@article{doi101098rstb19610007, author = "Walker, A. D.", title = "Triassic reptiles from the elgin area: Stagonolepis, Dasygnathus and their allies", year = "1961", journal = "Philosophical transactions of the Royal Society of London. Series B, Biological sciences", abstract = "Abstract The maxilla named by T. H. Huxley Dasygnathus longidens, from the Trias of Findrassie near Elgin, is re-described. A pterygoid from the same locality is referred to this species and described for the first time. These two bones indicate a large, carnivorous pseudosuchian apparently allied to Erythrosuchus. A detailed description is given of the osteology of the pseudosuchian Stagonolepis, amplified by a large number of hitherto undescribed specimens. The material (considered to represent at least twenty-one individuals) shows an almost complete segregation into two size-groups, distinguished by only a few minor morphological differences of the postcranial skeleton. The larger and small individuals are considered to be males and females respectively, of the one species S. robertsoni Agassiz. Study of Stagonolepis has demonstrated its close relationship to Aetosaurus from the Stubensandstein (Keuper) of Stuttgart. The latter genus, however, was in urgent need of revision. Accordingly a brief account is included of the principal respects in which previous descriptions of this form require modification. Specimens referred by von Huene (1921) to A. crassicauda are shown to have been misidentified in many cases; this material is a composite of a small coelurosaur and a true aetosaurid. Some modifications are also suggested to previous accounts of Typothorax and Desmatosuchus from the Trias of North America, and new restorations are given of the skulls of these forms. The extremely close relationship between Stagonolepis and Aëtosaurus, perhaps even indicating generic identity, makes unavoidable the merging of the two families previously founded on these genera. On grounds of priority the name Aetosauridae is retained for the taxonomic unit which includes Aëtosaurus, Stagonolepis, Typothorax and Desmatosuchus as principal members. A restricted diagnosis of the family Aëtosauridae is given, based on the above four forms, and this is followed by a review of the genera which have from time to time been included in the former families Stagonolepidae and Aëtosauridae. The great majority of these genera are excluded from the group as now defined. Possible evolutionary trends within the family are briefly outlined; the sequence of increase of specialization appears to be Aëtosaurus, Stagonolepis, Typothorax, Desmatosuchus. The conclusions of Dollo (1884), Adams (1919) and others concerning the function of the preorbital fossa in archosaurian reptiles are endorsed, and it is suggested that a trend towards the reduction of the anterior pterygoid muscle took place in aetosaurids, in parallel with a similar trend in ornithischian dinosaurs. Many features of the skeleton of aetosaurids recall the Ornithischia. These include the elongate naris, reduced dentition, vertical or forwardly inclined quadrate, slipper-shaped jaw, small skull and well-developed dermal armour. However, a direct ancestor-descendant relationship appears to be ruled out by the position of the supratemporal fossa, reduction of the infratemporal opening, probable loss of the coronoid and typically pseudosuchian pubis, although the aëtosaurids may well lie close to the root-stock of the Ornithischia. The mode of life of the aetosaurids is considered, and it is concluded that these animals were herbivorous, or possibly feeders upon invertebrates obtained, in the case of Stagonolepis at least, by digging with the peculiar expanded snout-tip and dentary rostrum. A simple muscular mechanism is postulated whereby this could be effected. The stratigraphical implications of these studies are briefly examined and the suggestion, based primarily on the close relationship between Stagonolepis and Aëtosaurus, is put forward that the Triassic sandstone of Elgin occupies a higher horizon than has previously been considered.", url = "https://doi.org/10.1098/rstb.1961.0007", doi = "10.1098/rstb.1961.0007", openalex = "W1973479491", references = "doi101002jmor1050010106, doi101111j146363951921tb00489x, doi101111j146979981913tb06148x, doi101111j174966321918tb55350x, doi101126science411064763, doi101144gsljgs1859015010254, doi101144gsljgs1875031010429, doi102475ajss417101377, doi105962bhltitle54054, doi105962bhltitle5752, openalexw1528089848" } @article{benton1983dinosaur, author = "Benton, Michael J.", title = "Dinosaur Success in the Triassic: A Noncompetitive Ecological Model", year = "1983", journal = "The Quarterly Review of Biology", url = "https://doi.org/10.1086/413056", doi = "10.1086/413056", number = "1", openalex = "W2042835760", pages = "29-55", volume = "58", references = "doi101073pnas722646, doi10108003115517708527763, doi101086283249, doi101098rstb19610007, doi101098rstb19740001, doi101130spe89p63, openalexw1539997818, openalexw2261909166, openalexw3135630760, spotila1973a" } @article{benton1983dinosaur1, author = "Benton, M. J", title = "Dinosaur success in the Triassic", year = "1983", journal = "A noncompetitive ecological model: Quarterly Review of Biology, v. 58, p. 29-55", note = "talkorigins\_source = {true}; raw\_reference = {Benton, M. J., 1983, Dinosaur success in the Triassic: A noncompetitive ecological model: Quarterly Review of Biology, v. 58, p. 29-55.}" } @misc{mcgowen1983the2, author = "McGowen, C", title = "The Successful Dragons", year = "1983", howpublished = "Toronto, Samuel Stevens and Co", note = "talkorigins\_source = {true}; raw\_reference = {McGowen, C., 1983, The Successful Dragons: Toronto, Samuel Stevens and Co.}" } @article{doi1023073514751, author = "Beerbower, Richard and Padian, Kevin", title = "The Beginning of the Age of Dinosaurs", year = "1989", journal = "Palaios", abstract = "The record of life on land has been a principal concern of historical biology not only because of our fascination with our own past (and with giants, dragons, and other ancient monsters) but because of special opportunities and challenges for development of methods, principles, and concepts of explanation. The Beginning of the Age of Dinosaurs treats an intriguing phase of that history, one that included the first appearance of dinosaurs, and mammals, the extinction or near extinction of many clades of vertebrates, and extensive changes in plant associations. Further, the patterns of change (and of stasis) raise general questions about macroecologic and macroevolutionary processes and factors and even about the roles of chance and determination in biological history. Although the book was published initially in 1986 (and was based on a 1984 symposium sponsored by the Society of Vertebrate Paleontologists), its content remains current and its release in paperback form (for $34.50 rather than $75.00 for the hardcover version) justifies a review even at this late date. The Introduction and the Summary and Prospectus, written by the editor, Kevin Padian, demonstrate the significance of the interval from mid-Triassic to early Jurassic-particularly for vertebrates on land. Advanced mammal-like reptiles (therapsids) dominate lower Triassic assemblages in abundance, taxonomic diversity, and ecological variety; non-therapsids (mostly archosaurs) are rare elements and apparently of little ecological importance. In upper Triassic and lower Jurassic assemblages the situation is reversed, therapsids rare with limited diversity and variety but archosaurs abundant, diverse and varied. The archosaur expansion starts in middle of the succession; pterodactyls, crocodylomorphs, and dinosaurs appear (as archosaur subclades) in approximate coincidence with a marked decline in therapsids. Mammals (at least 3 subclades) occur along with two other subclades of very mammal-like therapsids very close to the top. In the upper Triassic two relatively sharp breaks in faunal composition appear, one relatively low, in the top of the Carnian and base of the Norian stages (around 225 Ma), and one higher, at the top of the Norian (around 215 Ma). These breaks, if real and not a consequence of miscorrelations or gaps in sampling, suggest high rates of taxonomic extinction and origination and have been interpreted as intervals of catastrophic extinction. These changes coincide more or less with some in the flora (except that the latter seem continuous rather than stepped) and thus with overall changes in terrestrial ecosystems. Radically different explanations have been offered for these patterns, at one extreme a deterministic argument from the competitive superiority of dinosaurs to the other, an opportunistic one based on chance differences in survival through episodes of mass extinction. This book can be viewed (and reviewed) as an extended example of analysis and interpretation in historical biology. The concerns of the discipline are twofold, chronicle and narrative (the concepts those of O'Hara, 1988). Chronicle comprises when, what, and where; narrative, how. A chronicle extends of course beyond description and chronologic ordering of fossils to paleobiogeographic, paleoecologic, and phylogenetic reconstructions. The latter derive from patterns in form and occurrence of fossils as analyzed in terms of taphonomic, constructional, functional, and phylogenetic processes and factors (viz Seilacher, 1970) and of stratigraphic and geographic distribution. Each reconstruction represents a particular state, and stratigraphic analysis arranges these reconstructions into a chronicle. Narrative, in contrast, involves explanation of the patterns (temporal, geographic, ecologic and phyletic) in the chronicle by a sequence of biological and physical circumstances and by evolutionary processes and factors (genetic, phylogenetic, and ecological). Of the 26 papers in this volume, 24 focus primarily on the chronicle and are dominated by consideration of what-when, i.e., the stratigraphic distribution of various groups of fossils, and of what-how, i.e., the phylogenetic and functional analyses. Among those in the what-when group are papers by Colbert on historical aspects of upper Triassic-lower Jurassic stratigraphy, by Ash on fossil plants, by Olsen and Baird on the ichnogenus Atreipus, by Chatterjee and by Parrish and Carpenter on vertebrates of the Dockum Group (Texas and New Mexico), and by Long and Padian on biostratigraphy of the Chinle Formation (Arizona). Also best included here are the studies by McCune and Schaeffer on Triassic and Jurassic fishes, Gaffney on turtles, Clemens on mammals, Olson and Padian on crocodylomorph ichnogenera, Sun and Cui on saurishians from the lower Lufeng (China), Clark and Fastovsky on the vertebrates of the Glen Canyon Group (Arizona), Haubold on archosaur trackways, Sigogneau-Russell, Frank, and Hemmerle on a new family of Triassic", url = "https://doi.org/10.2307/3514751", doi = "10.2307/3514751", openalex = "W2320472492", references = "doi101017cbo9780511608551, doi1023072807146, doi1023072992272" } @article{doi101098rstb19950125, author = "Upchurch, Paul", title = "The evolutionary history of sauropod dinosaurs", year = "1995", journal = "Philosophical Transactions of the Royal Society B Biological Sciences", abstract = "Abstract Most recent studies of dinosaur phylogeny have concentrated on theropods and ornithischians. As a result, the evolutionary relationships of sauropod dinosaurs are poorly understood. In this paper previous studies of sauropod phylogeny are reviewed and contrasted with the results of a recent cladistic analysis. This analysis forms the basis for a reconstruction of sauropod phylogeny. Sauropods diverged from other dinosaurs at some time in the Upper Triassic, but a large part of their early history is totally unknown. Vulcanodonis currently the most primitive sauropod. Many, but perhaps not all, of the Jurassic Chinese sauropods form a monophyletic radiation (the Euhelopodidae) which may reflect the geographic isolation of China during the Lower Jurassic. Members of the Euhelopodidae, such as Mamenchisaurus, are not considered to be closely related to the Diplodocidae. ‘Forked’ chevrons, which have played such an important role in previous studies of sauropod phylogeny, are here considered to have evolved twice within the Sauropoda. This convergence may reflect a correlation between chevron shape and the use of the tail as a weapon within these two sauropod families. The ‘Neosauropoda’ (sister group to the Euhelopodidae) contains the Brachiosauridae, Camarasauridae and the new superfamilies Titanosauroidea and Diplodocoidea. The Cetiosauridae (here defined in a rather restricted sense) is also provisionally included within the Neosauropoda, but may be removed in future studies. The enigmatic Upper Cretaceous sauropod, Opisthocoelicaudia, is thought to be the sister taxon to the Titanosauridae and not a camarasaurid as previously suggested. The Diplodocoidea contains two well established families, the Dicraeosauridae and Diplodocidae, and the new family Nemegtosauridae. Finally, an overview of sauropod phylogeny is compared with recently published palaeogeographic reconstructions. There are many difficulties associated with the analysis of sauropod biogeographic distribution. Nevertheless, some aspects of sauropod phylogeny may be linked to the break-up of Laurasia and Gondwanaland during the Jurassic and Cretaceous.", url = "https://doi.org/10.1098/rstb.1995.0125", doi = "10.1098/rstb.1995.0125", openalex = "W2026763967", references = "doi10102992jb00648, doi10108002724634199410011538, doi101126science2665183267, doi101139e93176, doi1023071292217, doi103989egeol8743extra625, doi105281zenodo16171435, doi105962bhlpart4439, doi105962bhltitle60562, doi105962p234849, openalexw3114518543" } @article{sereno1997the, author = "Sereno, Paul C.", title = "THE ORIGIN AND EVOLUTION OF DINOSAURS", year = "1997", journal = "Annual Review of Earth and Planetary Sciences", abstract = "▪ Abstract Phylogenetic studies and new fossil evidence have yielded fundamental insights into the pattern and timing of dinosaur evolution and the emergence of functionally modern birds. The dinosaurian radiation began in the Middle Triassic, significantly predating the global dominance of dinosaurs by the end of the period. The phylogenetic history of ornithischian and saurischian dinosaurs reveals evolutionary trends such as increasing body size. Adaptations to herbivory in dinosaurs were not tightly correlated with marked floral replacements. Dinosaurian biogeography during the era of continental breakup principally involved dispersal and regional extinction.", url = "https://doi.org/10.1146/annurev.earth.25.1.435", doi = "10.1146/annurev.earth.25.1.435", number = "1", openalex = "W2081551955", pages = "435-489", volume = "25", references = "benton1983dinosaur, chinsamy1994dinosaur, crossref1976allosaurus, crossref1995systematics, doi101007978364268836217, doi10100797836426953391, doi1010160031018272900491, doi1010160195667191900155, doi101017cbo9780511608551, doi101017cbo9781139167826, doi101017s0022336000026706, doi101017s0094837300004310, doi101038274661a0, doi101038378774a0, doi101038385247a0, doi10108002724634199110011426, doi10108002724634199310011490, doi10108002724634199410011538, doi10108002724634199510011250, doi10108002724634199510011575, doi101086284406, doi101086407902, doi101093clinids222240, doi101098rstb19910056, doi101098rstb19950125, doi101111j109583121976tb00244x, doi101111j109600311988tb00514x, doi101126science24348951145, doi101126science2555046845, doi101126science2645160828, doi101126science2665183267, doi101126science2665186779, doi101126science2725264986, doi101139e93176, doi101139e93179, doi101139e93187, doi101146annurevea03050175000415, doi101146annureven10010165000525, doi101353book34649, doi1023071441916, doi1023072421859, doi105281zenodo16171435, doi105281zenodo16246150, doi105479si03629236110i, doi105860choice323881, doi105860choice331556, doi105962p226819, openalexw2603028126, openalexw2788234611, openalexw3146596760, openalexw39955589, parrish1987late, rowe1989a, vonhuene1923carnivorous, wilson1985stenonychosaurus" } @article{delahoyde1998medieval, author = "Delahoyde, Michael", title = "Medieval Dragons and Dinosaur Films", year = "1998", journal = "Popular Culture Review", url = "https://doi.org/10.1002/j.2831-865x.1998.tb00111.x", doi = "10.1002/j.2831-865x.1998.tb00111.x", number = "1", openalex = "W4396236598", pages = "17-30", volume = "9", references = "doi101086352197, openalexw1489356600, openalexw1533135399, openalexw604593164" } @article{doi101126science28454232137, author = "Sereno, Paul C.", title = "The Evolution of Dinosaurs", year = "1999", journal = "Science", abstract = "The ascendancy of dinosaurs on land near the close of the Triassic now appears to have been as accidental and opportunistic as their demise and replacement by therian mammals at the end of the Cretaceous. The dinosaurian radiation, launched by 1-meter-long bipeds, was slower in tempo and more restricted in adaptive scope than that of therian mammals. A notable exception was the evolution of birds from small-bodied predatory dinosaurs, which involved a dramatic decrease in body size. Recurring phylogenetic trends among dinosaurs include, to the contrary, increase in body size. There is no evidence for co-evolution between predators and prey or between herbivores and flowering plants. As the major land masses drifted apart, dinosaurian biogeography was molded more by regional extinction and intercontinental dispersal than by the breakup sequence of Pangaea.", url = "https://doi.org/10.1126/science.284.5423.2137", doi = "10.1126/science.284.5423.2137", openalex = "W1974320804", references = "brouwers1987dinosaurs, coria1995a, doi101007978364268836217, doi10100797836426953391, doi1010160031018272900491, doi1010160031018282900852, doi1010160198025483901334, doi101017s0022336000026706, doi101017s0094837300004310, doi101017s0094837300026543, doi10103820167, doi101038248168a0, doi101038277560a0, doi10103831927, doi10103832642, doi10103834356, doi101038378774a0, doi101038385247a0, doi101038387390a0, doi10108002724634199010011815, doi10108002724634199110011386, doi10108002724634199210011473, doi10108002724634199310011490, doi10108002724634199410011523, doi10108002724634199510011250, doi10108002724634199810011101, doi10108002724634199810011115, doi101093oso97801985491780010001, doi101098rstb19950125, doi101111j109636421998tb00569x, doi101111j1469185x1997tb00024x, doi101111j155856461973tb05912x, doi101111j155856461996tb04496x, doi101111j174966321940tb57047x, doi101111j216409471940tb00068x, doi101126science2645160828, doi101126science2725264986, doi101126science27953581915, doi101126science28053661048, doi101126science28253921298, doi101126science2845414616, doi101127njgpa210199841, doi101139e93187, doi101146annurevea03050175000415, doi101146annurevearth251435, doi1015159780691224244, doi1023071292217, doi1023073514751, doi1023073515466, openalexw1528487914, rowe1989a, sereno1997the" } @article{doi101126science1065522, author = "Olsen, Paul E. and Kent, Dennis V. and Sues, Hans‐Dieter and Koeberl, Christian and Huber, Heinz and Montanari, Alessandro and Rainforth, Emma C. and Fowell, Sarah J. and Szajna, Michael J. and Hartline, B. W.", title = "Ascent of Dinosaurs Linked to an Iridium Anomaly at the Triassic-Jurassic Boundary", year = "2002", journal = "Science", abstract = "Analysis of tetrapod footprints and skeletal material from more than 70 localities in eastern North America shows that large theropod dinosaurs appeared less than 10,000 years after the Triassic-Jurassic boundary and less than 30,000 years after the last Triassic taxa, synchronous with a terrestrial mass extinction. This extraordinary turnover is associated with an iridium anomaly (up to 285 parts per trillion, with an average maximum of 141 parts per trillion) and a fern spore spike, suggesting that a bolide impact was the cause. Eastern North American dinosaurian diversity reached a stable maximum less than 100,000 years after the boundary, marking the establishment of dinosaur-dominated communities that prevailed for the next 135 million years.", url = "https://doi.org/10.1126/science.1065522", doi = "10.1126/science.1065522", openalex = "W2107051375", references = "doi1010160031018295001719, doi101126science22546661030, doi101126science3616622, doi1023073514751, doi105860choice332752, doi107312lock90868" } @article{doi101017s1464793103006134, author = "Evans, Susan E.", title = "At the feet of the dinosaurs: the early history and radiation of lizards", year = "2003", journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society", abstract = "Lizards, snakes and amphisbaenians together constitute the Squamata, the largest and most diverse group of living reptiles. Despite their current success, the early squamate fossil record is extremely patchy. The last major survey of squamate palaeontology and evolution was published 20 years ago. Since then, there have been major changes in systematic theory and methodology, as well as a steady trickle of new fossil finds. This review examines our current understanding of the first 150 million years of squamate evolution in the light of the new data and changing ideas. Contrary to previous reports, no squamate fossils are currently documented before the Jurassic. Nonetheless, indirect evidence predicts that squamates had evolved by at least the middle Triassic, and had diversified into existing major lineages before the end of this period. There is thus a major gap in the squamate record at a time when key morphological features were evolving. With the exception of fragmentary remains from Africa and India, Jurassic squamates are known only from localities in northern continents (Laurasia). The situation improves in the Early Cretaceous, but the southern (Gondwanan) record remains extremely poor. This constrains palaeobiogeographic discussion and makes it difficult to predict centres of origin for major squamate clades on the basis of fossil evidence alone. Preliminary mapping of morphological characters onto a consensus tree demonstrates stages in the sequence of acquisition for some characters of the skull and postcranial skeleton, but many crucial stages--most notably those relating to the acquisition of squamate skull kinesis--remain unclear.", url = "https://doi.org/10.1017/s1464793103006134", doi = "10.1017/s1464793103006134", openalex = "W2170009771", references = "doi101002jmor1051110306, doi10108000222938400770131, doi10108002724634199210011475, doi101098rstb19830079, doi101111j109636421978tb00376x, doi101111j136531211990tb00103x, doi1016710272463420020220286lftlca20co2, doi105860choice325663, openalexw2261909166, openalexw337536883" } @article{doi101671a1097, author = "Dzik, Jerzy", title = "A beaked herbivorous archosaur with dinosaur affinities from the early Late Triassic of Poland", year = "2003", journal = "Journal of Vertebrate Paleontology", abstract = "Abstract An accumulation of skeletons of the pre-dinosaur Silesaurus opolensis, gen. et sp. nov. is described from the Keuper (Late Triassic) claystone of Krasiejów in southern Poland. The strata are correlated with the late Carnian Lehrberg Beds and contain a diverse assemblage of tetrapods, including the phytosaur Paleorhinus, which in other regions of the world co-occurs with the oldest dinosaurs. A narrow pelvis with long pubes and the extensive development of laminae in the cervical vertebrae place S. opolensis close to the origin of the clade Dinosauria above Pseudolagosuchus, which agrees with its geological age. Among the advanced characters is the beak on the dentaries, and the relatively low tooth count. The teeth have low crowns and wear facets, which are suggestive of herbivory. The elongate, but weak, front limbs are probably a derived feature.", url = "https://doi.org/10.1671/a1097", doi = "10.1671/a1097", openalex = "W2101751293", references = "doi101016s001669959880123x, doi101016s0031018298001175, doi101038361064a0, doi10108002724634199110011386, doi10108002724634199110011426, doi10108002724634199910011178, doi101098rstb19990489, doi10718895fylantbak30809522, openalexw2310875238, openalexw2788234611, openalexw606525048, openalexw616953834, sereno1997the" } @article{godefroit2003late, author = "Godefroit, Pascal and Knoll, Fabien", title = "Late Triassic dinosaur teeth from southern Belgium", year = "2003", journal = "Comptes Rendus Palevol", url = "https://doi.org/10.1016/s1631-0683(03)00006-x", doi = "10.1016/s1631-0683(03)00006-x", number = "1", pages = "3-11", volume = "2" } @article{doi101126science1120125, author = "Sander, P. Martin and Klein, Nicole", title = "Developmental Plasticity in the Life History of a Prosauropod Dinosaur", year = "2005", journal = "Science", abstract = "Long-bone histology indicates that the most common early dinosaur, the prosauropod Plateosaurus engelhardti from the Upper Triassic of Central Europe, had variable life histories. Although Plateosaurus grew at the fast rates typical for dinosaurs, as indicated by fibrolamellar bone, qualitative (growth stop) and quantitative (growth-mark counts) features of its histology are poorly correlated with body size. Individual life histories of P. engelhardti were influenced by environmental factors, as in modern ectothermic reptiles, but not in mammals, birds, or other dinosaurs.", url = "https://doi.org/10.1126/science.1120125", doi = "10.1126/science.1120125", openalex = "W2172140341", references = "doi101016jtree200508012, doi101016s0753396903000053, doi101111j00310239200300301x, doi10560219780801881206" } @article{doi101017s1477201906001970, author = "Langer, Max C. and Benton, Michael J.", title = "Early dinosaurs: A phylogenetic study", year = "2006", journal = "Journal of Systematic Palaeontology", abstract = "Synopsis Early dinosaur evolution has been the subject of several phylogenetic studies and the position of certain basal forms is currently debated. This is the case for the oldest known members of the group, excavated from the Late Triassic Ischigualastian beds of South America, such as Herrerasaurus, Eoraptor, Pisanosaurus, Saturnalia and Staurikosaurus. A new cladistic analysis of the early dinosaur radiation was performed to assess the relationships among the three major clades (Ornithischia, Sauropodomorpha and Theropoda) and to define the phylogenetic position of the basal members of the group. The most parsimonious hypothesis has Silesaurus opolensis as the sister taxon to a dichotomy including monophyletic Saurischia and Ornithischia. The latter includes Pisanosaurus mertii, and the former all other well‐known Triassic dinosaurs. Saurischia is composed of two major monophyletic groups: Herrerasauridae (including Herrerasaurus ischigualastensis and Staurikosaurus pricei) and Eusaurischia (including the theropod and sauropodomorph lineages), while Eoraptor lunensis appears to represent the sister taxon to Eusaurischia. Saturnalia tupiniquim is a stem‐taxon to Sauropodomorpha and Guaibasaurus candelariensis might belong to the theropod branch. Some of these hypotheses are, however, not strongly supported. Especially uncertain are the affinities of Silesaurus and Guaibasaurus. The latter can only be safely regarded as a saurischian, while the former might belong to the ornithischian lineage. The dinosaurian affinities of Eoraptor and Herrerasauridae are strongly supported. Yet, the possibility that they (especially Eoraptor) represent basal theropods, rather than basal saurischians, cannot be dismissed. In fact, basal saurischian evolution is still too poorly understood for a definitive hypothesis of relationships to be presented.", url = "https://doi.org/10.1017/s1477201906001970", doi = "10.1017/s1477201906001970", openalex = "W2106077668", references = "cuny1993revision, doi101007bf00377897, doi101007bf02985709, doi101007bf02986571, doi101007bf02988144, doi101016s001669959880123x, doi101017cbo9780511608377010, doi10108002724634199010011815, doi10108002724634199310011511, doi10108002724634199910011124, doi101093oxfordjournalsafrafa100309, doi101098rspl18870117, doi101098rstb19850092, doi101111j00310239200300301x, doi101111j109600311993tb00209x, doi101111j109600311994tb00179x, doi101111j109636422001tb01313x, doi101111j150239311985tb00690x, doi101111j155856461985tb00420x, doi101111j155856461988tb02497x, doi101126science2562999, doi101671a1097, doi1023072408678, doi1023073889334, doi105281zenodo1040385, doi105281zenodo16246150, doi105281zenodo16492064, doi105281zenodo16651680, doi105281zenodo16692311, doi105281zenodo4664674, doi105860choice392183, doi105962bhlpart22965, galton1977onstaurikosaums, openalexw2261909166, openalexw2560671010, openalexw2991310333, openalexw3190253505, openalexw606525048, openalexw638862129, smith1990osteology" } @article{doi101126science1161833, author = "Brusatte, Stephen L. and Benton, Michael J. and Ruta, Marcello and Lloyd, Graeme T.", title = "Superiority, Competition, and Opportunism in the Evolutionary Radiation of Dinosaurs", year = "2008", journal = "Science", abstract = {The rise and diversification of the dinosaurs in the Late Triassic, from 230 to 200 million years ago, is a classic example of an evolutionary radiation with supposed competitive replacement. A comparison of evolutionary rates and morphological disparity of basal dinosaurs and their chief "competitors," the crurotarsan archosaurs, shows that dinosaurs exhibited lower disparity and an indistinguishable rate of character evolution. The radiation of Triassic archosaurs as a whole is characterized by declining evolutionary rates and increasing disparity, suggesting a decoupling of character evolution from body plan variety. The results strongly suggest that historical contingency, rather than prolonged competition or general "superiority," was the primary factor in the rise of dinosaurs.}, url = "https://doi.org/10.1126/science.1161833", doi = "10.1126/science.1161833", openalex = "W2030637789", references = "benton1983dinosaur, doi101017s009483730001263x, doi101017s009483730001280x, doi101017s1477201907002040, doi101093oso97801985052350010001, doi101111j14754983200600614x, doi101111j155856461971tb01922x, doi101126science1065522, doi101126science1084786, doi101126science1143325, doi101126science2314734129, doi101126science28454232137, doi101126science28554321386, doi101525california97805202420980010001, doi1041599780674417922, doi105860choice396411" } @article{doi101111j10963642200900631x, author = "Butler, Richard J.", title = "The anatomy of the basal ornithischian dinosaur Eocursor parvus from the lower Elliot Formation (Late Triassic) of South Africa", year = "2009", journal = "Zoological Journal of the Linnean Society", abstract = "Ornithischia is a morphologically and taxonomically diverse clade of dinosaurs that originated during the Late Triassic and were the dominant large-bodied herbivores in many Cretaceous ecosystems. The early evolution of ornithischian dinosaurs is poorly understood, as a result in part of a paucity of fossil specimens, particularly during the Triassic. The most complete Triassic ornithischian dinosaur yet discovered is Eocursor parvus from the lower Elliot Formation (Late Triassic: Norian-Rhaetian) of Free State, South Africa, represented by a partial skull and relatively complete postcranial skeleton. Here, the anatomy of Eocursor is described in detail for the first time, and detailed comparisons are provided to other basal ornithischian taxa. Eocursor is a small-bodied taxon (approximately 1 m in length) that possesses a plesiomorphic dentition consisting of unworn leaf-shaped crowns, a proportionally large manus with similarities to heterodontosaurids, a pelvis that contains an intriguing mix of plesiomorphic and derived character states, and elongate distal hindlimbs suggesting well-developed cursorial ability. The ontogenetic status of the holotype material is uncertain. Eocursor may represent the sister taxon to Genasauria, the clade that includes most of ornithischian diversity, although this phylogenetic position is partially dependent upon the uncertain phylogenetic position of the enigmatic and controversial clade Heterodontosauridae.", url = "https://doi.org/10.1111/j.1096-3642.2009.00631.x", doi = "10.1111/j.1096-3642.2009.00631.x", openalex = "W1944447591", references = "doi10100797836426953391, doi101007bf00377897, doi101017s1477201907002271, doi10108002724634199610011283, doi10108002724634199910011178, doi101098rspl18870117, doi101126science28454232137, doi101146annurevearth251435, doi1015468gbdyof, doi1023073514751, doi105860choice353642, godefroit2003late, openalexw3215057009, padian1990the" } @article{doi101111j1469185x200900094x, author = "Langer, Max C. and Ezcurra, Martín D. and Bittencourt, Jonathas S. and Novas, Fernando E.", title = "The origin and early evolution of dinosaurs", year = "2009", journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society", abstract = {The oldest unequivocal records of Dinosauria were unearthed from Late Triassic rocks (approximately 230 Ma) accumulated over extensional rift basins in southwestern Pangea. The better known of these are Herrerasaurus ischigualastensis, Pisanosaurus mertii, Eoraptor lunensis, and Panphagia protos from the Ischigualasto Formation, Argentina, and Staurikosaurus pricei and Saturnalia tupiniquim from the Santa Maria Formation, Brazil. No uncontroversial dinosaur body fossils are known from older strata, but the Middle Triassic origin of the lineage may be inferred from both the footprint record and its sister-group relation to Ladinian basal dinosauromorphs. These