Ichnology

@misc{hitchcock1848an18,
    author = "Hitchcock, E",
    title = "An attempt to discriminate and describe the animals that made the fossil footmarks of the United States, and especially of New England",
    year = "1848",
    howpublished = "Memoirs of the American Academy of Arts and Sciences, v. 3, p. 129-256",
    note = "talkorigins\_source = {true}; raw\_reference = {Hitchcock, E., 1848, An attempt to discriminate and describe the animals that made the fossil footmarks of the United States, and especially of New England: Memoirs of the American Academy of Arts and Sciences, v. 3, p. 129-256.}"
}

@article{shuler1917dinosaur25,
    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{ballou1922mystery1,
    author = "Ballou, W. H",
    title = "Mystery of the Petrified 'Shoe-Sole 5,000,000 Years Old",
    year = "1922",
    howpublished = "American Weekly, New York Sunday American, p. 2",
    note = "talkorigins\_source = {true}; raw\_reference = {Ballou, W. H., 1922, Mystery of the Petrified 'Shoe-Sole 5,000,000 Years Old': American Weekly, New York Sunday American, p. 2.}"
}

Erosion has laid bare at least eight localities in Somervell County, Texas, showing dinosaur tracks in the Glen Rose limestone. It is with keen regret that this article records the disappearance of one of the most notable of these exhibits, the well known track locality at the fourth crossing of the Paluxy River, about four miles west of the town of Glen Rose. Stream erosion, which brought to view there a superb collection of tracks, continued its work too well and wiped out the exhibit as an eraser wipes out a school­boy's blackboard drawing.

@article{openalexw3190071222,
    author = "Shuler, Ellis W.",
    title = "Dinosaur Tracks At The Fourth Crossing Of The Paluxy River Near Glen Rose, Texas",
    year = "1937",
    journal = "SMU Scholar (Southern Methodist University)",
    abstract = "Erosion has laid bare at least eight localities in Somervell County, Texas, showing dinosaur tracks in the Glen Rose limestone. It is with keen regret that this article records the disappearance of one of the most notable of these exhibits, the well known track locality at the fourth crossing of the Paluxy River, about four miles west of the town of Glen Rose. Stream erosion, which brought to view there a superb collection of tracks, continued its work too well and wiped out the exhibit as an eraser wipes out a school­boy's blackboard drawing.",
    openalex = "W3190071222"
}

@misc{cook1970william5,
    author = "Cook, M. A",
    title = "William J. Meister discovery of human footprint with trilobites in a Cambrian formation of western Utah, in Lammerts, W. E., ed., Why Not Creationism?",
    year = "1970",
    howpublished = "Philadelphia, Presbyterian and Reformed Publishing Company, p. 185-186",
    note = "talkorigins\_source = {true}; raw\_reference = {Cook, M. A., 1970, William J. Meister discovery of human footprint with trilobites in a Cambrian formation of western Utah, in Lammerts, W. E., ed., Why Not Creationism?: Philadelphia, Presbyterian and Reformed Publishing Company, p. 185-186.}"
}

@misc{welles1971dinosaur29,
    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{neufeld1975dinosaur24,
    author = "Neufeld, B",
    title = "Dinosaur tracks and giant men",
    year = "1975",
    howpublished = "Origins, v. 2, no. 2, p. 64- 67",
    note = "talkorigins\_source = {true}; raw\_reference = {Neufeld, B., 1975, Dinosaur tracks and giant men: Origins, v. 2, no. 2, p. 64- 67.}"
}

@misc{craighead1979track6,
    author = "Craighead, F. C",
    title = "Track of the Grizzly",
    year = "1979",
    howpublished = "San Francisco, Sierra Club Books",
    note = "talkorigins\_source = {true}; raw\_reference = {Craighead, F. C., 1979, Track of the Grizzly: San Francisco, Sierra Club Books.}"
}

@misc{conrad1981tripping4,
    author = "Conrad, E. C",
    title = "Tripping over a trilobite",
    year = "1981",
    howpublished = "A study of the Meister tracks: Creation/Evolution, v. 2, p. 30-33",
    note = "talkorigins\_source = {true}; raw\_reference = {Conrad, E. C., 1981, Tripping over a trilobite: A study of the Meister tracks: Creation/Evolution, v. 2, p. 30-33.}"
}

@misc{farlow1981estimates7,
    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.}"
}

@misc{godfrey1981an10,
    author = "Godfrey, L. R",
    title = "An analysis of the creationist film, Footprints in Stone",
    year = "1981",
    howpublished = "Creation/Evolution, v. 2, p. 23-30",
    note = "talkorigins\_source = {true}; raw\_reference = {Godfrey, L. R., 1981, An analysis of the creationist film, Footprints in Stone: Creation/Evolution, v. 2, p. 23-30.}"
}

@misc{hay1982the17,
    author = "Hay, R. L. and Leakey, M",
    title = "The fossil footprints of Laetolil",
    year = "1982",
    howpublished = "Scientific American, v. 246, no. 4, p. 50-57",
    note = "talkorigins\_source = {true}; raw\_reference = {Hay, R. L., and Leakey, M., 1982, The fossil footprints of Laetolil: Scientific American, v. 246, no. 4, p. 50-57.}"
}

@article{milne1983dinosaur,
    author = "Milne, David H. and Schafersman, Steven D.",
    title = "Dinosaur Tracks, Erosion Marks and Midnight Chisel Work (But No Human Footprints) In the Cretaceous Limestone of the Paluxy River Bed, Texas",
    year = "1983",
    journal = "Journal of Geological Education",
    url = "https://doi.org/10.5408/0022-1368-31.2.111",
    doi = "10.5408/0022-1368-31.2.111",
    number = "2",
    openalex = "W207046123",
    pages = "111-123",
    volume = "31"
}

@misc{thulborn1984dinosaur27,
    author = "Thulborn, R. A. and Wade, M",
    title = "Dinosaur trackways in the Winton Formation (Mid-Cretaceous) of Queensland",
    year = "1984",
    howpublished = "Memoirs of the Queensland Museum, v. 21, p. 413-517",
    note = "talkorigins\_source = {true}; raw\_reference = {Thulborn, R. A., and Wade, M., 1984, Dinosaur trackways in the Winton Formation (Mid-Cretaceous) of Queensland: Memoirs of the Queensland Museum, v. 21, p. 413-517.}"
}

@misc{cole1985mantracks2,
    author = "Cole, J. R. and Godfrey, L. R. and Schafersman, S. D",
    title = "Mantracks? The fossils say No!",
    year = "1985",
    howpublished = "Creation/Evolution, v. 5, p. 37-45",
    note = "talkorigins\_source = {true}; raw\_reference = {Cole, J. R., Godfrey, L. R., and Schafersman, S. D., 1985, Mantracks? The fossils say No! : Creation/Evolution, v. 5, p. 37-45.}"
}

@misc{cole1985the3,
    author = "Cole, J. R. and Godfrey, L. R. [E",
    title = "The Paluxy River footprint mystery-- solved",
    year = "1985",
    howpublished = "Creation/Evolution, v. 5, p. 1-56",
    note = "talkorigins\_source = {true}; raw\_reference = {Cole, J. R., and Godfrey, L. R. [E., 1985, The Paluxy River footprint mystery-- solved: Creation/Evolution, v. 5, p. 1-56.}"
}

@misc{godfrey1985foot11,
    author = "Godfrey, L. R",
    title = "Foot Notes of an Anatomist",
    year = "1985",
    howpublished = "Creation/Evolution, v. 5, p. 16-36; in Cole, JR and Godfrey, LR, eds., (1985) The Paluxy River Footprint Mystery- Solved. Creation/Evolution 5 (Special Issue)",
    note = "talkorigins\_source = {true}; raw\_reference = {Godfrey, L. R., 1985, Foot Notes of an Anatomist: Creation/Evolution, v. 5, p. 16-36; in Cole, JR and Godfrey, LR, eds., (1985) The Paluxy River Footprint Mystery- Solved. Creation/Evolution 5 (Special Issue).}"
}

@misc{hastings1985tracking12,
    author = "Hastings, R. J",
    title = "Tracking Those Incredible Creationists, in Cole, J. R., and Godfrey, L. R., eds., The Paluxy River Footprint Mystery-Solved",
    year = "1985",
    howpublished = "p. 5-15; Special Issue. Creation/Evolution 15",
    note = "talkorigins\_source = {true}; raw\_reference = {Hastings, R. J., 1985, Tracking Those Incredible Creationists, in Cole, J. R., and Godfrey, L. R., eds., The Paluxy River Footprint Mystery-Solved: p. 5-15; Special Issue. Creation/Evolution 15.}"
}

The serious study of dinosaur tracks, or applied dinosaur ichnology, is a field with considerable potential for paloebiological and paleoenvironmental interpretation. Despite being a neglected area of study, paleontologists have realized the potential of tracks in enhancing paleobiological interpretations pertaining to taxonomy, locomotion, social behaviour, biostratigraphic zonation and evolution. Where the study has really lagged behind is in its application to paleoenvironmental analysis. Recent studies have shown that tracks provide important, sometimes spectacular, paleogeographic evidence of shoreline configuration, paleoslope, absolute water depth and sediment saturation. In effect they may tell one as much about the paleoenvironment as they do about the trackmaker. In addition they have to be considered seriously for their contribution to the bioor 'dinoturbation' process and for their taphonomic effects. The hitherto unrecognized geographic and stratigraphic abundance of dinosaur (and other) tracks in many regions indicates that they are a persistent rather than occasional feature of the geologic record. As such they warrant greater attention in many paleoenvironmental studies.

@article{doi1023073514457,
    author = "Lockley, Martin G.",
    title = "The Paleobiological and Paleoenvironmental Importance of Dinosaur Footprints",
    year = "1986",
    journal = "Palaios",
    abstract = "The serious study of dinosaur tracks, or applied dinosaur ichnology, is a field with considerable potential for paloebiological and paleoenvironmental interpretation. Despite being a neglected area of study, paleontologists have realized the potential of tracks in enhancing paleobiological interpretations pertaining to taxonomy, locomotion, social behaviour, biostratigraphic zonation and evolution. Where the study has really lagged behind is in its application to paleoenvironmental analysis. Recent studies have shown that tracks provide important, sometimes spectacular, paleogeographic evidence of shoreline configuration, paleoslope, absolute water depth and sediment saturation. In effect they may tell one as much about the paleoenvironment as they do about the trackmaker. In addition they have to be considered seriously for their contribution to the bioor 'dinoturbation' process and for their taphonomic effects. The hitherto unrecognized geographic and stratigraphic abundance of dinosaur (and other) tracks in many regions indicates that they are a persistent rather than occasional feature of the geologic record. As such they warrant greater attention in many paleoenvironmental studies.",
    url = "https://doi.org/10.2307/3514457",
    doi = "10.2307/3514457",
    openalex = "W1970598126",
    references = "coombs1980swimming, doi1010079783642659232, doi1010160025322767900515, doi1010160031018272900491, doi101017s009483730000676x, doi101038207270a0, doi101038278317a0, doi101038282296a0, doi101038297675a0, doi101111j150239311968tb01724x, openalexw2204429280, openalexw2242116350, openalexw2737139879"
}

@misc{farlow1986in8,
    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{hastings1986tracking13,
    author = "Hastings, R. J",
    title = "Tracking those incredible creationists--the trail continues",
    year = "1986",
    howpublished = "Creation/Evolution, v. 5, p. 5-15",
    note = "talkorigins\_source = {true}; raw\_reference = {Hastings, R. J., 1986, Tracking those incredible creationists--the trail continues: Creation/Evolution, v. 5, p. 5-15.}"
}

