract = "Abstract Dinosaur tracks are considerably common in the fossil record and were described from many areas in the world. They provide a live picture of dinosaur behaviour and offer valuable data about different aspects of the trackmaker paleobiology. The dinosaur ichnological record allows gain information about autopod anatomy, functional adaptations, stance and gaits with which dinosaurs moved. This information, which is often difficult to obtain from the body-fossil record alone, allows making inferences not only concerning the single individuals who produced the footprints, but also within an evolutionary context. Footprints provide also evidences about the abilities that dinosaurs had to swim, run or live with certain pathologies. They also allowed inferring how they move in herds or even made courtship rituals. The study of tracks also enables the reconstruction of paleocommunities including predator–prey interaction. On the other hand, footprints are useful paleoenvironmental indicators, informing about moisture content, bathymetry, paleocurrents, subaqueous substrates, zonations in lacustrine margins, etc. In addition, it has been proposed that dinosaur track assemblages can be related to certain facies (ichnofacies), in order to refine paleoenvironmental reconstructions. Dinosaur tracks can sometimes be in the shadow with respect to the skeletal record. However, the data obtained from the ichnological record complements and completes the knowledge we have about the life of dinosaurs, even showing previously unknown aspects. This work is an overview of the information we can obtain from the study of non-avian dinosaur footprints, trying to answer some questions about their life.",
    url = "https://doi.org/10.1007/s41513-023-00226-6",
    doi = "10.1007/s41513-023-00226-6",
    openalex = "W4390334302",
    references = "doi101002spp21430, doi10100797830311398338, doi1010800891296320181516766, doi101111brv12829, doi101111pala12584, doi107717peerj5358"
}

@article{doi101016jearscirev2023104587,
    author = "Sidor, Christian A. and McIntosh, Julia A. and Gee, Bryan M. and Hammer, William R. and Makovicky, Peter J. and Smith, Nathan D. and Smith, Roger M. H. and Tabor, Neil J. and Whitney, Megan R. and Woolley, C. Henrik",
    title = "The Fremouw Formation of Antarctica: Updated vertebrate fossil record and reevaluation of high-latitude Permian–Triassic paleoenvironments",
    year = "2023",
    journal = "Earth-Science Reviews",
    url = "https://doi.org/10.1016/j.earscirev.2023.104587",
    doi = "10.1016/j.earscirev.2023.104587",
    openalex = "W4387432350",
    references = "doi101016jcub202105041, doi101016jearscirev201206007, doi101017s0032247400063804, doi101038142234b0, doi101080037362451938105591187, doi101126science1224126, doi1011300016760619931050129cop23co2, doi1011301052517320040144caapdo20co2, doi101180mono5, doi101371journalpone0126946, openalexw2482216212"
}

Footprint morphology reflects the anatomy of the trackmaker's foot and is direct evidence for the animal's behaviour. Consequently, fossil tracks can be used to infer ancient diversity, ethology, and evolutionary trends. This is particularly useful for deep-time intervals during which the early history of an animal group is reliant upon limited fossil skeletal material. Fossil tracks of early birds and theropods, the co-existing dinosaurian ancestors of birds, co-occur in the rock record since the Early Cretaceous. However, the evolutionary transition from dinosaur to bird and the timing of the birds' origin are still contested. Skeletal remains of the basal-most birds Aurornis, Anchiornis, Archaeopteryx and Xiaotingia are Middle to Late Jurassic, while tracks with tentative bird affinities, attributed to dinosaurs, are known from as early as the Late Triassic. Here, we present numerous, well-provenanced, Late Triassic and Early Jurassic tridactyl tracks from southern Africa, with demonstrable bird-like affinities, predating basal bird body fossils by c. 60 million years.

@article{doi101371journalpone0293021,
    author = "Abrahams, Miengah and Bordy, Emese M",
    title = "The oldest fossil bird-like footprints from the upper Triassic of southern Africa.",
    year = "2023",
    journal = "PloS one",
    abstract = "Footprint morphology reflects the anatomy of the trackmaker's foot and is direct evidence for the animal's behaviour. Consequently, fossil tracks can be used to infer ancient diversity, ethology, and evolutionary trends. This is particularly useful for deep-time intervals during which the early history of an animal group is reliant upon limited fossil skeletal material. Fossil tracks of early birds and theropods, the co-existing dinosaurian ancestors of birds, co-occur in the rock record since the Early Cretaceous. However, the evolutionary transition from dinosaur to bird and the timing of the birds' origin are still contested. Skeletal remains of the basal-most birds Aurornis, Anchiornis, Archaeopteryx and Xiaotingia are Middle to Late Jurassic, while tracks with tentative bird affinities, attributed to dinosaurs, are known from as early as the Late Triassic. Here, we present numerous, well-provenanced, Late Triassic and Early Jurassic tridactyl tracks from southern Africa, with demonstrable bird-like affinities, predating basal bird body fossils by c. 60 million years.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC10686444/",
    doi = "10.1371/journal.pone.0293021",
    openalex = "W4389133121",
    pmcid = "PMC10686444",
    pmid = "38019739",
    references = "doi1010079789400904095, doi101016jcub201508003, doi101016jearscirev2020103120, doi101038nature08322, doi101038nature12168, doi101038nature13467, doi101038nmeth2089, doi101073pnas2023170118, doi10108002724634199810011086, doi101111pala12373"
}

Mermithid nematodes are obligate invertebrate parasites dating back to the Early Cretaceous. Their fossil record is sparse, especially before the Cenozoic, thus little is known about their early host associations. This study reports 16 new mermithids associated with their insect hosts from mid-Cretaceous Kachin amber, 12 of which include previously unknown hosts. These fossils indicate that mermithid parasitism of invertebrates was already widespread and played an important role in the mid-Cretaceous terrestrial ecosystem. Remarkably, three hosts (bristletails, barklice, and perforissid planthoppers) were previously unknown to be parasitized by mermithids both past and present. Furthermore, our study shows that in contrast to their Cenozoic counterparts, Cretaceous nematodes including mermithids are more abundant in non-holometabolous insects. This result suggests that nematodes had not completely exploited the dominant Holometabola as their hosts until the Cenozoic. This study reveals what appears to be a vanished history of nematodes that parasitized Cretaceous insects.

@article{doi107554elife86283,
    author = "Luo, Cihang and Poinar, George O. and Xu, Chunpeng and Zhuo, De and Jarzembowski, Edmund A. and Wáng, Bó",
    title = "Widespread mermithid nematode parasitism of Cretaceous insects",
    year = "2023",
    journal = "eLife",
    abstract = "Mermithid nematodes are obligate invertebrate parasites dating back to the Early Cretaceous. Their fossil record is sparse, especially before the Cenozoic, thus little is known about their early host associations. This study reports 16 new mermithids associated with their insect hosts from mid-Cretaceous Kachin amber, 12 of which include previously unknown hosts. These fossils indicate that mermithid parasitism of invertebrates was already widespread and played an important role in the mid-Cretaceous terrestrial ecosystem. Remarkably, three hosts (bristletails, barklice, and perforissid planthoppers) were previously unknown to be parasitized by mermithids both past and present. Furthermore, our study shows that in contrast to their Cenozoic counterparts, Cretaceous nematodes including mermithids are more abundant in non-holometabolous insects. This result suggests that nematodes had not completely exploited the dominant Holometabola as their hosts until the Cenozoic. This study reveals what appears to be a vanished history of nematodes that parasitized Cretaceous insects.",
    url = "https://doi.org/10.7554/elife.86283",
    doi = "10.7554/elife.86283",
    openalex = "W4384276777",
    references = "doi101016janbehav202009010"
}

Studying fossils from a mass-mortality event reveals evidence for sexual dimorphism and, unusually, equal numbers of males and females in a herd of dinosaurs.

@article{doi107554elife89158,
    author = "Ludwig, Stella A and Smith, Roy E. and Ibrahim, Nizar",
    title = "Sexual dimorphism in dinosaurs",
    year = "2023",
    journal = "eLife",
    abstract = "Studying fossils from a mass-mortality event reveals evidence for sexual dimorphism and, unusually, equal numbers of males and females in a herd of dinosaurs.",
    url = "https://doi.org/10.7554/elife.89158",
    doi = "10.7554/elife.89158",
    openalex = "W4380577189",
    references = "doi101093biolinneanblaa105"
}

Recent years have seen increasing scientific interest in whether neuron counts can act as correlates of diverse biological phenomena. Lately, Herculano-Houzel (2023) argued that fossil endocasts and comparative neurological data from extant sauropsids allow to reconstruct telencephalic neuron counts in Mesozoic dinosaurs and pterosaurs, which might act as proxies for behaviors and life history traits in these animals. According to this analysis, large theropods such as Tyrannosaurus rex were long-lived, exceptionally intelligent animals equipped with "macaque- or baboon-like cognition", whereas sauropods and most ornithischian dinosaurs would have displayed significantly smaller brains and an ectothermic physiology. Besides challenging established views on Mesozoic dinosaur biology, these claims raise questions on whether neuron count estimates could benefit research on fossil animals in general. Here, we address these findings by revisiting Herculano-Houzel's (2023) work, identifying several crucial shortcomings regarding analysis and interpretation. We present revised estimates of encephalization and telencephalic neuron counts in dinosaurs, which we derive from phylogenetically informed modeling and an amended dataset of endocranial measurements. For large-bodied theropods in particular, we recover significantly lower neuron counts than previously proposed. Furthermore, we review the suitability of neurological variables such as neuron numbers and relative brain size to predict cognitive complexity, metabolic rate and life history traits in dinosaurs, coming to the conclusion that they are flawed proxies for these biological phenomena. Instead of relying on such neurological estimates when reconstructing Mesozoic dinosaur biology, we argue that integrative studies are needed to approach this complex subject.