include the typical Marasuchus lilloensis, more basal forms such as Lagerpeton and Dromomeron, as well as silesaurids: a possibly monophyletic group composed of Mid-Late Triassic forms that may represent immediate sister taxa to dinosaurs. The first phylogenetic definition to fit the current understanding of Dinosauria as a node-based taxon solely composed of mutually exclusive Saurischia and Ornithischia was given as "all descendants of the most recent common ancestor of birds and Triceratops". Recent cladistic analyses of early dinosaurs agree that Pisanosaurus mertii is a basal ornithischian; that Herrerasaurus ischigualastensis and Staurikosaurus pricei belong in a monophyletic Herrerasauridae; that herrerasaurids, Eoraptor lunensis, and Guaibasaurus candelariensis are saurischians; that Saurischia includes two main groups, Sauropodomorpha and Theropoda; and that Saturnalia tupiniquim is a basal member of the sauropodomorph lineage. On the contrary, several aspects of basal dinosaur phylogeny remain controversial, including the position of herrerasaurids, E. lunensis, and G. candelariensis as basal theropods or basal saurischians, and the affinity and/or validity of more fragmentary taxa such as Agnosphitys cromhallensis, Alwalkeria maleriensis, Chindesaurus bryansmalli, Saltopus elginensis, and Spondylosoma absconditum. The identification of dinosaur apomorphies is jeopardized by the incompleteness of skeletal remains attributed to most basal dinosauromorphs, the skulls and forelimbs of which are particularly poorly known. Nonetheless, Dinosauria can be diagnosed by a suite of derived traits, most of which are related to the anatomy of the pelvic girdle and limb. Some of these are connected to the acquisition of a fully erect bipedal gait, which has been traditionally suggested to represent a key adaptation that allowed, or even promoted, dinosaur radiation during Late Triassic times. Yet, contrary to the classical "competitive" models, dinosaurs did not gradually replace other terrestrial tetrapods over the Late Triassic. In fact, the radiation of the group comprises at least three landmark moments, separated by controversial (Carnian-Norian, Triassic-Jurassic) extinction events. These are mainly characterized by early diversification in Carnian times, a Norian increase in diversity and (especially) abundance, and the occupation of new niches from the Early Jurassic onwards. Dinosaurs arose from fully bipedal ancestors, the diet of which may have been carnivorous or omnivorous. Whereas the oldest dinosaurs were geographically restricted to south Pangea, including rare ornithischians and more abundant basal members of the saurischian lineage, the group achieved a nearly global distribution by the latest Triassic, especially with the radiation of saurischian groups such as "prosauropods" and coelophysoids.}, url = "https://doi.org/10.1111/j.1469-185x.2009.00094.x", doi = "10.1111/j.1469-185x.2009.00094.x", openalex = "W2121596487", references = "chatterjee2013a, crossref1998encyclopedia, currie2009stratigraphy, doi1010160031018281900924, doi1010160031018295000178, doi101016c20090644421, doi101016jjsames200504002, doi101016jpalaeo200606041, doi101016s0012825203000825, doi101016s0016699580800386, doi101016s0016699583800205, doi101016s0031018298001175, doi101017cbo9780511628948, doi101017s0094837300010575, doi101017s1477201906001970, doi101017s1477201907002040, doi101017s1477201907002246, doi101017s1477201907002271, doi101017s247526300000091x, doi10103820167, doi10106313060577, doi101073pnas0606028103, doi10108002724634199410011538, doi10108002724634199510011271, doi10108002724634199810011115, doi10108002724634199910011124, doi101098rspb20042692, doi101098rspb20080715, doi101098rspl18870117, doi101098rstb19990489, doi101111j109636421985tb01796x, doi101111j10963642200400130x, doi101126science1143325, doi101126science21545391501, doi101126science2645160828, doi101126science2845414616, doi101126science3616622, doi101127njgpa210199841, doi101144gsjgs14720321, doi1012060003009020073021taoeoa20co2, doi101525california97805202420980010001, doi1015468gbdyof, doi1016710272463420020220510toomka20co2, doi1016710272463420072773tclagn20co2, doi101671a1097, doi1023071292217, doi1023071441916, doi1023073889325, doi102475ajss319111253, doi102475ajss32313381, doi104202app20080415, doi10432497802030907329, doi105281zenodo16120887, doi105281zenodo16171435, doi105281zenodo16246150, doi105860choice325663, doi105860choice393984, doi105860choice465038, doi107146moggeosciv32i140904, doi10718895fylantbak30809522, openalexw114509570, openalexw1496509561, openalexw1535663436, openalexw205674743, openalexw2242116350, openalexw2788234611, openalexw2991310333, openalexw3208547338, openalexw3215057009, padian1989presence, rowe1989a, walker1964triassic" } @article{doi101144sp33415, author = "Lucas, Spencer G.", title = "The Triassic timescale based on nonmarine tetrapod biostratigraphy and biochronology", year = "2010", journal = "Geological Society London Special Publications", abstract = "Abstract The Triassic timescale based on nonmarine tetrapod biostratigraphy and biochronology divides Triassic time into eight land-vertebrate faunachrons (LVFs) with boundaries defined by the first appearance datums (FADs) of tetrapod genera or, in two cases, the FADs of a tetrapod species. Definition and characterization of these LVFs is updated here as follows: the beginning of the Lootsbergian LVF=FAD of Lystrosaurus; the beginning of the Nonesian=FAD Cynognathus; the beginning of the Perovkan LVF=FAD Eocyclotosaurus; the beginning of the Berdyankian LVF=FAD Mastodonsaurus giganteus; the beginning of the Otischalkian LVF=FAD Parasuchus; the beginning of the Adamanian LVF=FAD Rutiodon; the beginning of the Revueltian LVF=FAD Typothorax coccinarum; and the beginning of the Apachean LVF=FAD Redondasaurus. The end of the Apachean (= beginning of the Wasonian LVF, near the beginning of the Jurassic) is the FAD of the crocodylomorph Protosuchus. The Early Triassic tetrapod LVFs, Lootsbergian and Nonesian, have characteristic tetrapod assemblages in the Karoo basin of South Africa, the Lystrosaurus assemblage zone and the lower two-thirds of the Cynognathus assemblage zone, respectively. The Middle Triassic LVFs, Perovkan and Berdyankian, have characteristic assemblages from the Russian Ural foreland basin, the tetrapod assemblages of the Donguz and the Bukobay svitas, respectively. The Late Triassic LVFs, Otischalkian, Adamanian, Revueltian and Apachean, have characteristic assemblages in the Chinle basin of the western USA, the tetrapod assemblages of the Colorado City Formation of Texas, Blue Mesa Member of the Petrified Forest Formation in Arizona, and Bull Canyon and Redonda formations in New Mexico. Since the Triassic LVFs were introduced, several subdivisions have been proposed: Lootsbergian can be divided into three sub-LVFs, Nonesian into two, Adamanian into two and Revueltian into three. However, successful inter-regional correlation of most of these sub-LVFs remains to be demonstrated. Occasional records of nonmarine Triassic tetrapods in marine strata, palynostratigraphy, conchostracan biostratigraphy, magnetostratigraphy and radioisotopic ages provide some basis for correlation of the LVFs to the standard global chronostratigraphic scale. These data indicate that Lootsbergian=uppermost Changshingian, Induan and possibly earliest Olenekian; Nonesian=much of the Olenekian; Perovkan=most of the Anisian; Berdyankian=latest Anisian? and Ladinian; Otischalkian=early to late Carnian; Adamanian=most of the late Carnian; Revueltian=early–middle Norian; and Apachean=late Norian–Rhaetian. The Triassic timescale based on tetrapod biostratigraphy and biochronology remains a robust tool for the correlation of nonmarine Triassic tetrapod assemblages independent of the marine timescale.", url = "https://doi.org/10.1144/sp334.15", doi = "10.1144/sp334.15", openalex = "W2085030054", references = "chatterjee2013a, crossref1998encyclopedia, doi101007bf01134434, doi1010160034666791900282, doi101016jgeobios200304008, doi101016jjsames200504002, doi101016s0031018298001175, doi101016s0753396900800026, doi101017cbo9780511564413024, doi101017s0016756807003925, doi10108002724634199910011124, doi10108010420940601006792, doi101098rspb20043047, doi101098rstb19740001, doi101111j146363951921tb00489x, doi101126science1097023, doi101130001676061972833795mrsitu20co2, doi101144sp33413, doi1016710390290218, doi1018814epiiugs2001v24i2004, doi1023073514751, doi104202app20080415, doi1056577ffc5285, doi1056577ffc56302, doi105860choice332752, doi105860choice353642, doi105962bhltitle60647, doi107312lock90868, leanza2004cretaceous, openalexw1532983209, openalexw1535663436, openalexw1998354960, openalexw205674743, openalexw653009579, padian1990the" } @article{doi101111j1469185x201100190x, author = "Benson, Roger and Butler, Richard J. and Carrano, Matthew T. and O’Connor, Patrick M.", title = "Air‐filled postcranial bones in theropod dinosaurs: physiological implications and the ‘reptile’–bird transition", year = "2011", journal = "Biological reviews/Biological reviews of the Cambridge Philosophical Society", abstract = "Pneumatic (air-filled) postcranial bones are unique to birds among extant tetrapods. Unambiguous skeletal correlates of postcranial pneumaticity first appeared in the Late Triassic (approximately 210 million years ago), when they evolved independently in several groups of bird-line archosaurs (ornithodirans). These include the theropod dinosaurs (of which birds are extant representatives), the pterosaurs, and sauropodomorph dinosaurs. Postulated functions of skeletal pneumatisation include weight reduction in large-bodied or flying taxa, and density reduction resulting in energetic savings during foraging and locomotion. However, the influence of these hypotheses on the early evolution of pneumaticity has not been studied in detail previously. We review recent work on the significance of pneumaticity for understanding the biology of extinct ornithodirans, and present detailed new data on the proportion of the skeleton that was pneumatised in 131 non-avian theropods and Archaeopteryx. This includes all taxa known from significant postcranial remains. Pneumaticity of the cervical and anterior dorsal vertebrae occurred early in theropod evolution. This 'common pattern' was conserved on the line leading to birds, and is likely present in Archaeopteryx. Increases in skeletal pneumaticity occurred independently in as many as 12 lineages, highlighting a remarkably high number of parallel acquisitions of a bird-like feature among non-avian theropods. Using a quantitative comparative framework, we show that evolutionary increases in skeletal pneumaticity are significantly concentrated in lineages with large body size, suggesting that mass reduction in response to gravitational constraints at large body sizes influenced the early evolution of pneumaticity. However, the body size threshold for extensive pneumatisation is lower in theropod lineages more closely related to birds (maniraptorans). Thus, relaxation of the relationship between body size and pneumatisation preceded the origin of birds and cannot be explained as an adaptation for