@book{haubold1986archosaur16,
    author = "Haubold, H",
    title = "Archosaur Footprints at the Terrestrial Triassic-Jurassic Transition, in Padian, K., ed., The Beginning of the Age of Dinosaurs",
    year = "1986",
    publisher = "Cambridge, Cambridge University Press, p. 189-201",
    note = "talkorigins\_source = {true}; raw\_reference = {Haubold, H., 1986, Archosaur Footprints at the Terrestrial Triassic-Jurassic Transition, in Padian, K., ed., The Beginning of the Age of Dinosaurs: Cambridge, Cambridge University Press, p. 189-201.}"
}

@misc{kuban1986a19,
    author = "Kuban, G. J",
    title = "A Summary of the Taylor Site Evidence",
    year = "1986",
    howpublished = "Creation/Evolution, v. 6, no. 1, XVII, p. 10-18",
    note = "talkorigins\_source = {true}; raw\_reference = {Kuban, G. J., 1986, A Summary of the Taylor Site Evidence: Creation/Evolution, v. 6, no. 1, XVII, p. 10-18.}"
}

@article{kuban1986review21,
    author = "Kuban, G. J",
    title = "Review of ICR Impact article 151",
    year = "1986",
    journal = "Origins Research, v. 9, no. 1, p. 10-15",
    note = "talkorigins\_source = {true}; raw\_reference = {Kuban, G. J., 1986, Review of ICR Impact article 151: Origins Research, v. 9, no. 1, p. 10-15.}"
}

@misc{kuban1986the20,
    author = "Kuban, G. J",
    title = {The Taylor Site "man tracks},
    year = "1986",
    howpublished = "Origins Research, v. 9, no. 1, p. 7-9",
    note = {talkorigins\_source = {true}; raw\_reference = {Kuban, G. J., 1986, The Taylor Site "man tracks": Origins Research, v. 9, no. 1, p. 7-9.}}
}

@techreport{lockley1986north23,
    author = "Lockley, M. and Houck, K. and Prince, N. K",
    title = "North America's largest dinosaur trackway site",
    year = "1986",
    howpublished = "Implications for Morrison Formation paleoecology: Geological Society of America Bulletin, v. 97, p. 1163-1176",
    note = "talkorigins\_source = {true}; raw\_reference = {Lockley, M., Houck, K., and Prince, N. K., 1986, North America's largest dinosaur trackway site: Implications for Morrison Formation paleoecology: Geological Society of America Bulletin, v. 97, p. 1163-1176.}"
}

Preface Introduction Part I. The Beginning of the Age of Dinosaurs: The Time and the Setting: 1. Historical aspects of the Triassic-Jurassic boundary problem Edwin H. Colbert 2. Fossil plants and the Triassic-Jurassic boundary Sidney Ash Part II. Late Triassic Vertebrate Taxa and Faunas: 3. Thoughts on the origin of the Theropoda Samuel P. Welles 4. Structure and function of the tarsus in the phytosaurs (Reptilia: Archosauria) J. Michael Parrish 5. On the type material of Coelophysis Cope (Saurischis: Theropoda), and a new specimen from the Petrified Forest of Arizona (Late Triassic: Chinle Formation) Kevin Padian 6. The ichnogenus Atreipus and its significance for Triassic biostratigraphy Paul E. Olsen and Donald Baird 7. The limb posture of kannemeyeriid dicynodonts: functional and ecological considerations Laurie R. Walter 8. A new family of mammals from the lower part of the French Rhaetic Denise Sigogneau-Russell, R. M. Frank and J. Hemmerle 9. Vertebrate paleontology of the Dockum Group, western Texas and eastern New Mexico Phillip A. Murry 10. The Late Triassic Dockum vertebrates: their stratigraphic and paleobiogeographic significance Sankar Chatterjee 11. A new vertenrate fauna from the Dockum Formation (Late Triasssic) of eastern New Mexico J. Michael Parrish and Kenneth Carpenter 12. Vertebrate biostratigraphy of the Late Triassic Chinle Formation, Petrified Forest National Park, Arizona: preliminary results R. A. Long and Kevin Padian Part III. Taxa and Trends Across the Triassic-Jurassic Boundary: 13. Triassic and Jurassic fishes: patterns of diversity Amy R. McCune and Bobb Schaeffer 14. Triassic and Early Jurassic turtles Eugene S. Gaffney 15. Archosaur footprints at the terrestrial Triassic-Jurassic transition Hartmut Haubold 16. Herbivorous adaptations of Late Triassic and Early Jurassic dinosaurs Pater M. Galton 17. Masticatory apparatus of the larger herbivores during Late Triassic and early Jurassic times A. W. Crompton and J. Attridge 18. On Triassic and Jurassic mammals William A. Clemens Part IV. Early Jurassic Vertebrate Taxa and Faunas: 19. The early radiation and phylogenetic relationships of the Jurassic sauropod dinosaurs, based on vertebral anatomy Jose F. Bonaparte 20. Earliest records of Batrachopus from the southwestern United States, and a revision of some early Mesozoic crocodylomorph ichnogenera Paul E. Olsen and Kevin Padian 21. A brief introduction to the Lower Lufeng saurischian fauna (Lower Jurassic: Lufeng, Yunnan, People's Republic of China) A. L. Sun and K. H. Cui 22. Relationships and biostratigraphic significance of the Tritylodontidae (Synapsida) from the Kayenta Formation of northeastern Arizona Hans Dieter Sues 23. Vertebrate biostrarigraphy of the Glen canyon Group in northern Arizona James M. Clark and David E. Fastovsky Part V. Macroevolutionary Patterns of the Triassic-Jurassic Transition: 24. The Late Triassic tetrapod extinction events Michael J. Benton 25. Correlation of continental Late Triassic and Early Jurassic sediments, and patterns of the Triassic-Jurassic tetrapod transition Paul E. Olsen and Hans-Dieter Sues 26. Terrestrial vertebrate faunal succession during the Triassic J. M. Zawiskie Summary and prospectus Taxonomic index Ichnotaxonomic index.

@book{openalexw606525048,
    author = "Padian, Kevin",
    title = "The Beginning of the age of dinosaurs: faunal change across the Triassic-Jurassic boundary",
    year = "1986",
    booktitle = "Cambridge University Press eBooks",
    abstract = "Preface Introduction Part I. The Beginning of the Age of Dinosaurs: The Time and the Setting: 1. Historical aspects of the Triassic-Jurassic boundary problem Edwin H. Colbert 2. Fossil plants and the Triassic-Jurassic boundary Sidney Ash Part II. Late Triassic Vertebrate Taxa and Faunas: 3. Thoughts on the origin of the Theropoda Samuel P. Welles 4. Structure and function of the tarsus in the phytosaurs (Reptilia: Archosauria) J. Michael Parrish 5. On the type material of Coelophysis Cope (Saurischis: Theropoda), and a new specimen from the Petrified Forest of Arizona (Late Triassic: Chinle Formation) Kevin Padian 6. The ichnogenus Atreipus and its significance for Triassic biostratigraphy Paul E. Olsen and Donald Baird 7. The limb posture of kannemeyeriid dicynodonts: functional and ecological considerations Laurie R. Walter 8. A new family of mammals from the lower part of the French Rhaetic Denise Sigogneau-Russell, R. M. Frank and J. Hemmerle 9. Vertebrate paleontology of the Dockum Group, western Texas and eastern New Mexico Phillip A. Murry 10. The Late Triassic Dockum vertebrates: their stratigraphic and paleobiogeographic significance Sankar Chatterjee 11. A new vertenrate fauna from the Dockum Formation (Late Triasssic) of eastern New Mexico J. Michael Parrish and Kenneth Carpenter 12. Vertebrate biostratigraphy of the Late Triassic Chinle Formation, Petrified Forest National Park, Arizona: preliminary results R. A. Long and Kevin Padian Part III. Taxa and Trends Across the Triassic-Jurassic Boundary: 13. Triassic and Jurassic fishes: patterns of diversity Amy R. McCune and Bobb Schaeffer 14. Triassic and Early Jurassic turtles Eugene S. Gaffney 15. Archosaur footprints at the terrestrial Triassic-Jurassic transition Hartmut Haubold 16. Herbivorous adaptations of Late Triassic and Early Jurassic dinosaurs Pater M. Galton 17. Masticatory apparatus of the larger herbivores during Late Triassic and early Jurassic times A. W. Crompton and J. Attridge 18. On Triassic and Jurassic mammals William A. Clemens Part IV. Early Jurassic Vertebrate Taxa and Faunas: 19. The early radiation and phylogenetic relationships of the Jurassic sauropod dinosaurs, based on vertebral anatomy Jose F. Bonaparte 20. Earliest records of Batrachopus from the southwestern United States, and a revision of some early Mesozoic crocodylomorph ichnogenera Paul E. Olsen and Kevin Padian 21. A brief introduction to the Lower Lufeng saurischian fauna (Lower Jurassic: Lufeng, Yunnan, People's Republic of China) A. L. Sun and K. H. Cui 22. Relationships and biostratigraphic significance of the Tritylodontidae (Synapsida) from the Kayenta Formation of northeastern Arizona Hans Dieter Sues 23. Vertebrate biostrarigraphy of the Glen canyon Group in northern Arizona James M. Clark and David E. Fastovsky Part V. Macroevolutionary Patterns of the Triassic-Jurassic Transition: 24. The Late Triassic tetrapod extinction events Michael J. Benton 25. Correlation of continental Late Triassic and Early Jurassic sediments, and patterns of the Triassic-Jurassic tetrapod transition Paul E. Olsen and Hans-Dieter Sues 26. Terrestrial vertebrate faunal succession during the Triassic J. M. Zawiskie Summary and prospectus Taxonomic index Ichnotaxonomic index.",
    url = "https://openalex.org/W606525048",
    openalex = "W606525048"
}

@article{stokes1986alleged26,
    author = "Stokes, W. L",
    title = "Alleged human footprint from Middle Cambrian strata, Milford County, Utah",
    year = "1986",
    journal = "Journal of Geological Education, v. 34, p. 187-190",
    note = "talkorigins\_source = {true}; raw\_reference = {Stokes, W. L., 1986, Alleged human footprint from Middle Cambrian strata, Milford County, Utah: Journal of Geological Education, v. 34, p. 187-190.}"
}

The study of tracks is often regarded as a fringe subdiscipline outside the scientific mainstream. Papers dealing with footprints traditionally appear either in popular magazines like Natural History (Bird 1939, 1944; Brown 1938), or in very obscure publications (Sarjeant 1974). Usually it is only the spectacular discoveries, which are directly applicable to topical debates, that rouse much scientific interest. For example, the discovery of Pliocene hominid tracks (Leakey and Hay 1979) provided unequivocal evidence for the antiquity of bipedalism (cf., Napier 1967). Similarly the tracks of a running theropod allowed for direct estimates of the speed attained by dinosaurs (Farlow 1981), and the tracks of a herd of running theropods fueled debate about gregariousness and stampede behavior (Thulborn and Wade 1984).