@article{doi101002ar25459,
    author = "Caspar, Kai R. and Gutiérrez‐Ibáñez, Cristián and Bertrand, Ornella and Carr, Thomas D. and Colbourne, Jennifer and Erb, Arthur and George, Hady and Holtz, Thomas R. and Naish, Darren and Wylie, Douglas R. and Hurlburt, Grant R.",
    title = "How smart was T. rex? Testing claims of exceptional cognition in dinosaurs and the application of neuron count estimates in palaeontological research",
    year = "2024",
    journal = "The Anatomical Record",
    abstract = {Recent years have seen increasing scientific interest in whether neuron counts can act as correlates of diverse biological phenomena. Lately, Herculano-Houzel (2023) argued that fossil endocasts and comparative neurological data from extant sauropsids allow to reconstruct telencephalic neuron counts in Mesozoic dinosaurs and pterosaurs, which might act as proxies for behaviors and life history traits in these animals. According to this analysis, large theropods such as Tyrannosaurus rex were long-lived, exceptionally intelligent animals equipped with "macaque- or baboon-like cognition", whereas sauropods and most ornithischian dinosaurs would have displayed significantly smaller brains and an ectothermic physiology. Besides challenging established views on Mesozoic dinosaur biology, these claims raise questions on whether neuron count estimates could benefit research on fossil animals in general. Here, we address these findings by revisiting Herculano-Houzel's (2023) work, identifying several crucial shortcomings regarding analysis and interpretation. We present revised estimates of encephalization and telencephalic neuron counts in dinosaurs, which we derive from phylogenetically informed modeling and an amended dataset of endocranial measurements. For large-bodied theropods in particular, we recover significantly lower neuron counts than previously proposed. Furthermore, we review the suitability of neurological variables such as neuron numbers and relative brain size to predict cognitive complexity, metabolic rate and life history traits in dinosaurs, coming to the conclusion that they are flawed proxies for these biological phenomena. Instead of relying on such neurological estimates when reconstructing Mesozoic dinosaur biology, we argue that integrative studies are needed to approach this complex subject.},
    url = "https://doi.org/10.1002/ar.25459",
    doi = "10.1002/ar.25459",
    openalex = "W4395665019",
    references = "doi101002cne25458, doi10100797830311398338, doi101016jcub202105041, doi101016s0047248477801358, doi10103844766, doi101038nature11631, doi101038srep18952, doi10108010635150802302427, doi101086303327, doi101093bioinformaticsbty633, doi101093molbevmsx116, doi101126science1157704, doi101126science2985593556, doi101126scienceabl5584, doi1012063521, doi101371journalpone0298242"
}

Among extant species, the ability to sample the extremes of body size-one of the most useful predictors of an individual's ecology-is highly unlikely. This improbability is further exaggerated when sampling the already incomplete fossil record. We quantify the likelihood of sampling the uppermost limits of body size in the fossil record using Tyrannosaurus rex Osborn, 1905 as a model, selected for its comparatively well-understood life history parameters. We computationally generate a population of 140 million T. rex (based on prior estimates), modelling variation about the growth curve both with and without sexual dimorphism (the former modelled after Alligator mississippiensis), and building in sampling limitations related to species survivorship and taphonomic bias, derived from fossil data. The 99th percentile of body mass in T. rex has likely already been sampled, but it will probably be millennia before much larger giants (99.99th percentile) are sampled at present collecting rates. Biomechanical and ecological limitations notwithstanding, we estimate that the absolute largest T. rex may have been 70% more massive than the currently largest known specimen (~15,000 vs. ~8800 kg). Body size comparisons of fossil species should be based on ontogenetically controlled statistical parameters, rather than simply comparing the largest known individuals whose recovery is highly subject to sampling intensity.

@article{doi101002ece311658,
    author = "Mallon, Jordan C. and Hone, David W. E.",
    title = "Estimation of maximum body size in fossil species: A case study using Tyrannosaurus rex",
    year = "2024",
    journal = "Ecology and Evolution",
    abstract = "Among extant species, the ability to sample the extremes of body size-one of the most useful predictors of an individual's ecology-is highly unlikely. This improbability is further exaggerated when sampling the already incomplete fossil record. We quantify the likelihood of sampling the uppermost limits of body size in the fossil record using Tyrannosaurus rex Osborn, 1905 as a model, selected for its comparatively well-understood life history parameters. We computationally generate a population of 140 million T. rex (based on prior estimates), modelling variation about the growth curve both with and without sexual dimorphism (the former modelled after Alligator mississippiensis), and building in sampling limitations related to species survivorship and taphonomic bias, derived from fossil data. The 99th percentile of body mass in T. rex has likely already been sampled, but it will probably be millennia before much larger giants (99.99th percentile) are sampled at present collecting rates. Biomechanical and ecological limitations notwithstanding, we estimate that the absolute largest T. rex may have been 70\% more massive than the currently largest known specimen (\textasciitilde 15,000 vs. \textasciitilde 8800 kg). Body size comparisons of fossil species should be based on ontogenetically controlled statistical parameters, rather than simply comparing the largest known individuals whose recovery is highly subject to sampling intensity.",
    url = "https://doi.org/10.1002/ece3.11658",
    doi = "10.1002/ece3.11658",
    openalex = "W4400955568",
    references = "doi101093biolinneanblaa105, doi101139cjes20200169, doi103390fossils2010001"
}

Abstract The Late Miocene natural traps of Cerro de los Batallones (Madrid, Spain) have yielded thousands of fossils of vertebrates, mostly carnivoran mammals such as hyaenids, amphicyonids, ailurids, mustelids, ursids, and felids, especially Batallones-1 and Batallones-3. Among these carnivorans, the tiger-sized saber-toothed felid Machairodus aphanistus was the top predator of the association, and one of the most abundant taxa, represented by thousands of fossils, including several examples of bone pathologies that have never been studied. In this work, we carry out a paleopathological analysis of some of these pathologies from the Batallones sample of this large early machairodontine, with a description of the pathological changes that occurred in the affected bones, a possible diagnosis, and the ethological and ecological consequences of the presence of these diseases in the living animal. The pathological sample of M. aphanistus studied here included a calcaneus and a Mc III from Batallones-1, and a mandible from Batallones-3. The fossils were X-rayed, and their pathologies were described and compared to non-pathological bones. The calcaneus showed a bone callus indicative of osteitis/osteomyelitis or a tumor; the mandible had evidence of the development of an abscess located in the left mandibular body; and the Mc III shows a marked osteosclerosis. These injuries affected the hunting ability of these individuals and gradually weakened them, very likely contributing to their final entrapment in the Batallones cavities, where they were attracted by the presence of previously trapped animals.

@article{doi101007s10914024097218,
    author = "Salesa, Manuel J. and Hernández, Bárbara and Marín, Pilar and Siliceo, Gema and Martínez, Irene María Briones and Antón, Mauricio and Real, Isabel García and Pastor, Juan Francisco and García‐Fernández, Rosa A.",
    title = "New insights on the ecology and behavior of Machairodus aphanistus (Carnivora, Felidae, Machairodontinae) through the paleopathological study of the fossil sample from the Late Miocene (Vallesian, MN 10) of Cerro de los Batallones (Torrejón de Velasco, Madrid, Spain)",
    year = "2024",
    journal = "Journal of Mammalian Evolution",
    abstract = "Abstract The Late Miocene natural traps of Cerro de los Batallones (Madrid, Spain) have yielded thousands of fossils of vertebrates, mostly carnivoran mammals such as hyaenids, amphicyonids, ailurids, mustelids, ursids, and felids, especially Batallones-1 and Batallones-3. Among these carnivorans, the tiger-sized saber-toothed felid Machairodus aphanistus was the top predator of the association, and one of the most abundant taxa, represented by thousands of fossils, including several examples of bone pathologies that have never been studied. In this work, we carry out a paleopathological analysis of some of these pathologies from the Batallones sample of this large early machairodontine, with a description of the pathological changes that occurred in the affected bones, a possible diagnosis, and the ethological and ecological consequences of the presence of these diseases in the living animal. The pathological sample of M. aphanistus studied here included a calcaneus and a Mc III from Batallones-1, and a mandible from Batallones-3. The fossils were X-rayed, and their pathologies were described and compared to non-pathological bones. The calcaneus showed a bone callus indicative of osteitis/osteomyelitis or a tumor; the mandible had evidence of the development of an abscess located in the left mandibular body; and the Mc III shows a marked osteosclerosis. These injuries affected the hunting ability of these individuals and gradually weakened them, very likely contributing to their final entrapment in the Batallones cavities, where they were attracted by the presence of previously trapped animals.",
    url = "https://doi.org/10.1007/s10914-024-09721-8",
    doi = "10.1007/s10914-024-09721-8",
    openalex = "W4399234761",
    references = "doi101038s41598022057613"
}

@article{doi101016jpalaeo2024112487,
    author = "Melchor, Ricardo N. and Perez, Mariano and Umazano, Aldo M.",
    title = "Are aeolian ichnofacies distinctive and useful? An analysis of trace fossil assemblages from Cretaceous aeolian facies in northern Patagonia, Argentina",
    year = "2024",
    journal = "Palaeogeography Palaeoclimatology Palaeoecology",
    url = "https://doi.org/10.1016/j.palaeo.2024.112487",
    doi = "10.1016/j.palaeo.2024.112487",
    openalex = "W4402313509",
    references = "doi101016jearscirev2023104587"
}

Global climate patterns fundamentally shape the distribution of species and ecosystems. For example, Bergmann's rule predicts that homeothermic animals, including birds and mammals, inhabiting cooler climates are generally larger than close relatives from warmer climates. The modern world, however, lacks the comparative data needed to evaluate such macroecological rules rigorously. Here, we test for Bergmann's rule in Mesozoic dinosaurs and mammaliaforms that radiated within relatively temperate global climate regimes. We develop a phylogenetic model that accounts for biases in the fossil record and allows for variable evolutionary dispersal rates. Our analysis also includes new fossil data from the extreme high-latitude Late Cretaceous Arctic Prince Creek Formation. We find no evidence for Bergmann's rule in Mesozoic dinosaurs or mammaliaforms, the ancestors of extant homeothermic birds and mammals. When our model is applied to thousands of extant dinosaur (bird) and mammal species, we find that body size evolution remains independent of latitude. A modest temperature effect is found in extant, but not in Mesozoic, birds, suggesting that body size evolution in modern birds was influenced by Bergmann's rule during Cenozoic climatic change. Our study provides a general approach for studying macroecological rules, highlighting the fossil record's power to address longstanding ecological principles.

@article{doi101038s41467024468432,
    author = "Wilson, Lauren N. and Gardner, Jacob D. and Wilson, John P. and Farnsworth, Alex and Perry, Zackary R. and Druckenmiller, Patrick S. and Erickson, Gregory M. and Organ, Chris L.",
    title = "Global latitudinal gradients and the evolution of body size in dinosaurs and mammals",
    year = "2024",
    journal = "Nature Communications",
    abstract = "Global climate patterns fundamentally shape the distribution of species and ecosystems. For example, Bergmann's rule predicts that homeothermic animals, including birds and mammals, inhabiting cooler climates are generally larger than close relatives from warmer climates. The modern world, however, lacks the comparative data needed to evaluate such macroecological rules rigorously. Here, we test for Bergmann's rule in Mesozoic dinosaurs and mammaliaforms that radiated within relatively temperate global climate regimes. We develop a phylogenetic model that accounts for biases in the fossil record and allows for variable evolutionary dispersal rates. Our analysis also includes new fossil data from the extreme high-latitude Late Cretaceous Arctic Prince Creek Formation. We find no evidence for Bergmann's rule in Mesozoic dinosaurs or mammaliaforms, the ancestors of extant homeothermic birds and mammals. When our model is applied to thousands of extant dinosaur (bird) and mammal species, we find that body size evolution remains independent of latitude. A modest temperature effect is found in extant, but not in Mesozoic, birds, suggesting that body size evolution in modern birds was influenced by Bergmann's rule during Cenozoic climatic change. Our study provides a general approach for studying macroecological rules, highlighting the fossil record's power to address longstanding ecological principles.",
    url = "https://doi.org/10.1038/s41467-024-46843-2",
    doi = "10.1038/s41467-024-46843-2",
    openalex = "W4394006486",
    references = "doi1010079781441903181, doi101007s003820050276, doi101016jcub202105041, doi101016jtree201103005, doi101038nature05634, doi101046j14724642199900046x, doi101093bioinformaticsbtg412, doi101093molbevmsac174, doi101093sysbiosyq085, doi101126science1116030, doi101159000452856"
}

One of the five greatest mass extinction events in the history of life occurred at the end of the Triassic (~ 201 million years ago), as confirmed by profound loss of life in marine realm. Terrestrial ecosystems were also suffered but the extent of life loss and timing of subsequent recovery remain equivocal, largely because of scarcity of fossil record. Here we report an exceptionally-preserved fossil assemblage, Yuzhou Biota, from the Sinemurian (~ 199-193 Ma), Early Jurassic lacustrine deposits of northern Chongqing, China. The biota documents the first known trophically complex lacustrine ecosystem after the end-Triassic extinction in China, including various representative species ranging from primary consumers (e.g., ostracods, conchostracans, gastropods and bivalves) to large predators (e.g., a variety of jawed fishes and pliosauroids). The most striking feature is its diversified aquatic vertebrates; the hybodontiforms, ceratodontiforms, ptycholepiformes, ginglymodians and pliosauroids from the biota all represent their first occurrences above the Triassic-Jurassic boundary in China. As such, the discovery enriches our understanding of the faunal turnover of aquatic vertebrates following the end-Triassic mass extinction, and provides a novel window on the Early Jurassic lacustrine ecosystems.