flight. We hypothesise that skeletal density modulation in small, non-volant, maniraptorans resulted in energetic savings as part of a multi-system response to increased metabolic demands. Acquisition of extensive postcranial pneumaticity in small-bodied maniraptorans may indicate avian-like high-performance endothermy.", url = "https://doi.org/10.1111/j.1469-185x.2011.00190.x", doi = "10.1111/j.1469-185x.2011.00190.x", openalex = "W2003924744", references = "doi101002jez513, doi101002jmor10470, doi101002sici1097018520000215261125aidar630co27, doi101007s0011400804883, doi101007s001140090614x, doi101017s0094837300021308, doi101038nature07856, doi101073pnas0708903105, doi10108002724634199710011018, doi101086284325, doi101093auk12041206, doi101093bioinformaticsbtg412, doi101093sysbio41118, doi101098rstb19890106, doi101111j10963642200600245x, doi101111j10963642200900569x, doi101126science1180219, doi1012066481, doi101371journalpone0003303, doi101371journalpone0007390, doi10167102724634200727127tpasom20co2, doi1023071292217, doi1023071441916, doi105281zenodo16171435, doi105860choice392183, doi105860choice434677, doi105962bhltitle60562, openalexw2611511275, openalexw3086315876, ostrom2019osteology, owen1857monograph, owen2015monograph" } @article{doi101126science1198467, author = "Martínez, Ricardo N. and Sereno, Paul C. and Alcober, Oscar A. and Colombi, Carina E. and Renne, Paul R. and Montañez, Isabel P. and Currie, Brian S.", title = "A Basal Dinosaur from the Dawn of the Dinosaur Era in Southwestern Pangaea", year = "2011", journal = "Science", abstract = "Upper Triassic rocks in northwestern Argentina preserve the most complete record of dinosaurs before their rise to dominance in the Early Jurassic. Here, we describe a previously unidentified basal theropod, reassess its contemporary Eoraptor as a basal sauropodomorph, divide the faunal record of the Ischigualasto Formation with biozones, and bracket the formation with (40)Ar/(39)Ar ages. Some 230 million years ago in the Late Triassic (mid Carnian), the earliest dinosaurs were the dominant terrestrial carnivores and small herbivores in southwestern Pangaea. The extinction of nondinosaurian herbivores is sequential and is not linked to an increase in dinosaurian diversity, which weakens the predominant scenario for dinosaurian ascendancy as opportunistic replacement.", url = "https://doi.org/10.1126/science.1198467", doi = "10.1126/science.1198467", openalex = "W2025986670", references = "currie2009stratigraphy, doi101016jearscirev201004001, doi101016jgca201006017, doi101016jjsames200504002, doi101017s1477201907002040, doi101017s1477201907002271, doi101038361064a0, doi10108002724634199410011523, doi101080147720192010484650, doi101111j1469185x200900094x, doi101126science2605109794, doi101126science28454232137, doi101146annurevearth251435, nesbitt2009a, sereno1997the" } @article{doi1011861471214813208, author = "Jones, Marc E. H. and Anderson, Cajsa Lisa and Hipsley, Christy A. and Müller, Johannes and Evans, Susan E. and Schoch, Rainer R.", title = "Integration of molecules and new fossils supports a Triassic origin for Lepidosauria (lizards, snakes, and tuatara)", year = "2013", journal = "BMC Evolutionary Biology", abstract = "BACKGROUND: Lepidosauria (lizards, snakes, tuatara) is a globally distributed and ecologically important group of over 9,000 reptile species. The earliest fossil records are currently restricted to the Late Triassic and often dated to 227 million years ago (Mya). As these early records include taxa that are relatively derived in their morphology (e.g. Brachyrhinodon), an earlier unknown history of Lepidosauria is implied. However, molecular age estimates for Lepidosauria have been problematic; dates for the most recent common ancestor of all lepidosaurs range between approximately 226 and 289 Mya whereas estimates for crown-group Squamata (lizards and snakes) vary more dramatically: 179 to 294 Mya. This uncertainty restricts inferences regarding the patterns of diversification and evolution of Lepidosauria as a whole. RESULTS: Here we report on a rhynchocephalian fossil from the Middle Triassic of Germany (Vellberg) that represents the oldest known record of a lepidosaur from anywhere in the world. Reliably dated to 238-240 Mya, this material is about 12 million years older than previously known lepidosaur records and is older than some but not all molecular clock estimates for the origin of lepidosaurs. Using RAG1 sequence data from 76 extant taxa and the new fossil specimens two of several calibrations, we estimate that the most recent common ancestor of Lepidosauria lived at least 242 Mya (238-249.5), and crown-group Squamata originated around 193 Mya (176-213). CONCLUSION: A Early/Middle Triassic date for the origin of Lepidosauria disagrees with previous estimates deep within the Permian and suggests the group evolved as part of the faunal recovery after the end-Permain mass extinction as the climate became more humid. Our origin time for crown-group Squamata coincides with shifts towards warmer climates and dramatic changes in fauna and flora. Most major subclades within Squamata originated in the Cretaceous postdating major continental fragmentation. The Vellberg fossil locality is expected to become an important resource for providing a more balanced picture of the Triassic and for bridging gaps in the fossil record of several other major vertebrate groups.", url = "https://doi.org/10.1186/1471-2148-13-208", doi = "10.1186/1471-2148-13-208", openalex = "W2085365822", references = "doi101017cbo9780511536045, doi10103831927, doi101093bioinformaticsbtg180, doi101093molbevmsp259, doi101093oxfordjournalsmolbeva003974, doi101186147121487214, doi1012063521, doi101371journalpbio0040088, nesbitt2013the, openalexw1900040508, openalexw2733548038, openalexw2989049194" } @article{nesbitt2013the, author = "Nesbitt, Sterling J. and Barrett, Paul M. and Werning, Sarah and Sidor, Christian A. and Charig, Alan J.", title = "The oldest dinosaur? A Middle Triassic dinosauriform from Tanzania", year = "2013", journal = "Biology Letters", abstract = "The rise of dinosaurs was a major event in vertebrate history, but the timing of the origin and early diversification of the group remain poorly constrained. Here, we describe Nyasasaurus parringtoni gen. et sp. nov., which is identified as either the earliest known member of, or the sister–taxon to, Dinosauria. Nyasasaurus possesses a unique combination of dinosaur character states and an elevated growth rate similar to that of definitive early dinosaurs. It demonstrates that the initial dinosaur radiation occurred over a longer timescale than previously thought (possibly 15 Myr earlier), and that dinosaurs and their immediate relatives are better understood as part of a larger Middle Triassic archosauriform radiation. The African provenance of Nyasasaurus supports a southern Pangaean origin for Dinosauria.", url = "https://doi.org/10.1098/rsbl.2012.0949", doi = "10.1098/rsbl.2012.0949", number = "1", openalex = "W2099666527", pages = "20120949", volume = "9", references = "doi101016jearscirev201004001, doi101017s1477201906001970, doi101017s1477201907002271, doi101038nature08718, doi101111j1469185x200900094x, doi101111j1469185x201100190x, doi101126science1198467, doi101126science28454232137, doi1012063521, doi1016710272463420040240555gisdap20co2, doi1021131081135" } @article{doi101371journalpbio1001853, author = "Benson, Roger and Campione, Nicolás E. and Carrano, Matthew T. and Mannion, Philip D. and Sullivan, Corwin and Upchurch, Paul and Evans, David C.", title = "Rates of Dinosaur Body Mass Evolution Indicate 170 Million Years of Sustained Ecological Innovation on the Avian Stem Lineage", year = "2014", journal = "PLoS Biology", abstract = "Large-scale adaptive radiations might explain the runaway success of a minority of extant vertebrate clades. This hypothesis predicts, among other things, rapid rates of morphological evolution during the early history of major groups, as lineages invade disparate ecological niches. However, few studies of adaptive radiation have included deep time data, so the links between extant diversity and major extinct radiations are unclear. The intensively studied Mesozoic dinosaur record provides a model system for such investigation, representing an ecologically diverse group that dominated terrestrial ecosystems for 170 million years. Furthermore, with 10,000 species, extant dinosaurs (birds) are the most speciose living tetrapod clade. We assembled composite trees of 614-622 Mesozoic dinosaurs/birds, and a comprehensive body mass dataset using the scaling relationship of limb bone robustness. Maximum-likelihood modelling and the node height test reveal rapid evolutionary rates and a predominance of rapid shifts among size classes in early (Triassic) dinosaurs. This indicates an early burst niche-filling pattern and contrasts with previous studies that favoured gradualistic rates. Subsequently, rates declined in most lineages, which rarely exploited new ecological niches. However, feathered maniraptoran dinosaurs (including Mesozoic birds) sustained rapid evolution from at least the Middle Jurassic, suggesting that these taxa evaded the effects of niche saturation. This indicates that a long evolutionary history of continuing ecological innovation paved the way for a second great radiation of dinosaurs, in birds. We therefore demonstrate links between the predominantly extinct deep time adaptive radiation of non-avian dinosaurs and the phenomenal diversification of birds, via continuing rapid rates of evolution along the phylogenetic stem lineage. This raises the possibility that the uneven distribution of biodiversity results not just from large-scale extrapolation of the process of adaptive radiation in a few extant clades, but also from the maintenance of evolvability on vast time scales across the history of life, in key lineages.", url = "https://doi.org/10.1371/journal.pbio.1001853", doi = "10.1371/journal.pbio.1001853", openalex = "W2155522161", references = "doi101007b97636, doi101017s009483730001263x, doi101017s009483730001280x, doi10103835086500, doi10103844766, doi101038nature11631, doi10108010635150490445706, doi101086284325, doi101093bioinformaticsbtm538, doi101093oso97801985052350010001, doi101093oso97801985404720010001, doi101098rspb20122526, doi101111j001438202003tb00285x, doi101111j1469185x201000137x, doi101111j15585646201201723x, doi101126science1144066, doi101126science1161833, doi101146annurevecolsys39110707173447, doi101159000452856, doi101186174170071060, doi101198tech2003s146, doi101371journalpbio1001853, doi101371journalpone0007390, doi101371journalpone0044318, doi10166612041, martinsander2006bone, openalexw2145250129" } @article{doi101073pnas1512541112, author = "Marsicano, Claudia A. and Irmis, Randall B. and Mancuso, Adriana Cecilia and Mundil, Roland and Chemale, Farid", title = "The precise temporal calibration of dinosaur origins", year = "2015", journal = "Proceedings of the National Academy of Sciences", abstract = "Dinosaurs have been major components of ecosystems for over 200 million years. Although different macroevolutionary scenarios exist to explain the Triassic origin and subsequent rise