@article{doi101017s0094837300008782,
    author = "Lockley, Martin G. and Gillette, David D.",
    title = "Dinosaur tracks symposium signals a renaissance in vertebrate ichnology",
    year = "1987",
    journal = "Paleobiology",
    abstract = "The study of tracks is often regarded as a fringe subdiscipline outside the scientific mainstream. Papers dealing with footprints traditionally appear either in popular magazines like Natural History (Bird 1939, 1944; Brown 1938), or in very obscure publications (Sarjeant 1974). Usually it is only the spectacular discoveries, which are directly applicable to topical debates, that rouse much scientific interest. For example, the discovery of Pliocene hominid tracks (Leakey and Hay 1979) provided unequivocal evidence for the antiquity of bipedalism (cf., Napier 1967). Similarly the tracks of a running theropod allowed for direct estimates of the speed attained by dinosaurs (Farlow 1981), and the tracks of a herd of running theropods fueled debate about gregariousness and stampede behavior (Thulborn and Wade 1984).",
    url = "https://doi.org/10.1017/s0094837300008782",
    doi = "10.1017/s0094837300008782",
    openalex = "W2271526187",
    references = "doi101017s009483730000676x, doi101038261129a0, doi101038278317a0, doi101038scientificamerican047558, doi101130001676061986971163naldts20co2, doi101306212f7be92b2411d78648000102c1865d, doi1023073514457, openalexw2242116350, openalexw2409645054, openalexw2737139879"
}

@book{farlow1987a9,
    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.}"
}

@article{hastings1987new14,
    author = "Hastings, R. J",
    title = "New observations on Paluxy tracks confirm their dinosaurian origin",
    year = "1987",
    journal = "Journal of Geological Education, v. 35, p. 4-15",
    note = "talkorigins\_source = {true}; raw\_reference = {Hastings, R. J., 1987, New observations on Paluxy tracks confirm their dinosaurian origin: Journal of Geological Education, v. 35, p. 4-15.}"
}

@misc{kuban1987the22,
    author = "Kuban, G. J",
    title = {The Texas "Mantrack" Controversy},
    year = "1987",
    howpublished = "[Privately published monograph. P.O. Box 33232, North Royalton, Ohio. 44113]",
    note = {talkorigins\_source = {true}; raw\_reference = {Kuban, G. J., 1987, The Texas "Mantrack" Controversy. [Privately published monograph. P.O. Box 33232, North Royalton, Ohio. 44113].}}
}

@article{weems1987a28,
    author = "Weems, R",
    title = "A Late Triassic footprint fauna from the Culpepper Basin, Northern Virginia (USA)",
    year = "1987",
    journal = "Transactions of the American Philosophical Society, v. 77, no. 1, p. 1-79",
    note = "talkorigins\_source = {true}; raw\_reference = {Weems, R., 1987, A Late Triassic footprint fauna from the Culpepper Basin, Northern Virginia (USA): Transactions of the American Philosophical Society, v. 77, no. 1, p. 1-79.}"
}

@article{lockley1988james,
    author = "Lockley, Martin G.",
    title = "James O. Farlow: A Guide to Lower Cretaceous Dinosaur Footprints and Tracksites of Paluxy River Valley, Somervell County, Texas",
    year = "1988",
    journal = "Journal of Vertebrate Paleontology",
    url = "https://doi.org/10.1080/02724634.1988.10011689",
    doi = "10.1080/02724634.1988.10011689",
    number = "1",
    openalex = "W2044859162",
    pages = "110-112",
    volume = "8",
    references = "doi1010160031018272900491, doi101017s0094837300008782, doi101038229172a0, doi101130001676061986971163naldts20co2, doi1023072424244, doi1023073514457, doi104095105049, openalexw1504554173, openalexw2618301958"
}

@misc{hastings1989creationists15,
    author = "Hastings, R. J",
    title = "Creationists' 'Glen Rose Man' Proves to be a Fish Tooth (as Expected)",
    year = "1989",
    howpublished = "National Council on Science Education Reports, v. 9, no. 3, p. 14-15",
    note = "talkorigins\_source = {true}; raw\_reference = {Hastings, R. J., 1989, Creationists' 'Glen Rose Man' Proves to be a Fish Tooth (as Expected): National Council on Science Education Reports, v. 9, no. 3, p. 14-15.}"
}

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"
}

For dinosaur lovers and tourists alike, this guide explores the palaeontological treasure trove of the western United States. Concentrating on the rich fossil life of the Colorado Plateau region - including parts of Utah, Arizona, and New Mexico - it gives readers the story behind a track record which extends some 300 million years back in time. Readers learn about America's prehistory as they explore a region with one of the best track records of land animals found anywhere in the world. An appendix lists museums and other major repositories of tracks and replicas, and gives details on tracksites open to the public. Lockley leads his readers to the footprints themselves, and shows fossil explorers how these traces can help to interpret the behaviour of dinosaurs.

@article{doi105860choice332752,
    author = "Lockley, Martin G. and Hunt, Adrian P.",
    title = "Dinosaur tracks and other fossil footprints of the western United States",
    year = "1996",
    journal = "Choice Reviews Online",
    abstract = "For dinosaur lovers and tourists alike, this guide explores the palaeontological treasure trove of the western United States. Concentrating on the rich fossil life of the Colorado Plateau region - including parts of Utah, Arizona, and New Mexico - it gives readers the story behind a track record which extends some 300 million years back in time. Readers learn about America's prehistory as they explore a region with one of the best track records of land animals found anywhere in the world. An appendix lists museums and other major repositories of tracks and replicas, and gives details on tracksites open to the public. Lockley leads his readers to the footprints themselves, and shows fossil explorers how these traces can help to interpret the behaviour of dinosaurs.",
    url = "https://doi.org/10.5860/choice.33-2752",
    doi = "10.5860/choice.33-2752",
    openalex = "W1570663375",
    references = "doi1011300091761319910191201fvfitc23co2, openalexw3093435588, openalexw603337959"
}

Abstract The Brazilian Cretaceous basins located at the northeastern region of Brazil present a wide distribution of dinosaur tracks and isolated footprints in many environmental settings: alluvial fans, braided and meandering fluvial floodplains, marginal lake borders and tidal flats. They are mainly theropod and sauropod footprints of Neocomian and Cenomanian ages that are found in Sousa, Uiraúna-Brejo das Freiras, Araripe, Cedro, Malhada Vermelha, Lima Campos and São Luís Basins. The vertebrate ichnofossils are important biogenic sedimentary structures, a picture of the interaction between dinosaur's behavior and the substrate nature, allowing the paleobiological analysis and inferences about the palaeoenvironments. Keywords: Brazilian dinosaur footprintsBrazilian basinsgeological context of footprints ACKNOWLEDGEMENTS To Professor Giuseppe Leonardi for his efforts on developing ichnological research on the Brazilian Cretaceous basins and Dr. Heloisa Vargas Borges, Dr. John Foster, and Dr. Debra Mickelson for their critical review of the manuscript. Financial support for the research was provided by Instituto Virtual de Paleontologia/Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Fundação Universitária José Bonifácio (FUJB), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, grant no. 300571/2003-8) and Universidade Federal do Rio de Janeiro (UFRJ).

@article{doi10108010420940490442368,
    author = "de Souza Carvalho, Ismar",
    title = "Dinosaur Footprints from Northeastern Brazil: Taphonomy and Environmental Setting",
    year = "2004",
    journal = "Ichnos/Ichnos : an international journal for plant and animal traces",
    abstract = "Abstract The Brazilian Cretaceous basins located at the northeastern region of Brazil present a wide distribution of dinosaur tracks and isolated footprints in many environmental settings: alluvial fans, braided and meandering fluvial floodplains, marginal lake borders and tidal flats. They are mainly theropod and sauropod footprints of Neocomian and Cenomanian ages that are found in Sousa, Uiraúna-Brejo das Freiras, Araripe, Cedro, Malhada Vermelha, Lima Campos and São Luís Basins. The vertebrate ichnofossils are important biogenic sedimentary structures, a picture of the interaction between dinosaur's behavior and the substrate nature, allowing the paleobiological analysis and inferences about the palaeoenvironments. Keywords: Brazilian dinosaur footprintsBrazilian basinsgeological context of footprints ACKNOWLEDGEMENTS To Professor Giuseppe Leonardi for his efforts on developing ichnological research on the Brazilian Cretaceous basins and Dr. Heloisa Vargas Borges, Dr. John Foster, and Dr. Debra Mickelson for their critical review of the manuscript. Financial support for the research was provided by Instituto Virtual de Paleontologia/Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Fundação Universitária José Bonifácio (FUJB), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, grant no. 300571/2003-8) and Universidade Federal do Rio de Janeiro (UFRJ).",
    url = "https://doi.org/10.1080/10420940490442368",
    doi = "10.1080/10420940490442368",
    openalex = "W2034015072",
    references = "doi1023073514457"
}

Dinosaur tracks and trackways yield invaluable information as to the identity, size, and gait of the trackmaker and the conditions of the media (‫؍‬substrate) it traversed.Correctly interpreting tracks requires consideration of their three-dimensional morphology.Laboratory-controlled simulations were conducted to investigate the subsurface track morphology formed from differently shaped feet, as the shape of the footprint deteriorates with depth.A circular, triangular, and a tridactyl dinosaur foot-shaped template, or indenter, were indented vertically into two types of sand, with four moisture contents-dry, 10%, 20%, and saturated.The morphology of all three indenters was preserved most accurately in the moist sand.Tracks in dry and saturated sand were distorted by a greater degree of media deformation.Digit imprints of tridactyl tracks were only clearly discernible in near-surface layers and were deformed by shear zones or inward movement of sediment in dry and saturated sand.The long digits of the template produced the greatest degree of outward displacement, and tracks became wider with depth and deepest in the heel region.This was most distinct in dry sand, where extensive shear zones in cross section demonstrated the outward and upward movement of sediment.All tracks in saturated sand were characterized by considerable downward displacement of sediment and features related to the upward pull of sediment as the templates were withdrawn.These diagnostic features allow vertebrate tracks to be differentiated from nonbiogenic, soft-sediment deformation.Fossil tracks studied from the Middle Jurassic succession of the Cleveland Basin, Yorkshire, demonstrate affinities to the experimental tracks formed in saturated sand.

@article{doi102110palo2007p07070r,
    author = "Jackson, Stephen and Whyte, M. A. and Romano, M.",
    title = "LABORATORY-CONTROLLED SIMULATIONS OF DINOSAUR FOOTPRINTS IN SAND: A KEY TO UNDERSTANDING VERTEBRATE TRACK FORMATION AND PRESERVATION",
    year = "2009",
    journal = "Palaios",
    abstract = "Dinosaur tracks and trackways yield invaluable information as to the identity, size, and gait of the trackmaker and the conditions of the media (‫؍‬substrate) it traversed.Correctly interpreting tracks requires consideration of their three-dimensional morphology.Laboratory-controlled simulations were conducted to investigate the subsurface track morphology formed from differently shaped feet, as the shape of the footprint deteriorates with depth.A circular, triangular, and a tridactyl dinosaur foot-shaped template, or indenter, were indented vertically into two types of sand, with four moisture contents-dry, 10\%, 20\%, and saturated.The morphology of all three indenters was preserved most accurately in the moist sand.Tracks in dry and saturated sand were distorted by a greater degree of media deformation.Digit imprints of tridactyl tracks were only clearly discernible in near-surface layers and were deformed by shear zones or inward movement of sediment in dry and saturated sand.The long digits of the template produced the greatest degree of outward displacement, and tracks became wider with depth and deepest in the heel region.This was most distinct in dry sand, where extensive shear zones in cross section demonstrated the outward and upward movement of sediment.All tracks in saturated sand were characterized by considerable downward displacement of sediment and features related to the upward pull of sediment as the templates were withdrawn.These diagnostic features allow vertebrate tracks to be differentiated from nonbiogenic, soft-sediment deformation.Fossil tracks studied from the Middle Jurassic succession of the Cleveland Basin, Yorkshire, demonstrate affinities to the experimental tracks formed in saturated sand.",
    url = "https://doi.org/10.2110/palo.2007.p07-070r",
    doi = "10.2110/palo.2007.p07-070r",
    openalex = "W2089482175",
    references = "doi101016jpalaeo200412022, doi101016s001678780180047x, doi10103820167, doi101098rstb19970035, doi101111j146979981991tb04794x, doi101144gslsp20042280106, doi101144pygs543185, doi1023073514457, doi1023073514816, doi105860choice273305, doi105860choice393984, openalexw2764433274"
}

@article{crossref2010photogrammetry,
    title = "Photogrammetry in the service of ichnology: dinosaur footprints in the Italian Alps",
    year = "2010",
    journal = "The Photogrammetric Record",
    url = "https://doi.org/10.1111/j.1477-9730.2010.00589.x",
    doi = "10.1111/j.1477-9730.2010.00589.x",
    number = "131",
    openalex = "W4246259860",
    pages = "222-223",
    volume = "25"
}

The laboratory-controlled simulations of dinosaur footprints in this study revealed characteristic track features that could be used to identify the consistency of sand substrates and provide an insight into the paleoenvironment. A model foot of Hypsilophodon foxii was indented into three sands of four different moisture (= water) contents. The two intermediate moist states were characterized by shallow tridactyl impressions, in which only digits II–IV were impressed, showing details of padding and claws. Where the foot penetrated more deeply, in the dry and saturated states, the hallux and heel were also impressed; in these cases, the foot detail was not preserved accurately and track morphology deviated significantly from that of the foot. Dry sand tracks were characterized by the outward and upward movement of sediment and tracks in saturated sand by mainly downward displacement. The finer-grained saturated sand was also associated with liquefaction and closure of digit imprints. Tracks from the Middle Jurassic Cleveland Basin of Yorkshire showed features of the saturated state. The range of experimental track morphotypes formed by one foot highlighted the difficulties in assigning a print type to a particular trackmaker and the importance of excluding preservational variants from ichnotaxonomic studies.