@article{doi101038s41598024770844,
    author = "Ren, Tingyun and Ma, Xin-Ying and Wang, Qing‐Dong and Xu, Guanghui",
    title = "An exceptionally preserved fossil assemblage from the early Jurassic of Chongqing (China) reveals a complex lacustrine ecosystem",
    year = "2024",
    journal = "Scientific Reports",
    abstract = "One of the five greatest mass extinction events in the history of life occurred at the end of the Triassic (\textasciitilde\ 201 million years ago), as confirmed by profound loss of life in marine realm. Terrestrial ecosystems were also suffered but the extent of life loss and timing of subsequent recovery remain equivocal, largely because of scarcity of fossil record. Here we report an exceptionally-preserved fossil assemblage, Yuzhou Biota, from the Sinemurian (\textasciitilde\ 199-193 Ma), Early Jurassic lacustrine deposits of northern Chongqing, China. The biota documents the first known trophically complex lacustrine ecosystem after the end-Triassic extinction in China, including various representative species ranging from primary consumers (e.g., ostracods, conchostracans, gastropods and bivalves) to large predators (e.g., a variety of jawed fishes and pliosauroids). The most striking feature is its diversified aquatic vertebrates; the hybodontiforms, ceratodontiforms, ptycholepiformes, ginglymodians and pliosauroids from the biota all represent their first occurrences above the Triassic-Jurassic boundary in China. As such, the discovery enriches our understanding of the faunal turnover of aquatic vertebrates following the end-Triassic mass extinction, and provides a novel window on the Early Jurassic lacustrine ecosystems.",
    url = "https://doi.org/10.1038/s41598-024-77084-4",
    doi = "10.1038/s41598-024-77084-4",
    openalex = "W4404587337",
    references = "doi101144sp5382022323"
}

Dinosaurs thrived for over 160 million years in Mesozoic ecosystems, displaying diverse ecological and evolutionary adaptations. Their ecology was shaped by large-scale climatic and biogeographic changes, calling for a 'deep-time' macroecological investigation. These factors include temperature fluctuations and the break up of Pangaea, influencing species richness, ecological diversity and biogeographic history. Recent improvements in the dinosaur fossil record have enabled large-scale studies of their responses to tectonic, geographic and climatic shifts. Trends in species diversity, body size and reproductive traits can now be analysed using quantitative approaches like phylogenetic comparative methods, machine learning and Bayesian inference. These patterns sometimes align with, but also deviate from, first-order macroecological rules (e.g. species-area relationship, latitudinal biodiversity gradient, Bergmann's rule). Accurate reconstructions of palaeobiodiversity and niche partitioning require ongoing taxonomic revisions and detailed anatomical descriptions. Interdisciplinary research combining sedimentology, geochemistry and palaeoclimatology helps uncover the environmental conditions driving dinosaur adaptations. Fieldwork in under-sampled regions, particularly at latitudinal extremes, is crucial for understanding the spatial heterogeneity of dinosaur ecosystems across the planet. Open science initiatives and online databases play a key role in advancing this field, enriching our understanding of deep-time ecological processes, and offering new insights into dinosaur macroecology and its broader implications.

@article{doi101098rsbl20240392,
    author = "Chiarenza, Alfio Alessandro",
    title = "The macroecology of Mesozoic dinosaurs",
    year = "2024",
    journal = "Biology Letters",
    abstract = "Dinosaurs thrived for over 160 million years in Mesozoic ecosystems, displaying diverse ecological and evolutionary adaptations. Their ecology was shaped by large-scale climatic and biogeographic changes, calling for a 'deep-time' macroecological investigation. These factors include temperature fluctuations and the break up of Pangaea, influencing species richness, ecological diversity and biogeographic history. Recent improvements in the dinosaur fossil record have enabled large-scale studies of their responses to tectonic, geographic and climatic shifts. Trends in species diversity, body size and reproductive traits can now be analysed using quantitative approaches like phylogenetic comparative methods, machine learning and Bayesian inference. These patterns sometimes align with, but also deviate from, first-order macroecological rules (e.g. species-area relationship, latitudinal biodiversity gradient, Bergmann's rule). Accurate reconstructions of palaeobiodiversity and niche partitioning require ongoing taxonomic revisions and detailed anatomical descriptions. Interdisciplinary research combining sedimentology, geochemistry and palaeoclimatology helps uncover the environmental conditions driving dinosaur adaptations. Fieldwork in under-sampled regions, particularly at latitudinal extremes, is crucial for understanding the spatial heterogeneity of dinosaur ecosystems across the planet. Open science initiatives and online databases play a key role in advancing this field, enriching our understanding of deep-time ecological processes, and offering new insights into dinosaur macroecology and its broader implications.",
    url = "https://doi.org/10.1098/rsbl.2024.0392",
    doi = "10.1098/rsbl.2024.0392",
    openalex = "W4404328467",
    references = "chiarenza2024early, doi101002spp21487, doi101016jearscirev2023104537, doi101038s41467024468432, doi1010801477201920242346577, doi101111pala12591, doi101139cjes20200145, doi101371journalpone0235078, doi102110palo2016041, doi104202app001522015"
}

Dinosaurs potentially originated in the mid-palaeolatitudes of Gondwana 245-235 million years ago (Ma) and may have been restricted to cooler, humid areas by low-latitude arid zones until climatic amelioration made northern dispersals feasible ca 215 Ma. However, this scenario is challenged by new Carnian Laurasian fossils and evidence that even the earliest dinosaurs had adaptations for arid conditions. After becoming globally distributed in the Early-Middle Jurassic (200-160 Ma), dinosaurs experienced vicariance driven by Pangaean fragmentation. Regional extinctions and trans-oceanic dispersals also played a role, and the formation of ephemeral land connections meant that older vicariance patterns were repeatedly overprinted by younger ones, creating a reticulate biogeographic history. Palaeoclimates shaped dispersal barriers and corridors, including filters that had differential effects on different types of dinosaurs. Dinosaurian biogeographic research faces many challenges, not the least of which is the patchiness of the fossil record. However, new fossils, extensive databasing and improved analytical methods help distinguish signal from noise and generate fresh perspectives. In the future, developing techniques for quantifying and ameliorating sampling biases and modelling the dispersal capacities of dinosaurs are likely to be two of the key components in our modern research programme.

@article{doi101098rsbl20240429,
    author = "Upchurch, Paul and Chiarenza, Alfio Alessandro",
    title = "A brief review of non-avian dinosaur biogeography: state-of-the-art and prospectus",
    year = "2024",
    journal = "Biology Letters",
    abstract = "Dinosaurs potentially originated in the mid-palaeolatitudes of Gondwana 245-235 million years ago (Ma) and may have been restricted to cooler, humid areas by low-latitude arid zones until climatic amelioration made northern dispersals feasible ca 215 Ma. However, this scenario is challenged by new Carnian Laurasian fossils and evidence that even the earliest dinosaurs had adaptations for arid conditions. After becoming globally distributed in the Early-Middle Jurassic (200-160 Ma), dinosaurs experienced vicariance driven by Pangaean fragmentation. Regional extinctions and trans-oceanic dispersals also played a role, and the formation of ephemeral land connections meant that older vicariance patterns were repeatedly overprinted by younger ones, creating a reticulate biogeographic history. Palaeoclimates shaped dispersal barriers and corridors, including filters that had differential effects on different types of dinosaurs. Dinosaurian biogeographic research faces many challenges, not the least of which is the patchiness of the fossil record. However, new fossils, extensive databasing and improved analytical methods help distinguish signal from noise and generate fresh perspectives. In the future, developing techniques for quantifying and ameliorating sampling biases and modelling the dispersal capacities of dinosaurs are likely to be two of the key components in our modern research programme.",
    url = "https://doi.org/10.1098/rsbl.2024.0429",
    doi = "10.1098/rsbl.2024.0429",
    openalex = "W4403856200",
    references = "chiarenza2024early, crossref1998encyclopedia, doi101016jcretres201603008, doi101016jcub202105041, doi101016jcub202111061, doi101016jearscirev201203002, doi101016jearscirev2023104537, doi101016jjsames2021103341, doi101016jpalaeo201602033, doi101017s1755691013000431, doi101038s41467018051281, doi101038s41559021016515, doi101038s4158602205133x, doi101038s41598020576677, doi101038s41598021837455, doi101073pnas2020778118, doi101080027246342010520779, doi1010800272463420232199810, doi1010800891296320201793979, doi1010800891296320242336992, doi10108010635150701883881, doi1010801477201920242345333, doi101086648217, doi101093sysbiosyu056, doi101098rsbl20180431, doi101111pala12496, doi101111pala12514, doi101126science1161833, doi101146annurevearth081320064052, doi101371journalpone0012553, doi101371journalpone0112055, doi101371journalpone0235078, doi1021425f55419694, doi1023072413039, doi1023073243019, doi1029920070860302, doi105860choice353642"
}

Much of our view on Mesozoic dinosaur diversity is obscured by biases in the fossil record. In particular, spatiotemporal sampling heterogeneity affects identification of the timing and geographical location of radiations, the recognition of the latitudinal diversity gradient, as well as interpretation of purported extinctions, faunal turnovers and their drivers, including the Early Jurassic Jenkyns Event and across the Jurassic/Cretaceous boundary. The current distribution of sampling means it is impossible to robustly determine whether these 'events' were globally synchronous and geologically instantaneous or spatiotemporally staggered. Accounting for sampling heterogeneity is also paramount to reconciling notable differences in results based on sampling-standardized dinosaur species richness versus reconstructions of diversification rates, particularly with regards to the lead-up to the Cretaceous/Paleogene mass extinction. Incorporation of a greater proportion of stratigraphically well-resolved dinosaurs into analyses is also imperative and must include the substantial Mesozoic radiation of birds. Given the relative rarity of temporally successive, well-sampled spatial windows, it remains possible that dinosaur species richness and diversification rate showed little change after the clade's initial radiation until the Cretaceous/Paleogene boundary. However, better understanding of underlying sampling, combined with a holistic approach to reconstructing dinosaur diversity and diversification, is an important step in testing this hypothesis.