to dominance of dinosaurs and their closest relatives (dinosauromorphs), all lack critical support from a precise biostratigraphically independent temporal framework. The absence of robust geochronologic age control for comparing alternative scenarios makes it impossible to determine if observed faunal differences vary across time, space, or a combination of both. To better constrain the origin of dinosaurs, we produced radioisotopic ages for the Argentinian Chañares Formation, which preserves a quintessential assemblage of dinosaurian precursors (early dinosauromorphs) just before the first dinosaurs. Our new high-precision chemical abrasion thermal ionization mass spectrometry (CA-TIMS) U-Pb zircon ages reveal that the assemblage is early Carnian (early Late Triassic), 5- to 10-Ma younger than previously thought. Combined with other geochronologic data from the same basin, we constrain the rate of dinosaur origins, demonstrating their relatively rapid origin in a less than 5-Ma interval, thus halving the temporal gap between assemblages containing only dinosaur precursors and those with early dinosaurs. After their origin, dinosaurs only gradually dominated mid- to high-latitude terrestrial ecosystems millions of years later, closer to the Triassic-Jurassic boundary.", url = "https://doi.org/10.1073/pnas.1512541112", doi = "10.1073/pnas.1512541112", openalex = "W2196133811", references = "doi101016jcub201311063, doi101016jearscirev201004001, doi101016jepsl201107015, doi101016jgeobios200304008, doi101017s0094837300010575, doi101017s1755691013000431, doi101038nature08718, doi101073pnas1302323110, doi101073pnas1402369111, doi101073pnas1505252112, doi101111j1469185x200900094x, doi101126science1065522, doi101126science1180350, doi101126science1198467, doi101126science2605109794, doi101144sp3799, nesbitt2009a, nesbitt2013the, openalexw2113837685" } @article{doi101016jcub201609040, author = "Cabreira, Sérgio Furtado and Kellner, Alexander W. A. and Dias‐da‐Silva, Sérgio and da Silva, Lúcio Roberto and Bronzati, Mario and Marsola, Júlio C. A. and Müller, Rodrigo Temp and Bittencourt, Jonathas S. and Batista, Brunna Jul’Armando Rezende and Raugust, Tiago and Carrilho, Rodrigo and Brodt, André and Langer, Max C.", title = "A Unique Late Triassic Dinosauromorph Assemblage Reveals Dinosaur Ancestral Anatomy and Diet", year = "2016", journal = "Current Biology", url = "https://doi.org/10.1016/j.cub.2016.09.040", doi = "10.1016/j.cub.2016.09.040", openalex = "W2549642838", references = "crossref1998encyclopedia, doi101016jcub201311063, doi101016jearscirev201004001, doi101017s1477201906001970, doi101073pnas1011924108, doi10108002724634199110011426, doi101080027246342013818546, doi101080027246342013820113, doi101080147720192010484650, doi101126science1143325, doi101144sp3799, doi1012063521, doi1016710390290218, doi101671a1097, doi105281zenodo16171435, doi107717peerj1778" } @article{doi101016jjop201711004, author = "Xing, Lida and Ba, Jin and Lockley, Martin G. and Klein, Hendrik and Yan, Sheng-Wu and Romilio, Anthony and Chou, Chunyong and Persons, W. Scott", title = "Late Triassic sauropodomorph and Middle Jurassic theropod tracks from the Xichang Basin, Sichuan Province, southwestern China: First report of the ichnogenus Carmelopodus", year = "2017", journal = "Journal of Palaeogeography", abstract = "Upper Triassic and Middle Jurassic strata of the Xichang Basin in Sichuan Province, southwestern China, yielded important dinosaur ichnofossils. From the Xujiahe Formation of the Yiguojiao tracksite, we report a Late Triassic footprint assemblage in China and the first discovery of diagnostic Triassic sauropodomorph tracks in this region. The tracks share a number of features in common with the ichnogenera Eosauropus (Late Triassic) and Liujianpus (Early Jurassic). The neighboring Bingtu tracksite is stratigraphically younger (Shaximiao Formation, Middle Jurassic) and preserves small tridactyl theropod tracks that represent the first occurrence of the ichnotaxon Carmelopodus in China and Asia. While these tracks are morphologically comparable to those from the Middle Jurassic type locality in North America, the specimens from China show the proximal margin of the digit IV impression in a more cranial position, which may indicate a trackmaker with a relatively short metatarsal IV. In addition to the skeletal record, the Carmelopodus footprints document the presence of small theropods in the dinosaur fauna of the Middle Jurassic Shaximiao Formation.", url = "https://doi.org/10.1016/j.jop.2017.11.004", doi = "10.1016/j.jop.2017.11.004", openalex = "W2768452499", references = "doi101016jcretres200510009, doi101038261129a0, doi10108010420940390257914, doi10108010420940490442296, doi1011111755672412026, doi104202app003742017, doi105962bhltitle70405, doi10718895fylantbak30809522, lull1915triassic, openalexw2149387945, openalexw2619609965, openalexw3147398959" } @article{doi101038nature22037, author = "Nesbitt, Sterling J. and Butler, Richard J. and Ezcurra, Martín D. and Barrett, Paul M. and Stocker, Michelle R. and Angielczyk, Kenneth D. and Smith, Roger M. H. and Sidor, Christian A. and Niedźwiedzki, Grzegorz and Сенников, А. Г. and Charig, Alan J.", title = "The earliest bird-line archosaurs and the assembly of the dinosaur body plan", year = "2017", journal = "Nature", abstract = "The relationship between dinosaurs and other reptiles is well established, but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies. The closest extinct relatives of dinosaurs either have highly derived morphologies or are known from poorly preserved or incomplete material. Here we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch. The anatomy of T. rhadinus provides key information that unites several enigmatic taxa from across Pangaea into a previously unrecognized clade, Aphanosauria. This clade is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia. We demonstrate that several anatomical features long thought to characterize Dinosauria and dinosauriforms evolved much earlier, soon after the bird-crocodylian split, and that the earliest avemetatarsalians retained the crocodylian-like ankle morphology and hindlimb proportions of stem archosaurs and early pseudosuchians. Early avemetatarsalians were substantially more species-rich, widely geographically distributed and morphologically diverse than previously recognized. Moreover, several early dinosauromorphs that were previously used as models to understand dinosaur origins may represent specialized forms rather than the ancestral avemetatarsalian morphology.", url = "https://doi.org/10.1038/nature22037", doi = "10.1038/nature22037", openalex = "W2606337068", references = "doi1010160169534789901626, doi10108002724634199110011426, doi101080027246342013820113, doi101111bij12746, doi101111cla12160, doi101111j10960031200800217x, doi101111j136530911989tb00817x, doi101111j1469185x200900094x, doi101126science1161833, doi101126science28454232137, doi1012060003009020073021taoeoa20co2, doi1012063521, doi1016710272463420040240555gisdap20co2, doi1023071005355, doi105281zenodo16171435, doi107717peerj1778, nesbitt2013the" } @article{doi1010801477201920171352623, author = "Agnolín, Federico L. and Rozadilla, Sebastián", title = "Phylogenetic reassessment of Pisanosaurus mertii Casamiquela, 1967, a basal dinosauriform from the Late Triassic of Argentina", year = "2017", journal = "Journal of Systematic Palaeontology", abstract = "Pisanosaurus mertii was originally described on the basis of an incomplete skeleton from the early Late Triassic (Carnian) of northern Argentina. It is consistently regarded by most authors as a very basal ornithischian, the sister group of remaining members of the clade. The referral to Ornithischia is based mainly on tooth-bearing bones and tooth morphology. On the other hand, the postcranium is recognized as strikingly plesiomorphic for ornithischians, and even for dinosaurs. The recent description of non-dinosaurian dinosauriforms of the clade Silesauridae having ornithischian-like dentition invites a review of the phylogenetic affinities of Pisanosaurus. In this regard, an overview of the holotype specimen allows a reanalysis of previous anatomical interpretations of this taxon. The phylogenetic analysis presented here suggests that Pisanosaurus may be better interpreted as a member of the non-dinosaurian Silesauridae. It shares with silesaurids reduced denticles on the teeth, teeth fused to maxilla and dentary bone, sacral ribs shared between two sacral vertebrae, lateral side of proximal tibia with a fibular flange, and dorsoventrally flattened pedal ungual phalanges. The present analysis indicates that Pisanosaurus should be removed from the base of the Ornithischia and should no longer be considered the oldest representative of this dinosaurian clade.", url = "https://doi.org/10.1080/14772019.2017.1352623", doi = "10.1080/14772019.2017.1352623", openalex = "W2742303876", references = "doi101017s1755691013000431, doi101098rstb19740001, doi105281zenodo16673433, doi107717peerj1523" } @article{doi104202app003742017, author = "Lallensack, Jens N. and Klein, Hendrik and Milàn, Jesper and Wings, Oliver and Mateus, Octávio and Clemmensen, Lars B.", title = "Sauropodomorph dinosaur trackways from the Fleming Fjord Formation of East Greenland: evidence for Late Triassic sauropods", year = "2017", journal = "Acta Palaeontologica Polonica", abstract = "The Late Triassic (Norian-early Rhaetian) Fleming Fjord Formation of central East Greenland preserves a diverse fossil fauna, including both body and trace fossils. Trackways of large quadrupedal archosaurs, although already reported in 1994 and mentioned in subsequent publications, are here described and figured in detail for the first time, based on photogrammetric data collected during fieldwork in 2012. Two trackways can be referred to Eosauropus, while a third, bipedal trackway may be referred to Evazoum, both of which have been considered to represent sauropodomorph dinosaur tracks. Both the Evazoum and the Eosauropus trackways are distinctly larger than other trackways referred to the respective ichnogenera. The trackmaker of the best preserved Eosauropus trackway is constrained using a synapomorphy-based approach. The quadrupedal posture, the entaxonic pes structure, and five weight-bearing digits indicate a derived sauropodiform trackmaker. Other features exhibited by the tracks, including the semi-digitigrade pes and the laterally deflected unguals, are commonly considered synapomorphies of more exclusive clades within Sauropoda. The present trackway documents an early acquisition of a eusauropod-like pes anatomy while retaining a well-developed claw on pedal digit IV, which is reduced in eusauropods. Although unequivocal evidence for sauropod dinosaurs is no older than the Early Jurassic, the present trackway provides evidence for a possible Triassic origin of the group.", url = "https://doi.org/10.4202/app.00374.2017", doi = "10.4202/app.00374.2017", openalex = "W2750743522", references = "doi1034194bullgguv1396681" } @article{doi101038s41598020678541, author = "Desojo, Julia B. and Fiorelli, Lucas E. and Ezcurra, Martín D. and Martinelli, Agustín G. and Ramezani, Jahandar and da