@article{doi101080104209402010510026,
    author = "Jackson, Simon J. and Whyte, M. A. and Romano, Mike",
    title = "Range of Experimental Dinosaur (Hypsilophodon foxii) Footprints Due to Variation in Sand Consistency: How Wet Was the Track?",
    year = "2010",
    journal = "Ichnos/Ichnos : an international journal for plant and animal traces",
    abstract = "The laboratory-controlled simulations of dinosaur footprints in this study revealed characteristic track features that could be used to identify the consistency of sand substrates and provide an insight into the paleoenvironment. A model foot of Hypsilophodon foxii was indented into three sands of four different moisture (= water) contents. The two intermediate moist states were characterized by shallow tridactyl impressions, in which only digits II–IV were impressed, showing details of padding and claws. Where the foot penetrated more deeply, in the dry and saturated states, the hallux and heel were also impressed; in these cases, the foot detail was not preserved accurately and track morphology deviated significantly from that of the foot. Dry sand tracks were characterized by the outward and upward movement of sediment and tracks in saturated sand by mainly downward displacement. The finer-grained saturated sand was also associated with liquefaction and closure of digit imprints. Tracks from the Middle Jurassic Cleveland Basin of Yorkshire showed features of the saturated state. The range of experimental track morphotypes formed by one foot highlighted the difficulties in assigning a print type to a particular trackmaker and the importance of excluding preservational variants from ichnotaxonomic studies.",
    url = "https://doi.org/10.1080/10420940.2010.510026",
    doi = "10.1080/10420940.2010.510026",
    openalex = "W2007103212",
    references = "doi10108010420940109380189, doi102110palo2007p07070r, doi1023073514457"
}

Ichnology deals with the traces of prehistoric organisms and thus with the study of dinosaur footprints and tracks. This paper reports on a reliable and precise methodology developed to integrate high‐resolution close range photogrammetry and range sensors for 3D surveys of dinosaur footprints. The 3D footprint and track models recovered here yield a great deal of accurate morphological and morphometrical information, providing palaeoichnologists with a simpler and cheaper way to document track fossils and the opportunity to formulate new hypotheses about the dynamics of dinosaur locomotion.

@article{remondino20103d,
    author = "Remondino, Fabio and Rizzi, Alessandro and Girardi, Stefano and Petti, Fabio Massimo and Avanzini, Marco",
    title = "3D Ichnology—recovering digital 3D models of dinosaur footprints",
    year = "2010",
    journal = "The Photogrammetric Record",
    abstract = "Ichnology deals with the traces of prehistoric organisms and thus with the study of dinosaur footprints and tracks. This paper reports on a reliable and precise methodology developed to integrate high‐resolution close range photogrammetry and range sensors for 3D surveys of dinosaur footprints. The 3D footprint and track models recovered here yield a great deal of accurate morphological and morphometrical information, providing palaeoichnologists with a simpler and cheaper way to document track fossils and the opportunity to formulate new hypotheses about the dynamics of dinosaur locomotion.",
    url = "https://doi.org/10.1111/j.1477-9730.2010.00587.x",
    doi = "10.1111/j.1477-9730.2010.00587.x",
    number = "131",
    openalex = "W1822041865",
    pages = "266-282",
    volume = "25",
    references = "doi1010079789400904095, doi101007s1126300700891, doi101109mcg20041318815, doi101109msp2008923093, doi101111j14779730200600383x, doi10111711631921, doi101260147807709788549439, doi1023073514595, doi103929ethza005055636, openalexw53652771"
}

In 1940 R.T. Bird of the American Museum of Natural History collected segments of a sauropod and a theropod trackway from a site in the bed (Glen Rose Formation; Lower Cretaceous) of the Paluxy River, in what is now Dinosaur Valley State Park (Glen Rose, Texas, USA). However, Bird left undocumented thousands of other dinosaur footprints from this and other Paluxy tracksites. In 2008 and 2009 our international team carried out fieldwork to create detailed photomosaics of extant Paluxy tracksites, using GIS technology to combine these with historic maps and photographs. We also made photographs, tracings, LiDAR images, and measurements of individual footprints and trackways. Paluxy dinosaur tracksites occur in more than one tracklayer, but the largest and most spectacular footprints occur in the Main Tracklayer, a 20-30 cm thick, homogeneous dolomudstone that is thickly riddled with vertical invertebrate burrows (Skolithos). There are two dinosaur footprint morphotypes in the Main Tracklayer: spectacular sauropod trackways (Brontopodus) and the far more numerous tridactyl footprints, most or all of which were made by large theropods (possible ornithopod prints occur in a tracklayer stratigraphically higher than the Main Tracklayer). Tridactyl footprints are highly variable in quality; Paluxy tracksites collectively constitute a natural laboratory for investigating how trackmaker-substrate interactions create extensive extramorphological variability from a single foot morphology. Trackways of bipedal dinosaurs show a “mirror-image” distribution, suggesting movement of animals back and forth along a shoreline. In contrast, most sauropod trackways head in roughly the same direction, suggesting passage of a group of dinosaurs. The trackways collected by R.T. Bird suggest that at least one theropod was following a sauropod.

@article{openalexw1592791648,
    author = "Farlow, James O. and O’Brien, Mike and Kuban, Glenn J. and Dattilo, Benjamin F. and Bates, Karl T. and Falkingham, Peter and Piñuela, Laura and Rose, Amanda and Freels, A. and Kumagai, Cory J. and Libben, Courtney and Smith, Justin E. H. and Whitcraft, James",
    title = "Dinosaur Tracksites of the Paluxy River Valley (Glen Rose Formation, Lower Cretaceous), Dinosaur Valley State Park, Somervell County, Texas.",
    year = "2012",
    journal = "Opus: Research \& Creativity (Indiana University – Purdue University Fort Wayne)",
    abstract = "In 1940 R.T. Bird of the American Museum of Natural History collected segments of a sauropod and a theropod trackway from a site in the bed (Glen Rose Formation; Lower Cretaceous) of the Paluxy River, in what is now Dinosaur Valley State Park (Glen Rose, Texas, USA). However, Bird left undocumented thousands of other dinosaur footprints from this and other Paluxy tracksites. In 2008 and 2009 our international team carried out fieldwork to create detailed photomosaics of extant Paluxy tracksites, using GIS technology to combine these with historic maps and photographs. We also made photographs, tracings, LiDAR images, and measurements of individual footprints and trackways. Paluxy dinosaur tracksites occur in more than one tracklayer, but the largest and most spectacular footprints occur in the Main Tracklayer, a 20-30 cm thick, homogeneous dolomudstone that is thickly riddled with vertical invertebrate burrows (Skolithos). There are two dinosaur footprint morphotypes in the Main Tracklayer: spectacular sauropod trackways (Brontopodus) and the far more numerous tridactyl footprints, most or all of which were made by large theropods (possible ornithopod prints occur in a tracklayer stratigraphically higher than the Main Tracklayer). Tridactyl footprints are highly variable in quality; Paluxy tracksites collectively constitute a natural laboratory for investigating how trackmaker-substrate interactions create extensive extramorphological variability from a single foot morphology. Trackways of bipedal dinosaurs show a “mirror-image” distribution, suggesting movement of animals back and forth along a shoreline. In contrast, most sauropod trackways head in roughly the same direction, suggesting passage of a group of dinosaurs. The trackways collected by R.T. Bird suggest that at least one theropod was following a sauropod.",
    openalex = "W1592791648",
    references = "doi1010160025322767900515, doi101017s0094837300026543, doi10108002724634199810011086, doi10108010420940601006826, doi1023073514816, doi105281zenodo4664674, doi105860choice332752, hastings1987new, milne1983dinosaur, openalexw114509570, openalexw151338792, openalexw2596117615, openalexw2617990244, openalexw603337959"
}

We report a Holocene human and animal footprint site from the Namib Sand Sea, south of Walvis Bay, Namibia. Using these data, we explore intratrail footprint variability associated with small variations in substrate properties using a "whole foot" analytical technique developed for the studies in human ichnology. We demonstrate high levels of intratrail variability as a result of variations in grain size, depositional moisture content, and the degree of sediment disturbance, all of which determine the bearing capacity of the substrate. The two principal trails were examined, which had consistent stride and step lengths, and as such variations in print typology were primarily controlled by substrate rather than locomotor mechanics. Footprint typology varies with bearing capacity such that firm substrates show limited impressions associated with areas of peak plantar pressure, whereas softer substrates are associated with deep prints with narrow heels and reduced medial longitudinal arches. Substrates of medium bearing capacity give displacement rims and proximal movement of sediment, which obscures the true form of the medial longitudinal arch. A simple conceptual model is offered which summarizes these conclusions and is presented as a basis for further investigation into the control of substrate on footprint typology. The method, model, and results presented here are essential in the interpretation of any sites of greater paleoanthropological significance, such as recently reported from Ileret (1.5 Ma, Kenya; Bennett et al.: Science 323 (2009) 1197-1201).

@article{doi101002ajpa22276,
    author = "Morse, Sarita A. and Bennett, Matthew R. and Liutkus-Pierce, Cynthia M. and Thackeray, Francis and McClymont, Juliet and Savage, Russell and Crompton, Robin H.",
    title = "Holocene footprints in Namibia: The influence of substrate on footprint variability",
    year = "2013",
    journal = "American Journal of Physical Anthropology",
    abstract = {We report a Holocene human and animal footprint site from the Namib Sand Sea, south of Walvis Bay, Namibia. Using these data, we explore intratrail footprint variability associated with small variations in substrate properties using a "whole foot" analytical technique developed for the studies in human ichnology. We demonstrate high levels of intratrail variability as a result of variations in grain size, depositional moisture content, and the degree of sediment disturbance, all of which determine the bearing capacity of the substrate. The two principal trails were examined, which had consistent stride and step lengths, and as such variations in print typology were primarily controlled by substrate rather than locomotor mechanics. Footprint typology varies with bearing capacity such that firm substrates show limited impressions associated with areas of peak plantar pressure, whereas softer substrates are associated with deep prints with narrow heels and reduced medial longitudinal arches. Substrates of medium bearing capacity give displacement rims and proximal movement of sediment, which obscures the true form of the medial longitudinal arch. A simple conceptual model is offered which summarizes these conclusions and is presented as a basis for further investigation into the control of substrate on footprint typology. The method, model, and results presented here are essential in the interpretation of any sites of greater paleoanthropological significance, such as recently reported from Ileret (1.5 Ma, Kenya; Bennett et al.: Science 323 (2009) 1197-1201).},
    url = "https://doi.org/10.1002/ajpa.22276",
    doi = "10.1002/ajpa.22276",
    openalex = "W1545429486",
    references = "doi1010079789401096836, doi10100797894011964063, doi10103820167, doi101038278317a0, doi10108010420940802471027, doi101098rsif20110258, doi101098rstb19970035, doi101126science1168132, doi101371journalpone0009769, doi102110palo2007p07070r, doi1023072803270, doi1023073514964"
}

Locomotion over deformable substrates is a common occurrence in nature. Footprints represent sedimentary distortions that provide anatomical, functional, and behavioral insights into trackmaker biology. The interpretation of such evidence can be challenging, however, particularly for fossil tracks recovered at bedding planes below the originally exposed surface. Even in living animals, the complex dynamics that give rise to footprint morphology are obscured by both foot and sediment opacity, which conceals animal-substrate and substrate-substrate interactions. We used X-ray reconstruction of moving morphology (XROMM) to image and animate the hind limb skeleton of a chicken-like bird traversing a dry, granular material. Foot movement differed significantly from walking on solid ground; the longest toe penetrated to a depth of ∼5 cm, reaching an angle of 30° below horizontal before slipping backward on withdrawal. The 3D kinematic data were integrated into a validated substrate simulation using the discrete element method (DEM) to create a quantitative model of limb-induced substrate deformation. Simulation revealed that despite sediment collapse yielding poor quality tracks at the air-substrate interface, subsurface displacements maintain a high level of organization owing to grain-grain support. Splitting the substrate volume along "virtual bedding planes" exposed prints that more closely resembled the foot and could easily be mistaken for shallow tracks. DEM data elucidate how highly localized deformations associated with foot entry and exit generate specific features in the final tracks, a temporal sequence that we term "track ontogeny." This combination of methodologies fosters a synthesis between the surface/layer-based perspective prevalent in paleontology and the particle/volume-based perspective essential for a mechanistic understanding of sediment redistribution during track formation.