@article{doi101098rsbl20240443,
    author = "Mannion, Philip D.",
    title = "The spatiotemporal distribution of Mesozoic dinosaur diversity",
    year = "2024",
    journal = "Biology Letters",
    abstract = "Much of our view on Mesozoic dinosaur diversity is obscured by biases in the fossil record. In particular, spatiotemporal sampling heterogeneity affects identification of the timing and geographical location of radiations, the recognition of the latitudinal diversity gradient, as well as interpretation of purported extinctions, faunal turnovers and their drivers, including the Early Jurassic Jenkyns Event and across the Jurassic/Cretaceous boundary. The current distribution of sampling means it is impossible to robustly determine whether these 'events' were globally synchronous and geologically instantaneous or spatiotemporally staggered. Accounting for sampling heterogeneity is also paramount to reconciling notable differences in results based on sampling-standardized dinosaur species richness versus reconstructions of diversification rates, particularly with regards to the lead-up to the Cretaceous/Paleogene mass extinction. Incorporation of a greater proportion of stratigraphically well-resolved dinosaurs into analyses is also imperative and must include the substantial Mesozoic radiation of birds. Given the relative rarity of temporally successive, well-sampled spatial windows, it remains possible that dinosaur species richness and diversification rate showed little change after the clade's initial radiation until the Cretaceous/Paleogene boundary. However, better understanding of underlying sampling, combined with a holistic approach to reconstructing dinosaur diversity and diversification, is an important step in testing this hypothesis.",
    url = "https://doi.org/10.1098/rsbl.2024.0443",
    doi = "10.1098/rsbl.2024.0443",
    openalex = "W4405257820",
    references = "doi101016jcub202105041, doi101016jearscirev201004001, doi101016jearscirev2023104537, doi101016jearscirev2023104630, doi101038nature03150, doi101038nature11631, doi1010801477201920242346577, doi101098rspb20080715, doi101111j1469185x200900094x, doi101111pala12496, doi101126science1189910, doi101126science17740541065, doi101126science28454232137, doi101371journalpone0297637, doi1018901119521, sereno1997the"
}

Our fascination with dinosaur brains and their capabilities essentially began with the first dinosaur discovery. The history of this study is a useful reflection of palaeoneurology as a whole and its relationship to a more inclusive evolutionary neuroscience. I argue that this relationship is imbued with high heuristic potential, but one whose realization requires overcoming certain constraints. These constraints include the need for a stable phylogenetic framework, methods for efficient and precise endocast construction, and fossil researchers who are steeped in a neuroscience perspective. The progress that has already been made in these areas sets the stage for a more mature palaeoneurology-not only one capable of being informed by neuroscience discoveries but one that drives such discoveries. I draw from work on the size, shape, behavioural correlates and developmental role of the dinosaur brain to outline current advances in dinosaur palaeoneurology. My examples largely are taken from theropods and centre on questions related to the origin of birds and their unique locomotory capabilities. The hope, however, is that these exemplify the potential for study in other dinosaur groups, and for utilizing the dinosaur-bird lineage as a parallel model on a par with mammals for studying encephalization.

@article{doi101098rsbl20240472,
    author = "Balanoff, Amy M.",
    title = "Dinosaur palaeoneurology: an evolving science",
    year = "2024",
    journal = "Biology Letters",
    abstract = "Our fascination with dinosaur brains and their capabilities essentially began with the first dinosaur discovery. The history of this study is a useful reflection of palaeoneurology as a whole and its relationship to a more inclusive evolutionary neuroscience. I argue that this relationship is imbued with high heuristic potential, but one whose realization requires overcoming certain constraints. These constraints include the need for a stable phylogenetic framework, methods for efficient and precise endocast construction, and fossil researchers who are steeped in a neuroscience perspective. The progress that has already been made in these areas sets the stage for a more mature palaeoneurology-not only one capable of being informed by neuroscience discoveries but one that drives such discoveries. I draw from work on the size, shape, behavioural correlates and developmental role of the dinosaur brain to outline current advances in dinosaur palaeoneurology. My examples largely are taken from theropods and centre on questions related to the origin of birds and their unique locomotory capabilities. The hope, however, is that these exemplify the potential for study in other dinosaur groups, and for utilizing the dinosaur-bird lineage as a parallel model on a par with mammals for studying encephalization.",
    url = "https://doi.org/10.1098/rsbl.2024.0472",
    doi = "10.1098/rsbl.2024.0472",
    openalex = "W4405485330",
    references = "doi101002ar25459, doi101002cne25458, doi10103844766, doi101038nrg2829, doi101038nrn1606, doi101073pnas1319091111, doi10108010635150490522232, doi101086426002, doi101098rstb19890106, doi101126science1253451, doi102475ajss319111253, doi105860choice425260, lauters2023endocasts"
}

True substrates are bedding surfaces that represent the original environmental surfaces that existed at the time of burial. In the clastic depositional regime, there are abiotic and biotic causes that may contribute to the formation of such true substrates. This paper focuses on how sediment-stabilizing microbial mats may increase the preservation potential of true substrates. Baffling and trapping enrich fine-grained particles and heavy minerals in mat textures inducing a layer of heterogeneity in the otherwise homogenous deposits. Together with in situ mineral precipitation during the life time of the microbial mat and post-depositional diagenesis, baffling and trapping contributes to processes leading to bedding plane preservation. Microbial mats interact with the hydrological system of a coastal environment causing typical microbially induced sedimentary structures (MISS). The morphologies of MISS can indicate climate seasonality and zone of the respective true substrate. The interaction of animals and plants with microbial mats allow reconstructing events that took place during the exposure of the original environmental surface. Finally, true substrates displaying MISS are well-defined indicators for life exploration of Earth's oldest sedimentary rock successions and equivalent lithologies on other planets.

@article{doi101144sp556202479,
    author = "Noffke, Nora and Buntin, Caldwell",
    title = "Microbial mats writing the fossil record of true substrates in clastic rock successions",
    year = "2024",
    journal = "Geological Society London Special Publications",
    abstract = "True substrates are bedding surfaces that represent the original environmental surfaces that existed at the time of burial. In the clastic depositional regime, there are abiotic and biotic causes that may contribute to the formation of such true substrates. This paper focuses on how sediment-stabilizing microbial mats may increase the preservation potential of true substrates. Baffling and trapping enrich fine-grained particles and heavy minerals in mat textures inducing a layer of heterogeneity in the otherwise homogenous deposits. Together with in situ mineral precipitation during the life time of the microbial mat and post-depositional diagenesis, baffling and trapping contributes to processes leading to bedding plane preservation. Microbial mats interact with the hydrological system of a coastal environment causing typical microbially induced sedimentary structures (MISS). The morphologies of MISS can indicate climate seasonality and zone of the respective true substrate. The interaction of animals and plants with microbial mats allow reconstructing events that took place during the exposure of the original environmental surface. Finally, true substrates displaying MISS are well-defined indicators for life exploration of Earth's oldest sedimentary rock successions and equivalent lithologies on other planets.",
    url = "https://doi.org/10.1144/sp556-2024-79",
    doi = "10.1144/sp556-2024-79",
    openalex = "W4404374952",
    references = "doi102110jsr201957"
}

Within biology, there exist several rules that seek to describe global trends across species, time scales and space. One such rule, known as Bergmann's rule, says that similar species of warm-blooded animals such as birds and mammals will typically be larger in colder climates as compared with relatives in warmer climates. Bergmann's rule is often interpreted as being tied not only to temperature but also to latitude. Animals in more extreme latitudes are thought to be heavier than those closer to the equator. Scientists have previously thought that the reason for this was that a larger body size helps to regulate internal body temperature more efficiently. This rule has led to much discussion over the years, but recently a team of scientists from the USA, the UK and China, led by Lauren Wilson from the University of Alaska Museum, USA, sought to settle the debate.The scientists began by pulling together information encompassing 62 ancient mammals, ancestors of many creatures alive today, and 339 dinosaurs from fossils approximately 250–66 million years old. To understand how evolution might have played out differently, given all of the random factors that might suddenly send it off in subtly different alternative directions during the multi-million-year process, the researchers created a computer program that let them play through different evolutionary outcomes. From this, they found that a dinosaur's body size is not related to where it is on the Earth or the temperature at that point. This finding was supported by a similar distribution of similarly sized dinosaurs in records from 201, 145 and 66 million years ago. Put a different way, a dinosaur is just as likely to be the same size as closely related species regardless of the temperature, even if they live in places where the coldest month's temperature is different.To get a better picture of evolution over large time scales, the researchers also analysed the body mass and size of 5496 bird and 2305 mammal species that are currently alive today. Birds and mammals make up the two descendants of the dinosaurs from 250–66 million years ago and ancient mammals that the researchers initially pulled together body sizes on. Rerunning their calculations to obtain body mass and size of modern animals in different locations, temperatures and evolutionary scenarios, the researchers found again that an animal's size does not depend on where it is on the planet and how cold it is there. In addition, they found that for a 1°C decrease in temperature, birds increased their body mass 0.8%, which is a small amount of change for most animals. This is particularly interesting as ancient birds from 260–66 million years ago had body masses that were not based on latitude or temperature. This suggests that modern birds’ ancestors in the following geological era – the Cenozoic, 66 million years ago – did vary their body mass depending on the latitude and temperature of their habitat, unlike the earlier dinosaurs.Overall, this study brings into question the commonly held rule in biology that similar species of warm-blooded animals are typically larger in cold climates when compared with relatives in warmer climates, helping to settle a debate about the importance of temperature and location that's been going on for decades. The use of the fossil record also serves as a reminder that even though dinosaurs were alive millions of years ago, they still have a lot to teach us about life today.

@article{doi101242jeb246607,
    author = "Cerbone, Henry",
    title = "Dinosaurs break the rules anywhere not anytime",
    year = "2024",
    journal = "Journal of Experimental Biology",
    abstract = "Within biology, there exist several rules that seek to describe global trends across species, time scales and space. One such rule, known as Bergmann's rule, says that similar species of warm-blooded animals such as birds and mammals will typically be larger in colder climates as compared with relatives in warmer climates. Bergmann's rule is often interpreted as being tied not only to temperature but also to latitude. Animals in more extreme latitudes are thought to be heavier than those closer to the equator. Scientists have previously thought that the reason for this was that a larger body size helps to regulate internal body temperature more efficiently. This rule has led to much discussion over the years, but recently a team of scientists from the USA, the UK and China, led by Lauren Wilson from the University of Alaska Museum, USA, sought to settle the debate.The scientists began by pulling together information encompassing 62 ancient mammals, ancestors of many creatures alive today, and 339 dinosaurs from fossils approximately 250–66 million years old. To understand how evolution might have played out differently, given all of the random factors that might suddenly send it off in subtly different alternative directions during the multi-million-year process, the researchers created a computer program that let them play through different evolutionary outcomes. From this, they found that a dinosaur's body size is not related to where it is on the Earth or the temperature at that point. This finding was supported by a similar distribution of similarly sized dinosaurs in records from 201, 145 and 66 million years ago. Put a different way, a dinosaur is just as likely to be the same size as closely related species regardless of the temperature, even if they live in places where the coldest month's temperature is different.To get a better picture of evolution over large time scales, the researchers also analysed the body mass and size of 5496 bird and 2305 mammal species that are currently alive today. Birds and mammals make up the two descendants of the dinosaurs from 250–66 million years ago and ancient mammals that the researchers initially pulled together body sizes on. Rerunning their calculations to obtain body mass and size of modern animals in different locations, temperatures and evolutionary scenarios, the researchers found again that an animal's size does not depend on where it is on the planet and how cold it is there. In addition, they found that for a 1°C decrease in temperature, birds increased their body mass 0.8\%, which is a small amount of change for most animals. This is particularly interesting as ancient birds from 260–66 million years ago had body masses that were not based on latitude or temperature. This suggests that modern birds’ ancestors in the following geological era – the Cenozoic, 66 million years ago – did vary their body mass depending on the latitude and temperature of their habitat, unlike the earlier dinosaurs.Overall, this study brings into question the commonly held rule in biology that similar species of warm-blooded animals are typically larger in cold climates when compared with relatives in warmer climates, helping to settle a debate about the importance of temperature and location that's been going on for decades. The use of the fossil record also serves as a reminder that even though dinosaurs were alive millions of years ago, they still have a lot to teach us about life today.",
    url = "https://doi.org/10.1242/jeb.246607",
    doi = "10.1242/jeb.246607",
    openalex = "W4400364825",
    references = "doi101038s41467024468432"
}

Dinosaurs thrived for over 160 million years in Mesozoic ecosystems, displaying diverse ecological and evolutionary adaptations. Their ecology was shaped by large-scale climatic and biogeographic changes, calling for a ‘deep-time’ macroecological investigation. These factors include temperature fluctuations and the break up of Pangaea, influencing species richness, ecological diversity and biogeographic history. Recent improvements in the dinosaur fossil record have enabled large-scale studies of their responses to tectonic, geographic and climatic shifts. Trends in species diversity, body size and reproductive traits can now be analysed using quantitative approaches like phylogenetic comparative methods, machine learning and Bayesian inference. These patterns sometimes align with, but also deviate from, first-order macroecological rules (e.g. species–area relationship, latitudinal biodiversity gradient, Bergmann’s rule). Accurate reconstructions of palaeobiodiversity and niche partitioning require ongoing taxonomic revisions and detailed anatomical descriptions. Interdisciplinary research combining sedimentology, geochemistry and palaeoclimatology helps uncover the environmental conditions driving dinosaur adaptations. Fieldwork in under-sampled regions, particularly at latitudinal extremes, is crucial for understanding the spatial heterogeneity of dinosaur ecosystems across the planet. Open science initiatives and online databases play a key role in advancing this field, enriching our understanding of deep-time ecological processes, and offering new insights into dinosaur macroecology and its broader implications.

@misc{doi1052843cassynic02jkh,
    title = "The macroecology of Mesozoic dinosaurs",
    year = "2024",
    abstract = "Dinosaurs thrived for over 160 million years in Mesozoic ecosystems, displaying diverse ecological and evolutionary adaptations. Their ecology was shaped by large-scale climatic and biogeographic changes, calling for a ‘deep-time’ macroecological investigation. These factors include temperature fluctuations and the break up of Pangaea, influencing species richness, ecological diversity and biogeographic history. Recent improvements in the dinosaur fossil record have enabled large-scale studies of their responses to tectonic, geographic and climatic shifts. Trends in species diversity, body size and reproductive traits can now be analysed using quantitative approaches like phylogenetic comparative methods, machine learning and Bayesian inference. These patterns sometimes align with, but also deviate from, first-order macroecological rules (e.g. species–area relationship, latitudinal biodiversity gradient, Bergmann’s rule). Accurate reconstructions of palaeobiodiversity and niche partitioning require ongoing taxonomic revisions and detailed anatomical descriptions. Interdisciplinary research combining sedimentology, geochemistry and palaeoclimatology helps uncover the environmental conditions driving dinosaur adaptations. Fieldwork in under-sampled regions, particularly at latitudinal extremes, is crucial for understanding the spatial heterogeneity of dinosaur ecosystems across the planet. Open science initiatives and online databases play a key role in advancing this field, enriching our understanding of deep-time ecological processes, and offering new insights into dinosaur macroecology and its broader implications.",
    url = "https://doi.org/10.52843/cassyni.c02jkh",
    doi = "10.52843/cassyni.c02jkh",
    openalex = "W4404780710",
    references = "chiarenza2024early, doi101098rsbl20240429"
}

Last year, we challenged the view that large-bodied theropod dinosaurs such as Tyrannosaurus rex resembled primates in cognition and behavior, a proposition made by Herculano-Houzel in 2023. More recently, Jensen et al. have criticized our work on this topic, raising methodological and conceptual issues. Central to their argument is the assumption that tachymetabolic endotherms should be expected to converge in neurocognitive traits, which follows the recently proposed endothermic brain hypothesis. We here respond to their critique, address critical misconceptions, and argue that none of the points raised by Jensen et al. challenge the conclusions we have drawn. We show that the endothermic brain hypothesis lacks robust support from the fossil record. As of now, no compelling evidence suggests that endothermy coevolved with enlarged brains or elevated neuron densities in either the avian or mammalian lineage. Various fossil groups containing endothermic taxa retain plesiomorphic endocast traits and do not converge with birds and mammals in the relative size and proportions of their brains. Furthermore, we elaborate on our discussion on (forebrain) neuron counts as correlates of cognitive performance and highlight that neuron numbers evolve in tandem with body mass in birds and mammals, suggesting that comparatively high neuron number estimates for some Mesozoic dinosaurs do not require explanations that orbit around exceptional cognitive abilities. Despite these disagreements, we identify significant overlap in opinion between Jensen et al. and ourselves, including in the position that neuron count estimates for Mesozoic dinosaurs will remain unreliable and are unsuitable for inferring cognitive complexity.

@article{doi101002ar70113,
    author = "Caspar, Kai R. and Gutiérrez‐Ibáñez, Cristián and George, Hady and Holtz, Thomas R. and Naish, Darren and Hurlburt, Grant R.",
    title = "Endothermy, neuron counts, and other issues: Further remarks on neurocognitive evolution in fossil vertebrates",
    year = "2025",
    journal = "The Anatomical Record",
    abstract = "Last year, we challenged the view that large-bodied theropod dinosaurs such as Tyrannosaurus rex resembled primates in cognition and behavior, a proposition made by Herculano-Houzel in 2023. More recently, Jensen et al. have criticized our work on this topic, raising methodological and conceptual issues. Central to their argument is the assumption that tachymetabolic endotherms should be expected to converge in neurocognitive traits, which follows the recently proposed endothermic brain hypothesis. We here respond to their critique, address critical misconceptions, and argue that none of the points raised by Jensen et al. challenge the conclusions we have drawn. We show that the endothermic brain hypothesis lacks robust support from the fossil record. As of now, no compelling evidence suggests that endothermy coevolved with enlarged brains or elevated neuron densities in either the avian or mammalian lineage. Various fossil groups containing endothermic taxa retain plesiomorphic endocast traits and do not converge with birds and mammals in the relative size and proportions of their brains. Furthermore, we elaborate on our discussion on (forebrain) neuron counts as correlates of cognitive performance and highlight that neuron numbers evolve in tandem with body mass in birds and mammals, suggesting that comparatively high neuron number estimates for some Mesozoic dinosaurs do not require explanations that orbit around exceptional cognitive abilities. Despite these disagreements, we identify significant overlap in opinion between Jensen et al. and ourselves, including in the position that neuron count estimates for Mesozoic dinosaurs will remain unreliable and are unsuitable for inferring cognitive complexity.",
    url = "https://doi.org/10.1002/ar.70113",
    doi = "10.1002/ar.70113",
    openalex = "W4417503716",
    references = "chiarenza2024early, doi101002ar70074, doi101002cne70056, doi101016jtics202408002, doi101017jpa202510121"
}

Dinosaurs dominated Mesozoic terrestrial ecosystems for ∼160 million years, but their biogeographic origin remains poorly understood. The earliest unequivocal dinosaur fossils appear in the Carnian (∼230 Ma) of southern South America and Africa, leading most authors to propose southwestern Gondwana as the likely center of origin. However, the high taxonomic and morphological diversity of these earliest assemblages suggests a more ancient evolutionary history that is currently unsampled. Phylogenetic uncertainty at the base of Dinosauria, combined with the subsequent appearance of dinosaurs throughout Laurasia in their early evolutionary history, further complicates this picture. Here, we estimate the distribution of early dinosaurs and their archosaurian relatives under a phylogenetic maximum likelihood framework, testing alternative topological arrangements and incorporating potential abiotic barriers to dispersal into our biogeographic models. For the first time, we include spatiotemporal sampling heterogeneity in these models, which frequently supports a low-latitude Gondwanan origin for dinosaurs. These results are best supported when silesaurids are constrained as early-diverging ornithischians, which is likely because this topology accounts for the otherwise substantial ornithischian ghost lineage, explaining the group's absence from the fossil record prior to the Early Jurassic. Our results suggest that the archosaur radiation also took place within low-latitude Gondwana following the end-Permian extinction before lineages dispersed across Pangaea into ecologically and climatically distinct provinces during the Late Triassic. Mesozoic terrestrial vertebrates are under-sampled at low paleolatitudes, and our findings suggest that heterogeneous sampling has hitherto obscured the true paleobiogeographic origin of dinosaurs and their kin.

@article{doi101016jcub202412053,
    author = "Heath, Joel A and Cooper, Natalie and Upchurch, Paul and Mannion, Philip D.",
    title = "Accounting for sampling heterogeneity suggests a low paleolatitude origin for dinosaurs",
    year = "2025",
    journal = "Current Biology",
    abstract = "Dinosaurs dominated Mesozoic terrestrial ecosystems for ∼160 million years, but their biogeographic origin remains poorly understood. The earliest unequivocal dinosaur fossils appear in the Carnian (∼230 Ma) of southern South America and Africa, leading most authors to propose southwestern Gondwana as the likely center of origin. However, the high taxonomic and morphological diversity of these earliest assemblages suggests a more ancient evolutionary history that is currently unsampled. Phylogenetic uncertainty at the base of Dinosauria, combined with the subsequent appearance of dinosaurs throughout Laurasia in their early evolutionary history, further complicates this picture. Here, we estimate the distribution of early dinosaurs and their archosaurian relatives under a phylogenetic maximum likelihood framework, testing alternative topological arrangements and incorporating potential abiotic barriers to dispersal into our biogeographic models. For the first time, we include spatiotemporal sampling heterogeneity in these models, which frequently supports a low-latitude Gondwanan origin for dinosaurs. These results are best supported when silesaurids are constrained as early-diverging ornithischians, which is likely because this topology accounts for the otherwise substantial ornithischian ghost lineage, explaining the group's absence from the fossil record prior to the Early Jurassic. Our results suggest that the archosaur radiation also took place within low-latitude Gondwana following the end-Permian extinction before lineages dispersed across Pangaea into ecologically and climatically distinct provinces during the Late Triassic. Mesozoic terrestrial vertebrates are under-sampled at low paleolatitudes, and our findings suggest that heterogeneous sampling has hitherto obscured the true paleobiogeographic origin of dinosaurs and their kin.",
    url = "https://doi.org/10.1016/j.cub.2024.12.053",
    doi = "10.1016/j.cub.2024.12.053",
    openalex = "W4406758949",
    references = "doi101016jjsames2021103341, doi101016jpgeola202307002, doi101038s4158602205133x, doi101073pnas1319091111, doi101093bioinformaticsbty633, doi101093sysbio461195, doi101093sysbiosys029, doi101093sysbiosyt040, doi101093sysbiosyu056, doi101109tac19741100705, doi101111j2041210x201100169x, doi1021425f55419694, doi1023073802723"
}

Whether non-avian dinosaurs were in decline prior to their extinction 66 million years ago remains a contentious topic. This uncertainty arises from spatiotemporal sampling inconsistency and data absence, which cause challenges in distinguishing between genuine biological trends and sampling artifacts. Consequently, there is an inherent interest in better quantifying the quality of the data and concomitant biases of the dinosaur fossil record. To elucidate the structure of this record and the nature of the biases impacting it, we integrate paleoclimatic, geographic, and fossil data within a Bayesian occupancy modeling framework to simultaneously estimate the probability of dinosaurs occupying and being detected in sites across North America throughout the latest Cretaceous for the first time. We find that apparent declines in occupancy generated from the raw fossil record do not match modeled occupancy probability, which generally remained stable throughout the latest Cretaceous. Instead, they coincide with decreased probability of detecting dinosaur occurrences, despite high overall sampling during this interval. By incorporating model covariates, we additionally reveal that detection probability is directly and significantly influenced by the available area of geological outcrop and modern land cover. Our findings offer evidence that traditional comparisons of diversity estimates between time intervals are likely inaccurate due to underlying structural issues in the geological record operating at both local and regional scales. This study underscores the utility of occupancy modeling as a novel approach in paleobiology for quantifying the impact of heterogeneous sampling on the available fossil record.