@article{doi101073pnas1416252111,
    author = "Falkingham, Peter and Gatesy, Stephen M.",
    title = "The birth of a dinosaur footprint: Subsurface 3D motion reconstruction and discrete element simulation reveal track ontogeny",
    year = "2014",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = {Locomotion over deformable substrates is a common occurrence in nature. Footprints represent sedimentary distortions that provide anatomical, functional, and behavioral insights into trackmaker biology. The interpretation of such evidence can be challenging, however, particularly for fossil tracks recovered at bedding planes below the originally exposed surface. Even in living animals, the complex dynamics that give rise to footprint morphology are obscured by both foot and sediment opacity, which conceals animal-substrate and substrate-substrate interactions. We used X-ray reconstruction of moving morphology (XROMM) to image and animate the hind limb skeleton of a chicken-like bird traversing a dry, granular material. Foot movement differed significantly from walking on solid ground; the longest toe penetrated to a depth of ∼5 cm, reaching an angle of 30° below horizontal before slipping backward on withdrawal. The 3D kinematic data were integrated into a validated substrate simulation using the discrete element method (DEM) to create a quantitative model of limb-induced substrate deformation. Simulation revealed that despite sediment collapse yielding poor quality tracks at the air-substrate interface, subsurface displacements maintain a high level of organization owing to grain-grain support. Splitting the substrate volume along "virtual bedding planes" exposed prints that more closely resembled the foot and could easily be mistaken for shallow tracks. DEM data elucidate how highly localized deformations associated with foot entry and exit generate specific features in the final tracks, a temporal sequence that we term "track ontogeny." This combination of methodologies fosters a synthesis between the surface/layer-based perspective prevalent in paleontology and the particle/volume-based perspective essential for a mechanistic understanding of sediment redistribution during track formation.},
    url = "https://doi.org/10.1073/pnas.1416252111",
    doi = "10.1073/pnas.1416252111",
    openalex = "W1964452431",
    references = "doi101002jez589, doi1010079789400904095, doi101016s0031018296001423, doi10103820167, doi10108809650393181015012, doi101111j14691795200600044x, doi101111jzo12110, doi101126science1229163, doi101144gslsp20042280106, doi101504pcfd2012047457, doi1023071445147, doi1023072412825, doi1023073514816, lockley1988james, openalexw1592791648, openalexw2506868775"
}

It is inevitable that some important specimens will become lost or damaged over time, conservation is therefore of vital importance. The Paluxy River dinosaur tracksite is among the most famous in the world. In 1940, Roland T. Bird described and excavated a portion of the site containing associated theropod and sauropod trackways. This excavated trackway was split up and housed in different institutions, and during the process a portion was lost or destroyed. We applied photogrammetric techniques to photographs taken by Bird over 70 years ago, before the trackway was removed, to digitally reconstruct the site as it was prior to excavation. The 3D digital model offers the opportunity to corroborate maps drawn by R.T. Bird when the tracksite was first described. More broadly, this work demonstrates the exciting potential for digitally recreating palaeontological, geological, or archaeological specimens that have been lost to science, but for which photographic documentation exists.

@article{doi101371journalpone0093247,
    author = "Falkingham, Peter and Bates, Karl T. and Farlow, James O.",
    title = "Historical Photogrammetry: Bird's Paluxy River Dinosaur Chase Sequence Digitally Reconstructed as It Was prior to Excavation 70 Years Ago",
    year = "2014",
    journal = "PLoS ONE",
    abstract = "It is inevitable that some important specimens will become lost or damaged over time, conservation is therefore of vital importance. The Paluxy River dinosaur tracksite is among the most famous in the world. In 1940, Roland T. Bird described and excavated a portion of the site containing associated theropod and sauropod trackways. This excavated trackway was split up and housed in different institutions, and during the process a portion was lost or destroyed. We applied photogrammetric techniques to photographs taken by Bird over 70 years ago, before the trackway was removed, to digitally reconstruct the site as it was prior to excavation. The 3D digital model offers the opportunity to corroborate maps drawn by R.T. Bird when the tracksite was first described. More broadly, this work demonstrates the exciting potential for digitally recreating palaeontological, geological, or archaeological specimens that have been lost to science, but for which photographic documentation exists.",
    url = "https://doi.org/10.1371/journal.pone.0093247",
    doi = "10.1371/journal.pone.0093247",
    openalex = "W2095708090",
    references = "openalexw1592791648"
}

An ichnological and sedimentological study of the El Frontal dinosaur tracksite (Early Cretaceous, Cameros basin, Soria, Spain) highlights the pronounced intra-trackway variation found in track morphologies of four theropod trackways. Photogrammetric 3D digital models revealed various and distinct intra-trackway morphotypes, which reflect changes in footprint parameters such as the pace length, the track length, depth, and height of displacement rims. Sedimentological analyses suggest that the original substrate was non-homogenous due to lateral changes in adjoining microfacies. Multidata analyses indicate that morphological differences in these deep and shallow tracks represent a part of a continuum of track morphologies and geometries produced by a gradient of substrate consistencies across the site. This implies that the large range of track morphologies at this site resulted from similar trackmakers crossing variable facies. The trackways at the El Frontal site present an exemplary case of how track morphology, and consequently potential ichnotaxa, can vary, even when produced by a single trackmaker.

@article{doi101371journalpone0093708,
    author = "Razzolini, Novella L. and Vila, Bernat and Castanera, Diego and Falkingham, Peter and Barco, José Luis and Canudo, José Ignacio and Manning, Phillip L. and Galobart, Àngel",
    title = "Intra-Trackway Morphological Variations Due to Substrate Consistency: The El Frontal Dinosaur Tracksite (Lower Cretaceous, Spain)",
    year = "2014",
    journal = "PLoS ONE",
    abstract = "An ichnological and sedimentological study of the El Frontal dinosaur tracksite (Early Cretaceous, Cameros basin, Soria, Spain) highlights the pronounced intra-trackway variation found in track morphologies of four theropod trackways. Photogrammetric 3D digital models revealed various and distinct intra-trackway morphotypes, which reflect changes in footprint parameters such as the pace length, the track length, depth, and height of displacement rims. Sedimentological analyses suggest that the original substrate was non-homogenous due to lateral changes in adjoining microfacies. Multidata analyses indicate that morphological differences in these deep and shallow tracks represent a part of a continuum of track morphologies and geometries produced by a gradient of substrate consistencies across the site. This implies that the large range of track morphologies at this site resulted from similar trackmakers crossing variable facies. The trackways at the El Frontal site present an exemplary case of how track morphology, and consequently potential ichnotaxa, can vary, even when produced by a single trackmaker.",
    url = "https://doi.org/10.1371/journal.pone.0093708",
    doi = "10.1371/journal.pone.0093708",
    openalex = "W2050956423",
    references = "doi101002ajpa22276, doi101111jzo12110, openalexw2149387945"
}

Here we describe dinosaur tracks from the Langenberg Quarry near Goslar (Lower Saxony) that represent the first footprints from the Late Jurassic of Germany discovered outside the Wiehen Mountains. The footprints are preserved in Kimmeridgian marginal marine carbonates. They vary in length from 36 to 47 cm and were made by theropod dinosaurs. The original tracksite with 20 footprints was destroyed by quarrying soon after its discovery in 2003. Only the five best defined footprints were excavated. Based on scanned-in analog photographs which were taken during the excavation, a three-dimensional (3-D) model of the original tracksite was generated by applying historical photogrammetry. The resulting model is accurate enough to allow a detailed description of the original tracksite. Different preservation types result from changing substrate properties and include both well-defined footprints and deeply impressed footprints with elongated heel and variably defined digit impressions. The tracksite was discovered stratigraphically close to the bone accumulation of the dwarfed sauropod dinosaur Europasaurus holgeri and probably records a sea level fall along with a faunal interchange, which would likely have eliminated the resident dwarf island fauna. The two largest and best preserved footprints differ from most other Late Jurassic theropod footprints in their great width. Two different trackmaker species might have been present at the site. Several hypotheses presented in a recent paper on Late Jurassic dinosaur tracks from the Wiehen Mountains by Diedrich (2011b) are commented upon herein.

@article{doi1026879529,
    author = "Lallensack, Jens N. and Sander, M and Knötschke, Nils and Wings, Oliver",
    title = "Dinosaur tracks from the Langenberg Quarry (Late Jurassic, Germany) reconstructed with historical photogrammetry: Evidence for large theropods soon after insular dwarfism",
    year = "2015",
    journal = "Palaeontologia Electronica",
    abstract = "Here we describe dinosaur tracks from the Langenberg Quarry near Goslar (Lower Saxony) that represent the first footprints from the Late Jurassic of Germany discovered outside the Wiehen Mountains. The footprints are preserved in Kimmeridgian marginal marine carbonates. They vary in length from 36 to 47 cm and were made by theropod dinosaurs. The original tracksite with 20 footprints was destroyed by quarrying soon after its discovery in 2003. Only the five best defined footprints were excavated. Based on scanned-in analog photographs which were taken during the excavation, a three-dimensional (3-D) model of the original tracksite was generated by applying historical photogrammetry. The resulting model is accurate enough to allow a detailed description of the original tracksite. Different preservation types result from changing substrate properties and include both well-defined footprints and deeply impressed footprints with elongated heel and variably defined digit impressions. The tracksite was discovered stratigraphically close to the bone accumulation of the dwarfed sauropod dinosaur Europasaurus holgeri and probably records a sea level fall along with a faunal interchange, which would likely have eliminated the resident dwarf island fauna. The two largest and best preserved footprints differ from most other Late Jurassic theropod footprints in their great width. Two different trackmaker species might have been present at the site. Several hypotheses presented in a recent paper on Late Jurassic dinosaur tracks from the Wiehen Mountains by Diedrich (2011b) are commented upon herein.",
    url = "https://doi.org/10.26879/529",
    doi = "10.26879/529",
    openalex = "W1903208034",
    references = "doi10103820167, doi101038261129a0, doi101073pnas1416252111, doi10108010420940802471027, doi101111j10963642201000620x, doi101111jzo12110, doi101525california97805202462320010001, doi102110pec98020003, doi1026879264, doi105860choice273305, doi105860choice435907, martinsander2006bone, openalexw114509570, openalexw2593733766"
}

We documented trackways of free-living Crocodylus acutus on beaches at the mouths of Tamarindo and Ventanas estuaries, Costa Rica. Our crocodiles had estimated total lengths of 1–3 meters or more. Manus prints have five digits, with digits I–III bearing claw marks. Pes prints have four digits, with claw marks on digits I–III. The pes is plantigrade. Claws generally dig into the substrate. Apart from claw marks, digit I and the heel of the pes are usually the most deeply impressed parts of footprints. Trackways are wide-gauge. Pes prints are usually positioned just behind ipsilateral manus prints of the same set and may overlap them. Manus and pes prints angle slightly outward with respect to the crocodile's direction of movement. Claw-bearing digits of both the manus and pes may create curved, concave-toward-the-midline drag marks as the autopodium is protracted. The tail mark varies in depth and clarity, and in shape from nearly linear to markedly sinuous. Sometimes the tail mark hugs the trackway midline, but sometimes it is closer to, or even cuts across, prints of one side. American crocodile footprints and trackways are similar to those observed in other extant crocodylian species, indicating substantial trackway conservatism across the group.