@article{doi101016jcub202503025,
    author = "Dean, Christopher D. and Chiarenza, Alfio Alessandro and Doser, Jeffrey W. and Farnsworth, Alexander and Jones, Lewis A. and Lyster, Sinead and Outhwaite, Charlotte L. and Valdes, Paul J. and Butler, Richard J. and Mannion, Philip D.",
    title = "The structure of the end-Cretaceous dinosaur fossil record in North America",
    year = "2025",
    journal = "Current Biology",
    abstract = "Whether non-avian dinosaurs were in decline prior to their extinction 66 million years ago remains a contentious topic. This uncertainty arises from spatiotemporal sampling inconsistency and data absence, which cause challenges in distinguishing between genuine biological trends and sampling artifacts. Consequently, there is an inherent interest in better quantifying the quality of the data and concomitant biases of the dinosaur fossil record. To elucidate the structure of this record and the nature of the biases impacting it, we integrate paleoclimatic, geographic, and fossil data within a Bayesian occupancy modeling framework to simultaneously estimate the probability of dinosaurs occupying and being detected in sites across North America throughout the latest Cretaceous for the first time. We find that apparent declines in occupancy generated from the raw fossil record do not match modeled occupancy probability, which generally remained stable throughout the latest Cretaceous. Instead, they coincide with decreased probability of detecting dinosaur occurrences, despite high overall sampling during this interval. By incorporating model covariates, we additionally reveal that detection probability is directly and significantly influenced by the available area of geological outcrop and modern land cover. Our findings offer evidence that traditional comparisons of diversity estimates between time intervals are likely inaccurate due to underlying structural issues in the geological record operating at both local and regional scales. This study underscores the utility of occupancy modeling as a novel approach in paleobiology for quantifying the impact of heterogeneous sampling on the available fossil record.",
    url = "https://doi.org/10.1016/j.cub.2025.03.025",
    doi = "10.1016/j.cub.2025.03.025",
    openalex = "W4409261299",
    references = "doi101098rsbl20240443"
}

@article{doi101016jgloplacha2025104960,
    author = "Wang, Yan and Cao, Jian and Zhi, Dongming and Tang, Yong and Zhang, Chenjia and An, Xie",
    title = "Molecular fossil responses to Toarcian (Early Jurassic) climate warming in the high-latitude lacustrine Junggar Basin, China",
    year = "2025",
    journal = "Global and Planetary Change",
    url = "https://doi.org/10.1016/j.gloplacha.2025.104960",
    doi = "10.1016/j.gloplacha.2025.104960",
    openalex = "W4411554292",
    references = "doi101144sp5382022323"
}

Two hundred years after the naming of the first dinosaur, taxonomic studies remain an important component of dinosaur research. Around 50 new dinosaurs are named each year and are discovered from across the globe. The rate of new dinosaur discovery shows no signs of slowing, but not all geographical areas and temporal windows have been equally investigated. The potential for new dinosaur discoveries in India and Africa seems particularly high, while the Carnian, when dinosaurs probably originated, and the Middle Jurassic, when the major clades diversified, offer the best opportunities to make discoveries that will fundamentally change our understanding of dinosaur evolution. A major challenge to the discovery of new dinosaurs is funding. Frontier fieldwork is sometimes viewed as too risky to fund, while basic taxonomic work is considered to lack impact. As a consequence, we risk an 'extinction of experience', where researchers have limited training in the basic field- and specimen-based research that underpins our discipline. Going forward, new remote sensing techniques may help to find prospective areas, while three-dimensional scanning apps on smartphones will allow us to quickly record field data. Artificial intelligence is likely to be used increasingly for computed tomography segmentation and identification of problematic fossils.

@article{doi101098rsbl20250045,
    author = "Maidment, Susannah C. R. and Butler, Richard J.",
    title = "New frontiers in dinosaur exploration",
    year = "2025",
    journal = "Biology Letters",
    abstract = "Two hundred years after the naming of the first dinosaur, taxonomic studies remain an important component of dinosaur research. Around 50 new dinosaurs are named each year and are discovered from across the globe. The rate of new dinosaur discovery shows no signs of slowing, but not all geographical areas and temporal windows have been equally investigated. The potential for new dinosaur discoveries in India and Africa seems particularly high, while the Carnian, when dinosaurs probably originated, and the Middle Jurassic, when the major clades diversified, offer the best opportunities to make discoveries that will fundamentally change our understanding of dinosaur evolution. A major challenge to the discovery of new dinosaurs is funding. Frontier fieldwork is sometimes viewed as too risky to fund, while basic taxonomic work is considered to lack impact. As a consequence, we risk an 'extinction of experience', where researchers have limited training in the basic field- and specimen-based research that underpins our discipline. Going forward, new remote sensing techniques may help to find prospective areas, while three-dimensional scanning apps on smartphones will allow us to quickly record field data. Artificial intelligence is likely to be used increasingly for computed tomography segmentation and identification of problematic fossils.",
    url = "https://doi.org/10.1098/rsbl.2025.0045",
    doi = "10.1098/rsbl.2025.0045",
    openalex = "W4409965177",
    references = "doi101016jtree201309012, doi1010801477201920242345333, doi101093zoolinneanzlab072, doi101098rsbl20240443, doi101098rsbl20250045, doi101098rspb20080715, doi101098rspb20121745, doi101111j1469185x200900094x, doi101111j2041210x201200223x, doi101126science28253921298, doi101139cjes20230037, doi10157900447447200837114ecitbs20co2, doi1054991jop202115, openalexw3215057009, sereno1997the"
}

Abstract Inferred biotic exchanges between Europe and Africa during the Cretaceous have been used to support the hypothesis that the complete separation of Europe from Gondwana postdated the split of the remaining Laurasian landmasses from Gondwana. Under this framework, Europe, conceptualized as part of a proposed ‘Eurogondwana’, is thought to have maintained biogeographic connections with Africa well into the Cretaceous. A key piece of evidence underpinning this hypothesis has been the crocodyliform Doratodon carcharidens from the Late Cretaceous of Europe, previously interpreted as closely related to Gondwanan taxa. However, the material attributed to this species is fragmentary, and its skeletal anatomy—critical for phylogenetic inference—remains poorly understood. Here we describe a new partial skull of Doratodon carcharidens which represents some of the most complete material of ‘Gondwanan’ taxa in the European Cretaceous. Our updated phylogenetic analysis unexpectedly and robustly places D. carcharidens among the Laurasian clade Paralligatoridae and reveals that morphological similarities to Gondwanan ziphosuchians, such as ziphodont dentition, are the result of ecomorphological convergence rather than shared ancestry. By reinterpreting the systematic position of further taxa representing biogeographic enigma, such as Ogresuchus furatus, our phylogeny implies a major role of the primary breakup of Pangea into Laurasia and Gondwana for crocodyliform divergence. A critical reassessment of the purported evidence for ‘Gondwanan’ fish and tetrapod immigrants in Europe reveals that it is largely based on highly fragmentary and sporadic specimens, as well as weakly supported phylogenetic hypotheses. Given the sparse and uneven Jurassic and Cretaceous fossil record in both Europe and Africa, it remains plausible that taxa previously interpreted as Gondwanan dispersers instead represent vicariant relicts. Our results conflict with recent paleobiogeographic scenarios, highlight the absence of compelling evidence for the Eurogondwana hypothesis and instead support a primary Gondwana-Laurasia split.

@misc{doi10110120250825671775,
    author = "Szegszárdi, Máté and Ősi, Attila and Rabi, Márton",
    title = "Cretaceous crocodyliform reconciles conflicting evidence on the Mesozoic paleogeography of Europe during the Gondwana-Laurasia split",
    year = "2025",
    booktitle = "bioRxiv (Cold Spring Harbor Laboratory)",
    abstract = "Abstract Inferred biotic exchanges between Europe and Africa during the Cretaceous have been used to support the hypothesis that the complete separation of Europe from Gondwana postdated the split of the remaining Laurasian landmasses from Gondwana. Under this framework, Europe, conceptualized as part of a proposed ‘Eurogondwana’, is thought to have maintained biogeographic connections with Africa well into the Cretaceous. A key piece of evidence underpinning this hypothesis has been the crocodyliform Doratodon carcharidens from the Late Cretaceous of Europe, previously interpreted as closely related to Gondwanan taxa. However, the material attributed to this species is fragmentary, and its skeletal anatomy—critical for phylogenetic inference—remains poorly understood. Here we describe a new partial skull of Doratodon carcharidens which represents some of the most complete material of ‘Gondwanan’ taxa in the European Cretaceous. Our updated phylogenetic analysis unexpectedly and robustly places D. carcharidens among the Laurasian clade Paralligatoridae and reveals that morphological similarities to Gondwanan ziphosuchians, such as ziphodont dentition, are the result of ecomorphological convergence rather than shared ancestry. By reinterpreting the systematic position of further taxa representing biogeographic enigma, such as Ogresuchus furatus, our phylogeny implies a major role of the primary breakup of Pangea into Laurasia and Gondwana for crocodyliform divergence. A critical reassessment of the purported evidence for ‘Gondwanan’ fish and tetrapod immigrants in Europe reveals that it is largely based on highly fragmentary and sporadic specimens, as well as weakly supported phylogenetic hypotheses. Given the sparse and uneven Jurassic and Cretaceous fossil record in both Europe and Africa, it remains plausible that taxa previously interpreted as Gondwanan dispersers instead represent vicariant relicts. Our results conflict with recent paleobiogeographic scenarios, highlight the absence of compelling evidence for the Eurogondwana hypothesis and instead support a primary Gondwana-Laurasia split.",
    url = "https://doi.org/10.1101/2025.08.25.671775",
    doi = "10.1101/2025.08.25.671775",
    openalex = "W4413800217",
    references = "doi101098rsbl20240429"
}