@article{doi1010801042094020171350856,
    author = "Farlow, James O. and Robinson, Nathan J. and Kumagai, Cory J. and Paladino, Frank V. and Falkingham, Peter and Elsey, Ruth M. and Martin, Anthony J.",
    title = "Trackways of the American Crocodile (Crocodylus acutus) in Northwestern Costa Rica: Implications for Crocodylian Ichnology",
    year = "2017",
    journal = "Ichnos/Ichnos : an international journal for plant and animal traces",
    abstract = "We documented trackways of free-living Crocodylus acutus on beaches at the mouths of Tamarindo and Ventanas estuaries, Costa Rica. Our crocodiles had estimated total lengths of 1–3 meters or more. Manus prints have five digits, with digits I–III bearing claw marks. Pes prints have four digits, with claw marks on digits I–III. The pes is plantigrade. Claws generally dig into the substrate. Apart from claw marks, digit I and the heel of the pes are usually the most deeply impressed parts of footprints. Trackways are wide-gauge. Pes prints are usually positioned just behind ipsilateral manus prints of the same set and may overlap them. Manus and pes prints angle slightly outward with respect to the crocodile's direction of movement. Claw-bearing digits of both the manus and pes may create curved, concave-toward-the-midline drag marks as the autopodium is protracted. The tail mark varies in depth and clarity, and in shape from nearly linear to markedly sinuous. Sometimes the tail mark hugs the trackway midline, but sometimes it is closer to, or even cuts across, prints of one side. American crocodile footprints and trackways are similar to those observed in other extant crocodylian species, indicating substantial trackway conservatism across the group.",
    url = "https://doi.org/10.1080/10420940.2017.1350856",
    doi = "10.1080/10420940.2017.1350856",
    openalex = "W2740130720",
    references = "doi101016s001669958880038x, doi1010719781486300679, doi101086273307, doi101111j109636421961tb00220x, doi101111j146979981975tb01405x, doi1026879264, openalexw114509570, openalexw149861632, openalexw2619609965, openalexw599469367"
}

A new ichnospecies of a large theropod dinosaur, Megalosauripus transjuranicus, is described from the Reuchenette Formation (Early-Late Kimmeridgian, Late Jurassic) of NW Switzerland. It is based on very well-preserved and morphologically-distinct tracks (impressions) and several trackways, including different preservational types from different tracksites and horizons. All trackways were excavated along federal Highway A16 near Courtedoux (Canton Jura) and systematically documented in the field including orthophotos and laserscans. The best-preserved tracks were recovered and additional tracks were casted. Megalosauripus transjuranicus is characterized by tridactyl tracks with clear claw and digital pad impressions, and notably an exceptionally large and round first phalangeal pad on the fourth digit (PIV1) that is connected to digit IV and forms the round heel area. Due to this combination of features, M. transjuranicus clearly is of theropod (and not ornithopod) origin. M. transjuranicus is compared to other Megalosauripus tracks and similar ichnotaxa and other unassigned tracks from the Early Jurassic to Early Cretaceous. It is clearly different from other ichnogenera assigned to large theropods such as Eubrontes-Grallator from the Late Triassic and Early Jurassic or Megalosauripus-Megalosauropus-Bueckeburgichnus and Therangospodus tracks from the Late Jurassic and Early Cretaceous. A second tridactyl morphotype (called Morphotype II) is different from Megalosauripus transjuranicus in being subsymmetric, longer than wide (sometimes almost as wide as long), with blunt toe impressions and no evidence for discrete phalangeal pad and claw marks. Some Morphotype II tracks are found in trackways that are assigned to M. transjuranicus, to M.? transjuranicus or M. cf. transjuranicus indicating that some Morphotype II tracks are intra-trackway preservational variants of a morphological continuum of Megalosauripus transjuranicus. On the other hand, several up to 40 steps long trackways very consistently present Morphotype II features (notably blunt digits) and do not exhibit any of the features that are typical for Megalosauripus (notably phalangeal pads). Therefore, it is not very likely that these tracks are preservational variants of Megalosauripus transjuranicus or Megalosauripus isp. These trackways are interpreted to have been left by an ornithopod dinosaur. The high frequency of large theropod tracks in tidal-flat deposits of the Jura carbonate platform, associated on single ichnoassemblages with minute to medium-sized tridactyl and tiny to large sauropod tracks has important implications for the dinosaur community and for paleoenvironmental and paleogeographical reconstructions. As with most other known occurrences of Megalosauripus tracks, M. transjuranicus is found in coastal settings, which may reflect the preference of their theropod trackmakers for expanded carbonate flats where food was abundant.

@article{doi101371journalpone0180289,
    author = "Razzolini, Novella L. and Belvedere, Matteo and Marty, Daniel and Paratte, Géraldine and Lovis, Christel and Cattin, Marielle and Meyer, Christian A.",
    title = "Megalosauripus transjuranicus ichnosp. nov. A new Late Jurassic theropod ichnotaxon from NW Switzerland and implications for tridactyl dinosaur ichnology and ichnotaxomy",
    year = "2017",
    journal = "PLoS ONE",
    abstract = "A new ichnospecies of a large theropod dinosaur, Megalosauripus transjuranicus, is described from the Reuchenette Formation (Early-Late Kimmeridgian, Late Jurassic) of NW Switzerland. It is based on very well-preserved and morphologically-distinct tracks (impressions) and several trackways, including different preservational types from different tracksites and horizons. All trackways were excavated along federal Highway A16 near Courtedoux (Canton Jura) and systematically documented in the field including orthophotos and laserscans. The best-preserved tracks were recovered and additional tracks were casted. Megalosauripus transjuranicus is characterized by tridactyl tracks with clear claw and digital pad impressions, and notably an exceptionally large and round first phalangeal pad on the fourth digit (PIV1) that is connected to digit IV and forms the round heel area. Due to this combination of features, M. transjuranicus clearly is of theropod (and not ornithopod) origin. M. transjuranicus is compared to other Megalosauripus tracks and similar ichnotaxa and other unassigned tracks from the Early Jurassic to Early Cretaceous. It is clearly different from other ichnogenera assigned to large theropods such as Eubrontes-Grallator from the Late Triassic and Early Jurassic or Megalosauripus-Megalosauropus-Bueckeburgichnus and Therangospodus tracks from the Late Jurassic and Early Cretaceous. A second tridactyl morphotype (called Morphotype II) is different from Megalosauripus transjuranicus in being subsymmetric, longer than wide (sometimes almost as wide as long), with blunt toe impressions and no evidence for discrete phalangeal pad and claw marks. Some Morphotype II tracks are found in trackways that are assigned to M. transjuranicus, to M.? transjuranicus or M. cf. transjuranicus indicating that some Morphotype II tracks are intra-trackway preservational variants of a morphological continuum of Megalosauripus transjuranicus. On the other hand, several up to 40 steps long trackways very consistently present Morphotype II features (notably blunt digits) and do not exhibit any of the features that are typical for Megalosauripus (notably phalangeal pads). Therefore, it is not very likely that these tracks are preservational variants of Megalosauripus transjuranicus or Megalosauripus isp. These trackways are interpreted to have been left by an ornithopod dinosaur. The high frequency of large theropod tracks in tidal-flat deposits of the Jura carbonate platform, associated on single ichnoassemblages with minute to medium-sized tridactyl and tiny to large sauropod tracks has important implications for the dinosaur community and for paleoenvironmental and paleogeographical reconstructions. As with most other known occurrences of Megalosauripus tracks, M. transjuranicus is found in coastal settings, which may reflect the preference of their theropod trackmakers for expanded carbonate flats where food was abundant.",
    url = "https://doi.org/10.1371/journal.pone.0180289",
    doi = "10.1371/journal.pone.0180289",
    openalex = "W2735513027",
    references = "crossref1976allosaurus, doi1010079789400904095, doi101016s0012821x0100588x, doi101016s001669958880038x, doi101017cbo9780511628948, doi101038261129a0, doi101038srep31494, doi10108000241160600787890, doi10108008912960903503345, doi101080147720192011630927, doi101306m43478, doi101371journalpone0103613, doi1026879529, doi105860choice273305, doi107717peerj2059, fiorillo2014herd, mateus2010a, nouri2011tetradactyl"
}

Predator-prey interactions revealed by vertebrate trace fossils are extremely rare. We present footprint evidence from White Sands National Monument in New Mexico for the association of sloth and human trackways. Geologically, the sloth and human trackways were made contemporaneously, and the sloth trackways show evidence of evasion and defensive behavior when associated with human tracks. Behavioral inferences from these trackways indicate prey selection and suggest that humans were harassing, stalking, and/or hunting the now-extinct giant ground sloth in the terminal Pleistocene.

@article{doi101126sciadvaar7621,
    author = "Bustos, David and Jakeway, Jackson and Urban, Tommy and Holliday, Vance T. and Fenerty, Brendan and Raichlen, David A. and Budka, Marcin and Reynolds, Sally C. and Allen, Bruce D. and Love, David W. and Santucci, Vincent and Odess, Daniel and Willey, P. and McDonald, H. Gregory and Bennett, Matthew R.",
    title = "Footprints preserve terminal Pleistocene hunt? Human-sloth interactions in North America",
    year = "2018",
    journal = "Science Advances",
    abstract = "Predator-prey interactions revealed by vertebrate trace fossils are extremely rare. We present footprint evidence from White Sands National Monument in New Mexico for the association of sloth and human trackways. Geologically, the sloth and human trackways were made contemporaneously, and the sloth trackways show evidence of evasion and defensive behavior when associated with human tracks. Behavioral inferences from these trackways indicate prey selection and suggest that humans were harassing, stalking, and/or hunting the now-extinct giant ground sloth in the terminal Pleistocene.",
    url = "https://doi.org/10.1126/sciadv.aar7621",
    doi = "10.1126/sciadv.aar7621",
    openalex = "W2802582932",
    references = "doi101002ajpa22276, doi1010079783319085722, doi101016jjaa201607012, doi101016jjtbi200403016, doi101016jsedgeo200610006, doi101073pnas0502777102, doi101073pnas0800560105, doi10108010420940802471027, doi101098rstb19910113, doi101126science1137166, openalexw2183707334"
}

BACKGROUND:) and an ornithopod-like morphotype (Morphotype II) have recently been described at these sites. METHODS: The quality of morphological preservation (preservation grade), the depth of the footprint, the shape variation, and the footprint proportions (FL/footprint width (FW) ratio and mesaxony) along the trackways have been analyzed using 3D models and false-color depth maps in order to determine the exact number of small to medium-sized morphotypes present in the tracksites. RESULTS: = 93) recovered during the excavations has made it possible to identify and characterize the two morphotypes distinguished in the field. The gracile morphotype is mainly characterized by a high FL/FW ratio, high mesaxony, low divarication angles and clear, sharp claw marks, and phalangeal pads (2-3-4). By contrast, the robust morphotype is characterized by a lower FL/FW ratio, weaker mesaxony, slightly higher divarication angles and clear, sharp claw marks (when preserved), whereas the phalangeal pads are not clearly preserved although they might be present. DISCUSSION:. This work sheds new light on combining an analysis of variations in footprint morphology through 3D models and false-color depth maps, with the study of possible ontogenetic variations and the identification of small-sized tridactyl ichnotaxa for the description of new dinosaur tracks.