Abstract Bird seasonal migration is a remarkable biogeographic phenomenon, yet its deep‐time origin(s) and evolutionary history remain poorly understood, with the bird fossil record largely overlooked. This study explores the predictability of bird migratory behaviour from the oxygen isotope composition of their bone apatite phosphate (δ 18 O p), a promising approach in this regard because: (i) sedentary and migratory birds tend to occupy distinct climatic niches year‐round; (ii) their δ 18 O p values primarily reflect the climate‐driven isotopic composition of their drinking water; and (iii) this isotopic signature can persist through fossilisation. Bone tissues were categorised based on their potential to yield spatio‐temporally distinct climatic records: early bone tissues (EBT), deposited before somatic maturity, and late bone tissues (LBT), formed through bone remodelling over the lifespan. The predictability of migratory behaviour was theoretically assessed by modelling tissue‐specific δ 18 O p values for thousands of birds across 77 migratory and sedentary species, using tracking and observational data along with a revised phosphate‐water fractionation equation. These theoretical results were confronted with data from 11 extant bird species, obtained using a new experimental framework combining histological and isotopic analyses. A significantly positive correlation between δ 18 O p and the proportion of LBT in bone samples was observed both theoretically and experimentally in migratory birds—particularly in long‐distance migrants—and is predicted to be virtually absent in sedentary species at temperate latitudes. Migratory birds that died outside their natal sites can also be identified when their δ 18 O p,EBT values fall outside the range observed in local juvenile and sedentary birds. We conclude that bird migratory behaviour can be inferred from the δ 18 O p values of their skeletal remains, provided the individuals migrated across sufficiently contrasting climatic zones. While this approach cannot detect all migratory behaviours—such as short‐distance or longitudinal movements—it is unlikely to misclassify sedentary birds as migratory at temperate latitudes. We therefore argue that this approach can be extended to well‐preserved fossil bones to infer past bird migratory behaviours, as long as the palaeoclimatic context is carefully considered. More broadly, this study establishes a framework for inferring migratory behaviour in any vertebrate from non‐fully remodelled biomineralised remains.

@article{doi1011112041210x70211,
    author = "Duhamel, Anaïs and Canoville, Aurore and Vinçon‐Laugier, Arnauld and Joseph, Julien and Fourel, François and Lécuyer, Christophe and Amiot, Romain and Louchart, Antoine",
    title = "Inferring bird migration from bone isotopes and histology: A fossil‐friendly methodological framework",
    year = "2025",
    journal = "Methods in Ecology and Evolution",
    abstract = "Abstract Bird seasonal migration is a remarkable biogeographic phenomenon, yet its deep‐time origin(s) and evolutionary history remain poorly understood, with the bird fossil record largely overlooked. This study explores the predictability of bird migratory behaviour from the oxygen isotope composition of their bone apatite phosphate (δ 18 O p), a promising approach in this regard because: (i) sedentary and migratory birds tend to occupy distinct climatic niches year‐round; (ii) their δ 18 O p values primarily reflect the climate‐driven isotopic composition of their drinking water; and (iii) this isotopic signature can persist through fossilisation. Bone tissues were categorised based on their potential to yield spatio‐temporally distinct climatic records: early bone tissues (EBT), deposited before somatic maturity, and late bone tissues (LBT), formed through bone remodelling over the lifespan. The predictability of migratory behaviour was theoretically assessed by modelling tissue‐specific δ 18 O p values for thousands of birds across 77 migratory and sedentary species, using tracking and observational data along with a revised phosphate‐water fractionation equation. These theoretical results were confronted with data from 11 extant bird species, obtained using a new experimental framework combining histological and isotopic analyses. A significantly positive correlation between δ 18 O p and the proportion of LBT in bone samples was observed both theoretically and experimentally in migratory birds—particularly in long‐distance migrants—and is predicted to be virtually absent in sedentary species at temperate latitudes. Migratory birds that died outside their natal sites can also be identified when their δ 18 O p,EBT values fall outside the range observed in local juvenile and sedentary birds. We conclude that bird migratory behaviour can be inferred from the δ 18 O p values of their skeletal remains, provided the individuals migrated across sufficiently contrasting climatic zones. While this approach cannot detect all migratory behaviours—such as short‐distance or longitudinal movements—it is unlikely to misclassify sedentary birds as migratory at temperate latitudes. We therefore argue that this approach can be extended to well‐preserved fossil bones to infer past bird migratory behaviours, as long as the palaeoclimatic context is carefully considered. More broadly, this study establishes a framework for inferring migratory behaviour in any vertebrate from non‐fully remodelled biomineralised remains.",
    url = "https://doi.org/10.1111/2041-210x.70211",
    doi = "10.1111/2041-210x.70211",
    openalex = "W4417033557",
    references = "doi101126scienceadt5189"
}

ABSTRACT Until now, the significance of microbial mats in preservation of dinosaur tracks and in reconstructing the palaeoenvironment in which dinosaurs roamed was rarely studied. Dinosaur tracks are commonly found close to ancient aquatic bodies where moist sediment had once allowed footstep registration. At such sites, epibenthic or endobenthic microbial mats may have developed as well and may have led to exquisite track preservation. Microbial mats in coastal, lacustrine or flood plain environments cause ‘microbially induced sedimentary structures—MISS’, which are micobialites found in sandy or evaporitic settings. The microbial structures record environmental parameters including meteorological conditions that existed at the time of burial. The aim of this contribution is to give an overview on track morphologies and track distribution coinciding with ancient mat type and palaeoenvironmental situation. In concert, this information assembles a set of palaeoenvironmental and taphonomic parameters characteristic for lagerstätten of well‐preserved tracks. Twelve Jurassic and Cretaceous track sites were investigated, all located in Utah and Colorado, United States. A great variety of MISS including ‘multidirectional ripple marks’, ‘mat chips’, ‘erosional remnants and pockets’, ‘petees’ and others document the occurrence of endobenthic and epibenthic microbial mats once developed in coastal settings of semi‐arid tropical and humid tropical palaeoclimates. Tattered mat surfaces document degradation of microbial mats at the end of the ancient growth season. Epibenthic mat types include planar, spongy and petee mats. These epibenthic mats as well as the infield view less pronounced endobenthic mats were either healthy or desiccated by the time of burial. The type of microbial mat and its condition during footprint registration affected the morphologies of the tracks. Track morphologies include deep footprints with only few anatomical details preserved in ancient, epibenthic microbial mats of planar and of spongy types. Moist mats offered a better medium for registration than dry, brittle mats. Petee microbial mats, originally formed in sabkha settings, were thin and did not allow a well‐contoured footprint to form. Surprisingly, fossil endobenthic microbial mats display relatively well‐preserved tracks. Degrading of the ancient microbial mats was accompanied by the release of mat chips, disintegrating a good part of track information. Pedestal tracks are the result of erosion around tracks that were protected by a microbial mat filling in the footprints. A variety of undertracks were found that allow conclusions on the water content of the buried fossil microbial mats. The track morphologies offer a wider spectrum of information on environment and track producers than tracks preserved in pure sand substrates would. A short exposure time of the ancient surface limited postdepositional disturbance of tracks by weathering, continuous mat growth, baffling and trapping or subsequent dinoturbation. Minimum exposure times ranged from a few hours or days (duration of development of endobenthic mats) to a few months (duration of development of epibenthic mats). These palaeoenvironmental and lithological characteristics of the studied dinosaur track sites may be representative of many exquisite track sites and may assist the future detection of tracks in palaeontological field survey.

@article{doi101111sed70037,
    author = "Noffke, Nora and Murphey, Paul C. and Buntin, Roger C. and Lockley, Martin G.",
    title = "Microbial mats in dinosaur ichnocoenoses",
    year = "2025",
    journal = "Sedimentology",
    abstract = "ABSTRACT Until now, the significance of microbial mats in preservation of dinosaur tracks and in reconstructing the palaeoenvironment in which dinosaurs roamed was rarely studied. Dinosaur tracks are commonly found close to ancient aquatic bodies where moist sediment had once allowed footstep registration. At such sites, epibenthic or endobenthic microbial mats may have developed as well and may have led to exquisite track preservation. Microbial mats in coastal, lacustrine or flood plain environments cause ‘microbially induced sedimentary structures—MISS’, which are micobialites found in sandy or evaporitic settings. The microbial structures record environmental parameters including meteorological conditions that existed at the time of burial. The aim of this contribution is to give an overview on track morphologies and track distribution coinciding with ancient mat type and palaeoenvironmental situation. In concert, this information assembles a set of palaeoenvironmental and taphonomic parameters characteristic for lagerstätten of well‐preserved tracks. Twelve Jurassic and Cretaceous track sites were investigated, all located in Utah and Colorado, United States. A great variety of MISS including ‘multidirectional ripple marks’, ‘mat chips’, ‘erosional remnants and pockets’, ‘petees’ and others document the occurrence of endobenthic and epibenthic microbial mats once developed in coastal settings of semi‐arid tropical and humid tropical palaeoclimates. Tattered mat surfaces document degradation of microbial mats at the end of the ancient growth season. Epibenthic mat types include planar, spongy and petee mats. These epibenthic mats as well as the infield view less pronounced endobenthic mats were either healthy or desiccated by the time of burial. The type of microbial mat and its condition during footprint registration affected the morphologies of the tracks. Track morphologies include deep footprints with only few anatomical details preserved in ancient, epibenthic microbial mats of planar and of spongy types. Moist mats offered a better medium for registration than dry, brittle mats. Petee microbial mats, originally formed in sabkha settings, were thin and did not allow a well‐contoured footprint to form. Surprisingly, fossil endobenthic microbial mats display relatively well‐preserved tracks. Degrading of the ancient microbial mats was accompanied by the release of mat chips, disintegrating a good part of track information. Pedestal tracks are the result of erosion around tracks that were protected by a microbial mat filling in the footprints. A variety of undertracks were found that allow conclusions on the water content of the buried fossil microbial mats. The track morphologies offer a wider spectrum of information on environment and track producers than tracks preserved in pure sand substrates would. A short exposure time of the ancient surface limited postdepositional disturbance of tracks by weathering, continuous mat growth, baffling and trapping or subsequent dinoturbation. Minimum exposure times ranged from a few hours or days (duration of development of endobenthic mats) to a few months (duration of development of epibenthic mats). These palaeoenvironmental and lithological characteristics of the studied dinosaur track sites may be representative of many exquisite track sites and may assist the future detection of tracks in palaeontological field survey.",
    url = "https://doi.org/10.1111/sed.70037",
    doi = "10.1111/sed.70037",
    openalex = "W4413307001",
    references = "doi102110jsr201957"
}

Polar ecosystems are structured and enriched by birds, which nest there seasonally and serve as keystone ecosystem members. Despite the ecological importance of polar birds, the origins of high-latitude nesting strategies remain obscured by a sparse fossil record. We report an extreme-latitude Arctic avialan assemblage from the Prince Creek Formation of Alaska-the northernmost Late Cretaceous terrestrial ecosystem. Numerous three-dimensionally preserved fossils constitute one of the most taxonomically rich Late Cretaceous avialan assemblages, including members of Hesperornithes, Ichthyornithes, and near-crown or crown birds (Neornithes), recording a previously undocumented interval in avialan evolution. Abundant perinatal fossils represent the oldest evidence of birds nesting at polar latitudes, which demonstrates that birds began using seasonal polar environments for breeding during the Cretaceous, long before their modern descendants.