@article{doi107717peerj4579,
    author = "Castanera, Diego and Belvedere, Matteo and Marty, Daniel and Paratte, Géraldine and Lapaire-Cattin, Marielle and Lovis, Christel and Meyer, Christian A.",
    title = "A walk in the maze: variation in Late Jurassic tridactyl dinosaur tracks from the Swiss Jura Mountains (NW Switzerland)",
    year = "2018",
    journal = "PeerJ",
    abstract = "BACKGROUND:) and an ornithopod-like morphotype (Morphotype II) have recently been described at these sites. METHODS: The quality of morphological preservation (preservation grade), the depth of the footprint, the shape variation, and the footprint proportions (FL/footprint width (FW) ratio and mesaxony) along the trackways have been analyzed using 3D models and false-color depth maps in order to determine the exact number of small to medium-sized morphotypes present in the tracksites. RESULTS: = 93) recovered during the excavations has made it possible to identify and characterize the two morphotypes distinguished in the field. The gracile morphotype is mainly characterized by a high FL/FW ratio, high mesaxony, low divarication angles and clear, sharp claw marks, and phalangeal pads (2-3-4). By contrast, the robust morphotype is characterized by a lower FL/FW ratio, weaker mesaxony, slightly higher divarication angles and clear, sharp claw marks (when preserved), whereas the phalangeal pads are not clearly preserved although they might be present. DISCUSSION:. This work sheds new light on combining an analysis of variations in footprint morphology through 3D models and false-color depth maps, with the study of possible ontogenetic variations and the identification of small-sized tridactyl ichnotaxa for the description of new dinosaur tracks.",
    url = "https://doi.org/10.7717/peerj.4579",
    doi = "10.7717/peerj.4579",
    openalex = "W2795960480",
    references = "doi101371journalpone0180289, doi107717peerj2059"
}

Abstract The functional anatomy of the hindlimb of bipedal dinosaurs has been intensively studied. Yet, surprisingly little work has been done concerning functional adaptation of digits for terrestrial locomotion. While complete and articulated pes skeletons are scarce, pes shape is abundantly recorded by fossil footprints. We elucidate the significance of footprint shape and size for locomotion using a large sample (n = 303) of tridactyl dinosaur footprints from a broad range of geographical localities and time slots. Size and shape variation are characterized separately for theropods and ornithischians, the two principal trackmaker taxa. At smaller sizes, theropod footprints are best discriminated from ornithischian footprints by their smaller interdigital angle and larger projection of digit III; at larger sizes digital widths are effective discriminants. Ornithischian footprints increase in size from the Early Jurassic to the Late Cretaceous, a trend not observed in theropod footprints. Size and function are argued to be important determinants of footprint shape, and an attempt made to infer function from shape. Digit III projection and length‐to‐width ratio of the footprints are negatively correlated with size in both groups; digit impression width is positively correlated with size only in ornithischians. Digit III projection appears to be positively correlated with cursorial ability. Increased interdigital angles are associated with a decrease in digital width, possibly an adaptation for stability. Weak digit III projection and increased digital width are interpreted as adaptations for graviportality. Footprints yield great potential for the understanding of the functional morphology of dinosaur feet.

@article{doi101111pala12449,
    author = "Lallensack, Jens N. and Engler, Thomas and Barthel, H. Jonas",
    title = "Shape variability in tridactyl dinosaur footprints: the significance of size and function",
    year = "2019",
    journal = "Palaeontology",
    abstract = "Abstract The functional anatomy of the hindlimb of bipedal dinosaurs has been intensively studied. Yet, surprisingly little work has been done concerning functional adaptation of digits for terrestrial locomotion. While complete and articulated pes skeletons are scarce, pes shape is abundantly recorded by fossil footprints. We elucidate the significance of footprint shape and size for locomotion using a large sample (n = 303) of tridactyl dinosaur footprints from a broad range of geographical localities and time slots. Size and shape variation are characterized separately for theropods and ornithischians, the two principal trackmaker taxa. At smaller sizes, theropod footprints are best discriminated from ornithischian footprints by their smaller interdigital angle and larger projection of digit III; at larger sizes digital widths are effective discriminants. Ornithischian footprints increase in size from the Early Jurassic to the Late Cretaceous, a trend not observed in theropod footprints. Size and function are argued to be important determinants of footprint shape, and an attempt made to infer function from shape. Digit III projection and length‐to‐width ratio of the footprints are negatively correlated with size in both groups; digit impression width is positively correlated with size only in ornithischians. Digit III projection appears to be positively correlated with cursorial ability. Increased interdigital angles are associated with a decrease in digital width, possibly an adaptation for stability. Weak digit III projection and increased digital width are interpreted as adaptations for graviportality. Footprints yield great potential for the understanding of the functional morphology of dinosaur feet.",
    url = "https://doi.org/10.1111/pala.12449",
    doi = "10.1111/pala.12449",
    openalex = "W2982682926",
    references = "doi1010079780387217062, doi1010079789400904095, doi101016s001669958880038x, doi101111j17550998201002924x, doi101111j2041210x201100153x, doi101214ss1177013696, doi101371journalpone0180289, doi10297960650, doi105281zenodo16171435, doi105860choice273305, openalexw110315216, openalexw2942509238, sereno2017early"
}

Starting with his first report on fossil footprints from the Connecticut Valley over 180 years ago, Edward Hitchcock described what he interpreted as a burgeoning ancient fauna founded on ever-increasing nominal track diversity. For three decades, Hitchcock made countless contributions to ichnology, but his inference of thin-toed animals (Leptodactyli) from thin-toed tracks is flawed by modern criteria. Leptodactylous tracks are now recognized as variants made by thick-toed feet penetrating into soft, collapsing substrates. Herein, we take a closer look at the creation of such penetrative tracks using computer simulations of particle flow. Classic specimens are used to demonstrate how different modes of surface presentation make penetrative tracks challenging to recognize and interpret. Evaluation of 266 specimens from 43 leptodactylous ichnotaxa reveals that ∼90% are penetrative. We propose that a reliance on a single formation mechanism confounded Hitchcock’s ability to reliably recognize different trackmakers. This is not an old problem applicable only to fossils collected long ago; domination of a transmission-based model continues to bias the field today. Most texts and many publications either omit collapsed penetrative tracks or fail to recognize them as a significant source of variation. Without proper regard for subsurface toe movement and sediment flow, inferences of foot shape from track shape can, as for Hitchcock, be led far astray. The misidentification and misunderstanding of penetrative tracks impact our conception of the diversity of life in the Early Jurassic, as well as in other ichnofaunas worldwide.

@article{doi1010800272463420201781142,
    author = "Gatesy, Stephen M. and Falkingham, Peter",
    title = "Hitchcock’s Leptodactyli, Penetrative Tracks, and Dinosaur Footprint Diversity",
    year = "2020",
    journal = "Journal of Vertebrate Paleontology",
    abstract = "Starting with his first report on fossil footprints from the Connecticut Valley over 180 years ago, Edward Hitchcock described what he interpreted as a burgeoning ancient fauna founded on ever-increasing nominal track diversity. For three decades, Hitchcock made countless contributions to ichnology, but his inference of thin-toed animals (Leptodactyli) from thin-toed tracks is flawed by modern criteria. Leptodactylous tracks are now recognized as variants made by thick-toed feet penetrating into soft, collapsing substrates. Herein, we take a closer look at the creation of such penetrative tracks using computer simulations of particle flow. Classic specimens are used to demonstrate how different modes of surface presentation make penetrative tracks challenging to recognize and interpret. Evaluation of 266 specimens from 43 leptodactylous ichnotaxa reveals that ∼90\% are penetrative. We propose that a reliance on a single formation mechanism confounded Hitchcock’s ability to reliably recognize different trackmakers. This is not an old problem applicable only to fossils collected long ago; domination of a transmission-based model continues to bias the field today. Most texts and many publications either omit collapsed penetrative tracks or fail to recognize them as a significant source of variation. Without proper regard for subsurface toe movement and sediment flow, inferences of foot shape from track shape can, as for Hitchcock, be led far astray. The misidentification and misunderstanding of penetrative tracks impact our conception of the diversity of life in the Early Jurassic, as well as in other ichnofaunas worldwide.",
    url = "https://doi.org/10.1080/02724634.2020.1781142",
    doi = "10.1080/02724634.2020.1781142",
    openalex = "W3092060719",
    references = "doi101007978331946487931, doi1010079783540472261, doi1010079789400904095, doi101016s001669958880038x, doi101073pnas1416252111, doi1010800272463420171314298, doi10108809650393181015012, doi101109cvpr2016445, doi101111pala12373, doi101504pcfd2012047457, doi102110palo2007p07070r, doi10230725058147, doi1023073514816, doi1026879529, doi10297960650, doi105962bhltitle20094, doi105962bhltitle70405, lull1915triassic, openalexw1592791648, openalexw2619609965, openalexw384818744, openalexw603337959"
}

In recent years photogrammetry has become an essential tool in the study of tetrapod footprints. Morphological analyses of footprints are interpretative, thus researchers should use as much information as possible in order to eventually provide an objective conclusion. In this regard, photogrammetry is an extremely helpful tool to avoid potential biases and to better present ichnological data. We review the use of this technique in several Permian and Triassic tetrapod ichnological studies, with considerations on: (1) ichnotaxonomy, (2) track-trackmaker correlation, (3) locomotion and/or behavior, (4) substrate induced effects and (5) preservation of the fossil record and heritage. Furthermore, based on the available three-dimensional (3D) data on Permian and Triassic material, we present a first qualitative interpretation of relative depth patterns and the related functional prevalence (most deeply impressed area) within footprints. We identified three main groups: (1) anamniote, captorhinomorph/parareptile tracks (medial-median functional prevalence), (2) diapsid tracks (median functional prevalence), and (3) synapsid tracks (median-lateral functional prevalence). The use of 3D photogrammetric models brings new light on the tetrapod footprint record, helping to better understand tetrapod communities throughout the late Paleozoic (and the end-Guadalupian and end-Permian extinctions) and the tetrapod recovery during the early Mesozoic.