@article{doi101126scienceadt5189,
    author = "Wilson, Lauren N. and Ksepka, Daniel T. and Wilson, John P. and Gardner, Jacob D. and Erickson, Gregory M. and Brinkman, Donald B. and Brown, Caleb M. and Eberle, Jaelyn J. and Organ, Chris L. and Druckenmiller, Patrick S.",
    title = "Arctic bird nesting traces back to the Cretaceous",
    year = "2025",
    journal = "Science",
    abstract = "Polar ecosystems are structured and enriched by birds, which nest there seasonally and serve as keystone ecosystem members. Despite the ecological importance of polar birds, the origins of high-latitude nesting strategies remain obscured by a sparse fossil record. We report an extreme-latitude Arctic avialan assemblage from the Prince Creek Formation of Alaska-the northernmost Late Cretaceous terrestrial ecosystem. Numerous three-dimensionally preserved fossils constitute one of the most taxonomically rich Late Cretaceous avialan assemblages, including members of Hesperornithes, Ichthyornithes, and near-crown or crown birds (Neornithes), recording a previously undocumented interval in avialan evolution. Abundant perinatal fossils represent the oldest evidence of birds nesting at polar latitudes, which demonstrates that birds began using seasonal polar environments for breeding during the Cretaceous, long before their modern descendants.",
    url = "https://doi.org/10.1126/science.adt5189",
    doi = "10.1126/science.adt5189",
    openalex = "W4410850958",
    references = "doi101016jcub201408034, doi101016jcub202105041, doi101038nature03150, doi101038s41467024468432, doi101073pnas0909493107, doi101093nargkab301, doi101093sysbiosys029, doi101111cla12160, doi101111cla12524, doi1012067481, doi10230730135049, openalexw2607033038"
}

, latex, plaster, resin) endocasts, we measured and compared relative endocranial volumes from dozens of extinct amniote taxa with those (endocasts or brain surface scans) of relevant extant species. Additionally, we offer calculated Encephalization Quotients and neocorticalization from digitized endocasts. Using historical methods of analysis, we find that, on average, neocortocalization of mammals increased over time, which is in agreement with recently published findings. Results also showed that, about 60 million years ago, mammalian neocorticalization averaged about 20%, increasing to a present average of 50%, and reaching a maximum of about 80% in primates within the past 10 million years. These results potentially redefine the allometric boundary between mammals and reptiles and confirm that measurements on a single species can adequately represent the brains of the entire species. We encourage other researchers to use our data, results, and conclusions as a springboard for more updated analyses.

@article{doi107717peerj19826,
    author = "Jerison, Harry J. and Early, Catherine and Farke, Andrew A. and Morhardt, Ashley C.",
    title = "Digitized endocasts and brains: a perspective on measurements and historical analyses of the evolution of 172 fossil and extant amniote specimens",
    year = "2025",
    journal = "PeerJ",
    abstract = ", latex, plaster, resin) endocasts, we measured and compared relative endocranial volumes from dozens of extinct amniote taxa with those (endocasts or brain surface scans) of relevant extant species. Additionally, we offer calculated Encephalization Quotients and neocorticalization from digitized endocasts. Using historical methods of analysis, we find that, on average, neocortocalization of mammals increased over time, which is in agreement with recently published findings. Results also showed that, about 60 million years ago, mammalian neocorticalization averaged about 20\%, increasing to a present average of 50\%, and reaching a maximum of about 80\% in primates within the past 10 million years. These results potentially redefine the allometric boundary between mammals and reptiles and confirm that measurements on a single species can adequately represent the brains of the entire species. We encourage other researchers to use our data, results, and conclusions as a springboard for more updated analyses.",
    url = "https://doi.org/10.7717/peerj.19826",
    doi = "10.7717/peerj.19826",
    openalex = "W4414257717",
    references = "doi1010020471733849, doi101002aja1001800203, doi101002ar25459, doi10100797814615382401, doi10103835016580, doi101038385313a0, doi101098rstb20051736, doi101126science7777856, doi101159000155963, doi101176ajp136101353"
}

The Triassic–Jurassic transition marks a critical interval, witnessing major biotic turnovers, including the rise of dinosaurs and the end-Triassic mass extinction, triggered by the Central Atlantic Magmatic Province. However, the volcanism linked to terrestrial ecosystem disturbance and dinosaur distribution remains poorly constrained. Here we present an integrated dataset of chemostratigraphic and astrochronological records for a continental drill core from the Kunming Basin in Yunnan Province of Southwest China, where rich dinosaur assemblages have been previously identified. Three negative carbon isotope excursions coupled with volcanogenic mercury anomalies confirm pulsed volcanism-induced environmental impacts on this subtropical terrestrial setting and placement of the Triassic–Jurassic boundary. Critically, the earliest regional sauropodomorph fossils occurred at ~200.17 Ma, indicating post-extinction colonization in low palaeolatitudes by medium- to large-bodied dinosaurs. Large-scale volcanism-induced stressors, potentially coupled with increased climate seasonality, likely created ecological opportunities facilitating dinosaur expansion in the earliest Jurassic. Early regional sauropodomorph fossils from 200.17 Ma suggest post-Triassic mass extinction dinosaur colonization in low paleolatitudes, likely due to Central Atlantic Magmatic Province stressors and increased climate seasonality, according to chemostratigraphic and astrochronological analysis of a core from the Kunming Basin in China.

@article{doi101038s43247025030836,
    author = "Chen, Jianbo and Niu, Yi-ning and Ma, Rongyao and Zhou, Yan-ling and Liu, Wen-jie and Wang, Yaming and You, Hai-Lu and Xu, Xing and Shen, Shu-Zhong and Feng, Zhuo",
    title = "Triassic–Jurassic environmental instability on the subtropical eastern Tethyan margin linked to low-latitude dinosaur dispersal",
    year = "2026",
    journal = "Communications Earth \& Environment",
    abstract = "The Triassic–Jurassic transition marks a critical interval, witnessing major biotic turnovers, including the rise of dinosaurs and the end-Triassic mass extinction, triggered by the Central Atlantic Magmatic Province. However, the volcanism linked to terrestrial ecosystem disturbance and dinosaur distribution remains poorly constrained. Here we present an integrated dataset of chemostratigraphic and astrochronological records for a continental drill core from the Kunming Basin in Yunnan Province of Southwest China, where rich dinosaur assemblages have been previously identified. Three negative carbon isotope excursions coupled with volcanogenic mercury anomalies confirm pulsed volcanism-induced environmental impacts on this subtropical terrestrial setting and placement of the Triassic–Jurassic boundary. Critically, the earliest regional sauropodomorph fossils occurred at \textasciitilde 200.17 Ma, indicating post-extinction colonization in low palaeolatitudes by medium- to large-bodied dinosaurs. Large-scale volcanism-induced stressors, potentially coupled with increased climate seasonality, likely created ecological opportunities facilitating dinosaur expansion in the earliest Jurassic. Early regional sauropodomorph fossils from 200.17 Ma suggest post-Triassic mass extinction dinosaur colonization in low paleolatitudes, likely due to Central Atlantic Magmatic Province stressors and increased climate seasonality, according to chemostratigraphic and astrochronological analysis of a core from the Kunming Basin in China.",
    url = "https://doi.org/10.1038/s43247-025-03083-6",
    doi = "10.1038/s43247-025-03083-6",
    openalex = "W7123351308",
    references = "chiarenza2024early, doi101016jcageo201902011, doi101016jcub202412053, doi101016jearscirev2019102880, doi101038299715a0, doi101086648222, doi101098rsbl20240429, doi101126science1161833, doi101126science1234204, doi101126science28554321386, doi1011300091761320020300251tameat20co2, doi101146annurevearth050212124107, doi101146annurevearth081320064052"
}

Machine learning holds great promise for classifying and identifying fossils, and has recently been marshaled to identify trackmakers of dinosaur footprints and address long-standing debates over whether some dinosaur tracks are the oldest birds or ornithopods (duck-billed herbivores and kin) in the fossil record, or alternatively were made by nonavian theropods. Existing methods in paleontology, however, require supervision and a priori labeling of training data by researchers, which can lead to bias. We employ an unsupervised machine learning technique for recognizing inherent patterns in shape data, using a disentangled variational autoencoder network, to a database of 1,974 footprints, spanning a diversity of dinosaurs across their evolutionary history, including modern birds. Our neural network identified eight features of shape variation that most differentiate these tracks: overall load and shape (amount of ground contact area), digit spread, digit attachment, heel load, digit and heel emphasis, loading position, heel position, and left-right load. With the unsupervised process finished, we a posteriori labeled each track based on published expert judgments, plotted them into morphospace, and applied distance metrics to group means and nearest neighbors, which showed 80 to 93% agreement with expert identifications. Controversial Late Triassic-Early Jurassic bird-like tracks group with fossil and modern birds and some Middle Jurassic three-toed tracks with ornithopods, supporting an older origin for these groups than recorded by body fossils. We provide an app, DinoTracker, to make this process accessible, and source code that can be adapted to other cases where paleontologists or biologists are studying patterns of shape variation.

@article{doi101073pnas2527222122,
    author = "Hartmann, Gregor and Blakesley, Tone and dePolo, Paige E. and Brusatte, Stephen L.",
    title = "Identifying variation in dinosaur footprints and classifying problematic specimens via unbiased unsupervised machine learning",
    year = "2026",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "Machine learning holds great promise for classifying and identifying fossils, and has recently been marshaled to identify trackmakers of dinosaur footprints and address long-standing debates over whether some dinosaur tracks are the oldest birds or ornithopods (duck-billed herbivores and kin) in the fossil record, or alternatively were made by nonavian theropods. Existing methods in paleontology, however, require supervision and a priori labeling of training data by researchers, which can lead to bias. We employ an unsupervised machine learning technique for recognizing inherent patterns in shape data, using a disentangled variational autoencoder network, to a database of 1,974 footprints, spanning a diversity of dinosaurs across their evolutionary history, including modern birds. Our neural network identified eight features of shape variation that most differentiate these tracks: overall load and shape (amount of ground contact area), digit spread, digit attachment, heel load, digit and heel emphasis, loading position, heel position, and left-right load. With the unsupervised process finished, we a posteriori labeled each track based on published expert judgments, plotted them into morphospace, and applied distance metrics to group means and nearest neighbors, which showed 80 to 93\% agreement with expert identifications. Controversial Late Triassic-Early Jurassic bird-like tracks group with fossil and modern birds and some Middle Jurassic three-toed tracks with ornithopods, supporting an older origin for these groups than recorded by body fossils. We provide an app, DinoTracker, to make this process accessible, and source code that can be adapted to other cases where paleontologists or biologists are studying patterns of shape variation.",
    url = "https://doi.org/10.1073/pnas.2527222122",
    doi = "10.1073/pnas.2527222122",
    openalex = "W7125705939",
    references = "doi101371journalpone0293021"
}