@article{doi103389feart202000248,
    author = "Mujal, Eudald and Marchetti, Lorenzo and Schoch, Rainer R. and Fortuny, Josep",
    title = "Upper Paleozoic to Lower Mesozoic Tetrapod Ichnology Revisited: Photogrammetry and Relative Depth Pattern Inferences on Functional Prevalence of Autopodia",
    year = "2020",
    journal = "Frontiers in Earth Science",
    abstract = "In recent years photogrammetry has become an essential tool in the study of tetrapod footprints. Morphological analyses of footprints are interpretative, thus researchers should use as much information as possible in order to eventually provide an objective conclusion. In this regard, photogrammetry is an extremely helpful tool to avoid potential biases and to better present ichnological data. We review the use of this technique in several Permian and Triassic tetrapod ichnological studies, with considerations on: (1) ichnotaxonomy, (2) track-trackmaker correlation, (3) locomotion and/or behavior, (4) substrate induced effects and (5) preservation of the fossil record and heritage. Furthermore, based on the available three-dimensional (3D) data on Permian and Triassic material, we present a first qualitative interpretation of relative depth patterns and the related functional prevalence (most deeply impressed area) within footprints. We identified three main groups: (1) anamniote, captorhinomorph/parareptile tracks (medial-median functional prevalence), (2) diapsid tracks (median functional prevalence), and (3) synapsid tracks (median-lateral functional prevalence). The use of 3D photogrammetric models brings new light on the tetrapod footprint record, helping to better understand tetrapod communities throughout the late Paleozoic (and the end-Guadalupian and end-Permian extinctions) and the tetrapod recovery during the early Mesozoic.",
    url = "https://doi.org/10.3389/feart.2020.00248",
    doi = "10.3389/feart.2020.00248",
    openalex = "W3045211156",
    references = "doi101016jearscirev201904008, doi101016jpalaeo201401002, doi10103820167, doi101038s4155901910473, doi10108000241160600787890, doi10108010420940802471027, doi101111pala12373, doi1026879264, openalexw1496509561, openalexw2593733766"
}

Abstract The dinosaur track record features numerous examples of trackways with elongated metatarsal marks. Such ‘elongate tracks’ are often highly variable and characterized by indistinct outlines and abbreviated or missing digit impressions. Elongate dinosaur tracks are well‐known from the Paluxy River bed of Texas, where some have been interpreted as ‘man tracks’ by creationists due to their superficially human‐like appearance. The horizontal orientation of the metatarsal marks led to the now widely accepted idea of a facultative plantigrade, or ‘flat‐footed’, mode of locomotion in a variety of dinosaurian trackmakers small to large. This hypothesis, however, is at odds with the observation that elongate tracks do not indicate reduced locomotion speeds and increased pace angulation values, but instead are correlated with low anatomical fidelity. We here interpret elongate tracks as deep penetrations of the foot in soft sediment. Sediment may collapse above parts of the descending foot, leaving a shallow surface track that preserves a metatarsal mark. The length of a metatarsal mark is determined by multiple factors and is not necessarily correlated with the length of the metatarsus. Other types of posterior marks in dinosaur footprints, such as drag and slip marks, are reviewed.

@article{doi101111pala12584,
    author = "Lallensack, Jens N. and Farlow, James O. and Falkingham, Peter",
    title = "A new solution to an old riddle: elongate dinosaur tracks explained as deep penetration of the foot, not plantigrade locomotion",
    year = "2021",
    journal = "Palaeontology",
    abstract = "Abstract The dinosaur track record features numerous examples of trackways with elongated metatarsal marks. Such ‘elongate tracks’ are often highly variable and characterized by indistinct outlines and abbreviated or missing digit impressions. Elongate dinosaur tracks are well‐known from the Paluxy River bed of Texas, where some have been interpreted as ‘man tracks’ by creationists due to their superficially human‐like appearance. The horizontal orientation of the metatarsal marks led to the now widely accepted idea of a facultative plantigrade, or ‘flat‐footed’, mode of locomotion in a variety of dinosaurian trackmakers small to large. This hypothesis, however, is at odds with the observation that elongate tracks do not indicate reduced locomotion speeds and increased pace angulation values, but instead are correlated with low anatomical fidelity. We here interpret elongate tracks as deep penetrations of the foot in soft sediment. Sediment may collapse above parts of the descending foot, leaving a shallow surface track that preserves a metatarsal mark. The length of a metatarsal mark is determined by multiple factors and is not necessarily correlated with the length of the metatarsus. Other types of posterior marks in dinosaur footprints, such as drag and slip marks, are reviewed.",
    url = "https://doi.org/10.1111/pala.12584",
    doi = "10.1111/pala.12584",
    openalex = "W4200240294",
    references = "doi1010079789400904095, doi10103820167, doi10108002724634199510011574, doi1010800272463420171314298, doi1010800272463420201781142, doi101080104209402013817405, doi10108010420940601006859, doi101111j146979981983tb02087x, doi101111pala12502, doi101111pala12584, doi101242jeb1051147, doi101371journalpone0004591, doi1023071311183, doi1026879529, doi10297960650, doi105860choice273305, doi105860choice393984, doi107717peerj2059, openalexw114509570, openalexw2618301958, openalexw2619609965"
}

@misc{crossref2022texas,
    title = "Texas drought uncovers dinosaur footprints from 113 million years ago",
    year = "2022",
    booktitle = "AAAS Articles DO Group",
    url = "https://doi.org/10.1126/science.ade5879",
    doi = "10.1126/science.ade5879",
    openalex = "W4293253937"
}

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"
}

The Carreras Pampa tracksite in the Torotoro National Park, Bolivia, records a wealth of dinosaur tracks, tail traces, and swim tracks. In this study, we report 1321 trackways and 289 solitary tracks, totaling 16,600 theropod tracks, 280 swim trackways, totaling 1,378 swim tracks, and several trackways with tail traces. Numerous avian tracks occur locally and are associated with the theropod tracks. These tracks and trackways are located within nine study sites of the same exposed tracking surface with a total area of approximately 7485 m2. We describe eight preservation styles and 11 morphotypes for walking tracks, and three morphotypes for swim tracks. Tracks range in size from miniature to large. The range of track sizes and the diversity of morphotypes suggest that the Carreras Pampa tracksite represents a diverse group of trackmakers. Track depths vary from very shallow to very deep both within and among trackways, suggesting that the rheological conditions of the sites changed in time and space. We present estimates of the speeds, gaits, and sizes of trackmakers and propose diverse behaviors indicated by the trackways. Notably, trackways at the Carreras Pampa tracksite indicate that a significantly higher proportion of trackmakers had relative stride lengths above 2.0 compared to other sites. The trackways show a strong, bimodal orientation, probably moving along the paleocoastline. Other forms of bioturbation and fossils were found in association with the tracks. We compare our findings at the Carreras Pampa track site to those from other sites in various locations. The quality of preservation, the exceptionally high number of tracks, and the diversity of behaviors recorded make the Carreras Pampa tracksite one of the premier dinosaur track sites in the world.

@article{doi101371journalpone0335973,
    author = "Esperante, Raúl and McLarty, Jeremy A. and Nick, Kevin E. and Pompe, Lance and Biaggi, Roberto E. and Medina, Helen D. Baltazar and Llempen, Nelson A. and Silvestri, Arturo and Quispe, Lourdes Lidia Mamani and Cano, Antonio Joaquín Garre and Saavedra, Wilson Quiroga and Rodríguez, Germán Santos Flor",
    title = "Morphotypes, preservation, and taphonomy of dinosaur footprints, tail traces, and swim tracks in the largest tracksite in the world: Carreras Pampa (Upper Cretaceous), Torotoro National Park, Bolivia",
    year = "2025",
    journal = "PLoS ONE",
    abstract = "The Carreras Pampa tracksite in the Torotoro National Park, Bolivia, records a wealth of dinosaur tracks, tail traces, and swim tracks. In this study, we report 1321 trackways and 289 solitary tracks, totaling 16,600 theropod tracks, 280 swim trackways, totaling 1,378 swim tracks, and several trackways with tail traces. Numerous avian tracks occur locally and are associated with the theropod tracks. These tracks and trackways are located within nine study sites of the same exposed tracking surface with a total area of approximately 7485 m2. We describe eight preservation styles and 11 morphotypes for walking tracks, and three morphotypes for swim tracks. Tracks range in size from miniature to large. The range of track sizes and the diversity of morphotypes suggest that the Carreras Pampa tracksite represents a diverse group of trackmakers. Track depths vary from very shallow to very deep both within and among trackways, suggesting that the rheological conditions of the sites changed in time and space. We present estimates of the speeds, gaits, and sizes of trackmakers and propose diverse behaviors indicated by the trackways. Notably, trackways at the Carreras Pampa tracksite indicate that a significantly higher proportion of trackmakers had relative stride lengths above 2.0 compared to other sites. The trackways show a strong, bimodal orientation, probably moving along the paleocoastline. Other forms of bioturbation and fossils were found in association with the tracks. We compare our findings at the Carreras Pampa track site to those from other sites in various locations. The quality of preservation, the exceptionally high number of tracks, and the diversity of behaviors recorded make the Carreras Pampa tracksite one of the premier dinosaur track sites in the world.",
    url = "https://doi.org/10.1371/journal.pone.0335973",
    doi = "10.1371/journal.pone.0335973",
    openalex = "W4416965703",
    references = "doi101016jpalaeo2021110589, doi105710amghv48i4341, therrien2015dinosaur"
}

Tracksites at Dinosaur State Park were first mapped soon after discovery (East Tracksite, ca. 1966) and more than a decade later (West Tracksite, 1980–1981) using near-vertical low-level photographs and hand-traced footprint outlines. Associated photomosaic images/maps on display at the park are thorough but lack topographic detail. We summarize our use of laser scanning, image capture, and digital photogrammetry workflow to map, model, measure, and visualize the East Tracksite (535 m2) and the West Tracksite (335 m2). The East Tracksite, buried since circa 1978, is modeled from 54 historical photographs (ca. 1969) with limited success. Only covering 67% of the tracksite, this model is topographically noisy and is not suitable for detailed topographic measurement due to lower image quality, limited image overlap, and the absence of independent topographic control. In contrast, the West Tracksite models in great detail and includes 751 mostly Eubrontes prints, 89 “swim” traces, other unusual structures, and micro-topographic variations for the three primary host sedimentary layers (lowermost wave-rippled L0, overlain by L1, and wave-rippled L2). Traces are most numerous on L1 (approximately 50% of Eubrontes, nearly all “swim” prints, and one of two varieties of enigmatic structures). Unidentified structures include double-imprinted 0.5–1.5 m–long curved and segmented grooves on L0, and an approximately 2.3 m–long series of alternating oval impressions on L1. Trackways with six or more prints reveal several groups with similar but widely distributed orientations. Footprints within individual trackways are deeper, larger, and more voluminous on L0 than on L1 and/or L2, which may imply more easily deformed L0 sediments, although L1 and/or L2 tracks often are partially sediment-filled thereby diminishing track depths and volumes.

@article{doi1033740140660106,
    author = "Hyatt, James A. and Farlow, James O. and Galton, Peter M. and Getty, Patrick R.",
    title = "Documenting Footprints for Tracksites at Dinosaur State Park, Rocky Hill, Connecticut",
    year = "2025",
    journal = "Bulletin of the Peabody Museum of Natural History",
    abstract = "Tracksites at Dinosaur State Park were first mapped soon after discovery (East Tracksite, ca. 1966) and more than a decade later (West Tracksite, 1980–1981) using near-vertical low-level photographs and hand-traced footprint outlines. Associated photomosaic images/maps on display at the park are thorough but lack topographic detail. We summarize our use of laser scanning, image capture, and digital photogrammetry workflow to map, model, measure, and visualize the East Tracksite (535 m2) and the West Tracksite (335 m2). The East Tracksite, buried since circa 1978, is modeled from 54 historical photographs (ca. 1969) with limited success. Only covering 67\% of the tracksite, this model is topographically noisy and is not suitable for detailed topographic measurement due to lower image quality, limited image overlap, and the absence of independent topographic control. In contrast, the West Tracksite models in great detail and includes 751 mostly Eubrontes prints, 89 “swim” traces, other unusual structures, and micro-topographic variations for the three primary host sedimentary layers (lowermost wave-rippled L0, overlain by L1, and wave-rippled L2). Traces are most numerous on L1 (approximately 50\% of Eubrontes, nearly all “swim” prints, and one of two varieties of enigmatic structures). Unidentified structures include double-imprinted 0.5–1.5 m–long curved and segmented grooves on L0, and an approximately 2.3 m–long series of alternating oval impressions on L1. Trackways with six or more prints reveal several groups with similar but widely distributed orientations. Footprints within individual trackways are deeper, larger, and more voluminous on L0 than on L1 and/or L2, which may imply more easily deformed L0 sediments, although L1 and/or L2 tracks often are partially sediment-filled thereby diminishing track depths and volumes.",
    url = "https://doi.org/10.3374/014.066.0106",
    doi = "10.3374/014.066.0106",
    openalex = "W4409780314",
    references = "doi101111pala12584, doi102110jsr201957, doi1033740140660108, farlow2022pedal"
}