Rosa, Átila Augusto Stock and von Baczko, M. Belén and Trotteyn, M. Jimena and Montefeltro, Felipe C. and Ezpeleta, Miguel and Langer, Max C.", title = "The Late Triassic Ischigualasto Formation at Cerro Las Lajas (La Rioja, Argentina): fossil tetrapods, high-resolution chronostratigraphy, and faunal correlations", year = "2020", journal = "Scientific Reports", abstract = "Present knowledge of Late Triassic tetrapod evolution, including the rise of dinosaurs, relies heavily on the fossil-rich continental deposits of South America, their precise depositional histories and correlations. We report on an extended succession of the Ischigualasto Formation exposed in the Hoyada del Cerro Las Lajas (La Rioja, Argentina), where more than 100 tetrapod fossils were newly collected, augmented by historical finds such as the ornithosuchid Venaticosuchus rusconii and the putative ornithischian Pisanosaurus mertii. Detailed lithostratigraphy combined with high-precision U-Pb geochronology from three intercalated tuffs are used to construct a robust Bayesian age model for the formation, constraining its deposition between 230.2 ± 1.9 Ma and 221.4 ± 1.2 Ma, and its fossil-bearing interval to 229.20 + 0.11/- 0.15-226.85 + 1.45/- 2.01 Ma. The latter is divided into a lower Hyperodapedon and an upper Teyumbaita biozones, based on the ranges of the eponymous rhynchosaurs, allowing biostratigraphic correlations to elsewhere in the Ischigualasto-Villa Unión Basin, as well as to the Paraná Basin in Brazil. The temporally calibrated Ischigualasto biostratigraphy suggests the persistence of rhynchosaur-dominated faunas into the earliest Norian. Our ca. 229 Ma age assignment to Pi. mertii partially fills the ghost lineage between younger ornithischian records and the oldest known saurischians at ca. 233 Ma.", url = "https://doi.org/10.1038/s41598-020-67854-1", doi = "10.1038/s41598-020-67854-1", openalex = "W3045879460", references = "doi101016c20090644421, doi101016jgr201801005, doi101016jquascirev200807009, doi101016s0753396900800026, doi101017cbo9780511612381, doi101017s1755691013000431, doi101038nature22037, doi101073pnas1402369111, doi101080027246342013818546, doi101080027246342013820113, doi101080031155182015994114, doi101098rstb19740001, doi101111j109600311988tb00514x, doi101111j10963642200900631x, doi101111j14679876200800623x, doi101126science1198467, doi101144sp37916, doi1012063521, doi1018814epiiugs2013v36i3002, doi1023071005355, doi1023072413376, doi107717peerj1778" } @article{doi101111pala12514, author = "Dunne, Emma M. and Farnsworth, Alexander and Greene, Sarah E. and Lunt, Daniel J. and Butler, Richard J.", title = "Climatic drivers of latitudinal variation in Late Triassic tetrapod diversity", year = "2020", journal = "Palaeontology", abstract = "Abstract The latitudinal biodiversity gradient (LBG), the increase in biodiversity from the poles to the equator, is one of the most widely recognized global macroecological patterns, yet its deep time evolution and drivers remain uncertain. The Late Triassic (237–201 Ma), a critical interval for the early evolution and radiation of modern tetrapod groups (e.g. crocodylomorphs, dinosaurs, mammaliamorphs), offers a unique opportunity to explore the palaeolatitudinal patterns of tetrapod diversity since it is extensively sampled spatially when compared with other pre‐Cenozoic intervals, particularly at lower palaeolatitudes. Here, we explore palaeolatitudinal patterns of Late Triassic tetrapod diversity by applying sampling standardization to comprehensive occurrence data from the Paleobiology Database (PBDB). We then use palaeoclimatic model simulations to explore the palaeoclimatic ranges occupied by major tetrapod groups, allowing insight into the influence of palaeoclimate on the palaeolatitudinal distribution of these groups. Our results show that Late Triassic tetrapods generally do not conform to a modern‐type LBG; instead, sampling‐standardized species richness is highest at mid‐palaeolatitudes. In contrast, the richness of pseudosuchians (crocodylians and their relatives) is highest at the palaeoequator, a pattern that is retained throughout their subsequent evolutionary history. Pseudosuchians generally occupied a more restricted range of palaeoclimatic conditions than other tetrapod groups, a condition analogous to modern day reptilian ectotherms, while avemetatarsalians (the archosaur group containing dinosaurs and pterosaurs) exhibit comparatively wider ranges, which is more similar to modern endotherms, such as birds and mammals, suggesting important implications for the evolution of thermal physiology in dinosaurs.", url = "https://doi.org/10.1111/pala.12514", doi = "10.1111/pala.12514", openalex = "W3100536757", references = "doi1010160165176580900245, doi101038ncomms14845, doi101038ncomms9296, doi101038s41467019089972, doi1010719781486300679, doi101080147720192014960486, doi101086381004, doi101093biomet4034237, doi101093biomet762297, doi1011112041210x12613, doi101111j14610248200701020x, doi101126science1130880, doi101146annurevecolsys34012103144032, openalexw3086315876" } @article{doi101126sciadvaba0099, author = "Corso, Jacopo Dal and Bernardi, Massimo and Sun, Yadong and Song, Haijun and Seyfullah, Leyla J. and Preto, Nereo and Gianolla, Piero and Ruffell, Alastair and Kustatscher, Evelyn and Roghi, Guido and Merico, Agostino and Hohn, Sönke and Schmidt, Alexander R. and Marzoli, Andrea and Newton, Robert J. and Wignall, Paul B. and Benton, Michael J.", title = "Extinction and dawn of the modern world in the Carnian (Late Triassic)", year = "2020", journal = "Science Advances", abstract = "The Carnian Pluvial Episode (Late Triassic) was a time of global environmental changes and possibly substantial coeval volcanism. The extent of the biological turnover in marine and terrestrial ecosystems is not well understood. Here, we present a meta-analysis of fossil data that suggests a substantial reduction in generic and species richness and the disappearance of 33\% of marine genera. This crisis triggered major radiations. In the sea, the rise of the first scleractinian reefs and rock-forming calcareous nannofossils points to substantial changes in ocean chemistry. On land, there were major diversifications and originations of conifers, insects, dinosaurs, crocodiles, lizards, turtles, and mammals. Although there is uncertainty on the precise age of some of the recorded biological changes, these observations indicate that the Carnian Pluvial Episode was linked to a major extinction event and might have been the trigger of the spectacular radiation of many key groups that dominate modern ecosystems.", url = "https://doi.org/10.1126/sciadv.aba0099", doi = "10.1126/sciadv.aba0099", openalex = "W3044243879", references = "doi10100797836427963404, doi101016jearscirev201305014, doi101016jgr201801005, doi101016jjsames200504002, doi101016jpalaeo200911006, doi101016jpalaeo201611005, doi101016s0012825202001046, doi101038nature07533, doi101038nature22037, doi101038s41467018039961, doi101038s4155901703055, doi101073pnas1512541112, doi101093icbicq078, doi101111brv12161, doi101111j1469185x200900094x, doi101126science1095964, doi101126science1198467, doi101126science1211028, doi1011300016760619961080195gcgbpt23co2, doi1011300091761319890170265soccae23co2, doi101144gsjgs14720321, doi101146annurevearth33092203122654, doi1011861471214813208" } @article{barta2022osteohistology, author = "Barta, Daniel E. and Griffin, Christopher T. and Norell, Mark A.", title = "Osteohistology of a Triassic dinosaur population reveals highly variable growth trajectories typified early dinosaur ontogeny", year = "2022", journal = "Scientific Reports", abstract = "Intraspecific variation in growth trajectories provides a fundamental source of variation upon which natural selection acts. Recent work hints that early dinosaurs possessed elevated levels of such variation compared to other archosaurs, but comprehensive data uniting body size, bone histology, and morphological variation from a stratigraphically constrained early dinosaur population are needed to test this hypothesis. The Triassic theropod Coelophysis bauri, known from a bonebed preserving a single population of coeval individuals, provides an exceptional system to assess whether highly variable growth patterns were present near the origin of Dinosauria. Twenty-four histologically sampled individuals were less than a year to at least four years old and confirm the right-skewed age distribution of the Coelophysis assemblage. Poor correlations among size, age, and morphological maturity strongly support the presence of unique, highly variable growth trajectories in early dinosaurs relative to coeval archosaurs and their living kin.", url = "https://doi.org/10.1038/s41598-022-22216-x", doi = "10.1038/s41598-022-22216-x", number = "1", openalex = "W4306291770", volume = "12", references = "doi1010079783319242774, doi101016jtree200508012, doi101017s0094837300021308, doi10103835086558, doi101038nmeth2019, doi101038nmeth2089, doi1010719781486300679, doi10108002724634199610011283, doi101093oso97801985774160010001, doi101201b21296" } @article{falkingham2022late, author = "Falkingham, Peter L. and Maidment, Susannah C. R. and Lallensack, Jens N. and Martin, Jeremy E. and Suan, Guillaume and Cherns, Lesley and Howells, Cindy and Barrett, Paul M.", title = "Late Triassic dinosaur tracks from Penarth, south Wales", year = "2022", journal = "Geological Magazine", abstract = "Evidence of Late Triassic large tetrapods from the UK is rare. Here, we describe a track-bearing surface located on the shoreline near Penarth, south Wales, United Kingdom. The total exposed surface is c. 50 m long and c. 2 m wide, and is split into northern and southern sections by a small fault. We interpret these impressions as tracks, rather than abiogenic sedimentary structures, because of the possession of marked displacement rims and their relationship to each other with regularly spaced impressions forming putative trackways. The impressions are large (up to c. 50 cm in length), but poorly preserved, and retain little information about track-maker anatomy. We discuss alternative, plausible, abiotic mechanisms that might have been responsible for the formation of these features, but reject them in favour of these impressions being tetrapod tracks. We propose that the site is an additional occurrence of the ichnotaxon Eosauropus, representing a sauropodomorph trackmaker, thereby adding a useful new datum to their sparse Late Triassic record in the UK. We also used historical photogrammetry to digitally map the extent of site erosion during 2009–2020. More than 1 m of the surface exposure has been lost over this 11-year period, and the few tracks present in both models show significant smoothing, breakage and loss of detail. These tracks are an important datapoint for Late Triassic palaeontology in the UK, even if they cannot be confidently assigned to a specific trackmaker. The documented loss of the bedding surface highlights the transient and vulnerable nature of our fossil resources, particularly in coastal settings, and the need to gather data as quickly and effectively as possible.", url = "https://doi.org/10.1017/s0016756821001308", doi = "10.1017/s0016756821001308", number = "6", pages = "821-832", volume = "159" } @article{doi101144jgs2023003, author = "Edgar, Kirsty M. and Haller, Lewis and Cashmore, Daniel D. and Dunne, Emma M. and Butler, Richard J.", title = "Stratigraphic and geographic distribution of dinosaur tracks in the UK", year = "2023", journal = "Journal of the Geological Society", abstract = "Dinosaur tracks are a key means of determining the palaeoecology and distribution of dinosaurs through time. They provide an information source that is highly complementary to the body (skeletal) fossil record, but differ in preserving direct evidence of the animals’ interactions with their environment. The UK has a rich history of c. 200 years of dinosaur track discovery, but no recent synthesis exists. Here, we present a new dataset of dinosaur tracks in the UK. This dataset shows a close correlation between the distribution of terrestrial sediments and the preservation of dinosaur tracks through the Mesozoic, providing discrete snapshots into dinosaur communities in the Late Triassic, Mid-Jurassic and Early Cretaceous. The dinosaur track record shows similar broad patterns of diversity and relative abundance of the major dinosaur groups (Theropoda, Sauropodomorpha, Ornithopoda and Thyreophora) through time to the body fossil record, although it differs in that body fossils are also found (albeit infrequently) in marine sediments. There is a broad trend towards higher numbers of track occurrences through time and a notable increase in the relative abundance of ornithopod tracks following the Jurassic–Cretaceous boundary. The track record remains an underutilized resource with the potential to provide a much fuller view of Mesozoic dinosaur ecosystems. Supplementary material: Our new UK dinosaur track database, the PBDB body fossil record and the relative abundance of non-marine/marine rocks in England and Wales used in this study are provided in Supplementary Tables 1–3, respectively, the R-code used to analyse the data and generate Figures 2 and 3 and Supplementary Figures 1–4 is given in Supplementary Information 1 and 2, and are available at https://doi.org/10.6084/m9.figshare.c.6606634", url = "https://doi.org/10.1144/jgs2023-003", doi = "10.1144/jgs2023-003", openalex = "W4367316070", references = "falkingham2022late" } @article{doi101016jjsames2024104977, author = "Corecco, Leonardo and Kohn, Matthew J. and Schultz, César Leandro", title = "Triassic climate and the rise of the dinosaur empire in South America", year = "2024", journal = "Journal of South American Earth Sciences", url = "https://doi.org/10.1016/j.jsames.2024.104977", doi = "10.1016/j.jsames.2024.104977", openalex = "W4399375734", references = "doi101038s41467024468432, doi101371journalpone0298242" } @article{doi101016jpgeola202405001, author = "Evans, Owain and Duffin, Christopher J. and Hildebrandt, Claudia and Benton, Michael J.", title = "Microvertebrates from the basal Rhaetian Bone Bed (Late Triassic) at Lavernock, South Wales", year = "2024", journal = "Proceedings of the Geologists Association", abstract = "The cliff and foreshore sections at Lavernock, South Wales form the type section of the Penarth Group, representing the Rhaetian stage in the UK, the latest Triassic. The Rhaetian bonebeds here have been famous for over 150 years for their vertebrate fossils. Here, we show that, unusually, the Lavernock basal Westbury Formation bonebed is dominated by osteichthyan teeth, with sharks such as Lissodus relatively rare. The rounded teeth of the durophagous bony fish Sargodon are abundant, with teeth of Severnichthys next in abundance, and Gyrolepis the rarest, quite unlike most other Rhaetian bone beds. Also, small elements such as shark denticles have not been found, whilst larger bones of marine reptiles (ichthyosaurs, plesiosaurs) and dinosaurs do occur. The dinosaur bones are unusual, and Lavernock may have yielded more such bones than any other British Rhaetian bone bed. These terrestrial elements suggest that the lower bone bed accumulated close to shore, but underwent considerable transport, with clasts perhaps moving back and forwards, to explain the abrasion of specimens, the larger elements and absence of smaller specimens. Dinosaurs are more widely documented in the Late Triassic of the Penarth area, around Lavernock, than anywhere else in the UK.", url = "https://doi.org/10.1016/j.pgeola.2024.05.001", doi = "10.1016/j.pgeola.2024.05.001", openalex = "W4398247248", references = "falkingham2022late" } @article{doi101371journalpone0298242, author = "Rogers, Kristina Curry and Martínez, Ricardo N. and Colombi, Carina E. and Rogers, Raymond R. and Alcober, Oscar A.", title = "Osteohistological insight into the growth dynamics of early dinosaurs and their contemporaries", year = "2024", journal = "PLoS ONE", abstract = "Dinosauria debuted on Earth's stage in the aftermath of the Permo-Triassic Mass Extinction Event, and survived two other Triassic extinction intervals to eventually dominate terrestrial ecosystems. More than 231 million years ago, in the Upper Triassic Ischigualasto Formation of west-central Argentina, dinosaurs were just getting warmed up. At this time, dinosaurs represented a minor fraction of ecosystem diversity. Members of other tetrapod clades, including synapsids and pseudosuchians, shared convergently evolved features related to locomotion, feeding, respiration, and metabolism and could have risen to later dominance. However, it was Dinosauria that radiated in the later Mesozoic most significantly in terms of body size, diversity, and global distribution. Elevated growth rates are one of the adaptations that set later Mesozoic dinosaurs apart, particularly from their contemporary crocodilian and mammalian compatriots. When did the elevated growth rates of dinosaurs first evolve? How did the growth strategies of the earliest known dinosaurs compare with those of other tetrapods in their ecosystems? We studied femoral bone histology of an array of early dinosaurs alongside that of non-dinosaurian contemporaries from the Ischigualasto Formation in order to test whether the oldest known dinosaurs exhibited novel growth strategies. Our results indicate that the Ischigualasto vertebrate fauna collectively exhibits relatively high growth rates. Dinosaurs are among the fastest growing taxa in the sample, but they occupied this niche alongside crocodylomorphs, archosauriformes, and large-bodied pseudosuchians. Interestingly, these dinosaurs grew at least as quickly, but more continuously than sauropodomorph and theropod dinosaurs of the later Mesozoic. These data suggest that, while elevated growth rates were ancestral for Dinosauria and likely played a significant role in dinosaurs' ascent within Mesozoic ecosystems, they did not set them apart from their contemporaries.", url = "https://doi.org/10.1371/journal.pone.0298242", doi = "10.1371/journal.pone.0298242", openalex = "W4393900212", references = "barta2022osteohistology, doi1010079781489953919, doi101016s1631069102014294, doi101017s0094837300021308, doi101038361064a0, doi10108002724634199610011283, doi101111j1469185x200900094x, doi101111j1469185x201000137x, doi101111joa13937, doi101126science1161833, doi101126science1198467, doi101126scienceadc8714, doi10167102724634200727350asoitp20co2" } @article{doi10159000013765202420231248, author = "Müller, Rodrigo Temp and Damke, Lísie Vitória Soares and Terras, Rafael", title = "Skeletally immature individuals nest together in the phylogenetic tree of early dinosaurs", year = "2024", journal = "Anais da Academia Brasileira de Ciências", abstract = "The phylogenetic affinities of early dinosaurs are a controversial topic. There are disputing scenarios aiming to explain the evolutionary tree of these reptiles. A number of factors play a role on this issue. High levels of intraspecific variation experienced by the earliest forms are pointed by distinct authors as one of the main sources of phylogenetic biases. In the present study, we performed experimental analyses incorporating skeletally immature individuals as distinct operational taxonomic units in order to investigate the effect of ontogeny on the phylogeny and morphospace of early Late Triassic sauropodomorphs. The results support an “artificial” grouping of skeletally immature individuals of early dinosaurs in the phylogenetic trees, which is controlled by ontogenetic development. Such results are interpreted as the effect of ontogenetic control on the states of certain morphological characters, producing false synapomorphies. In addition, the morphological disparity analysis indicated a significant difference between the skeletally immature and mature individuals, corroborating previous assumptions. At this point, we suggest caution during the scoring process of early dinosaurs. Some approaches that avoid ontogenetically sensitive characters revealed a putative solution. Nevertheless, additional specimens and alternative tools are mandatory in order to properly deal with this issue.", url = "https://doi.org/10.1590/0001-3765202420231248", doi = "10.1590/0001-3765202420231248", openalex = "W4400888092", references = "barta2022osteohistology, doi101016jearscirev201004001, doi101016s0037073802003974, doi101038nature21700, doi10108010635150290102339, doi10108010635150590906037, doi101111j10960031200800209x, doi101111j109636422001tb01314x, doi101111j1469185x200900094x, doi101126science1198467, doi1012063521" } @article{doi101002ar25677, author = "Tolchard, Frederick and Perkins, B. and Nesbitt, Sterling J.", title = "Silesaurid (Archosauria: Dinosauriformes) remains from the base of the Dockum Group (Late Triassic: Otischalkian) of Texas provide new insights to the North American record of dinosauriforms", year = "2025", journal = "The Anatomical Record", abstract = "Silesaurids (Archosauria: Dinosauriformes) are found in Middle to Upper Triassic deposits across Pangea, but few stratigraphic sections record the evolution of the group in one geographic area over millions of years. Here, we describe silesaurid remains from the oldest of the Upper Triassic stratigraphic sequence from the base of the Dockum Group, from the type locality of the Otischalkian faunachronozone. Isolated limb bones diagnostic of silesaurids include humeri, femora, and tibiae of a seemingly unique Silesaurus-like taxon from the same locality (Otis Chalk Quarry 3). The femora consist of four specimens of different lengths that sample the variation of character states associated with ontogeny, also sampled previously in both silesaurids (e.g., Asilisaurus kongwe and Silesaurus opolensis) and within neotheropods within Dinosauria (e.g., Coelophysis bauri). Our observations of the variation in the silesaurid sample further reinforce the interpretation of high variation of morphological features common in dinosauriforms. Furthermore, we show that overpreparation of bone surfaces has hidden some of this variation in previous interpretations. The tibia growth series shows that the fibular crest of the tibia develops during ontogeny, yet another phylogenetically informative character for dinosaurs and their kin that is at least ontogenetically variable in silesaurids. The presence of silesaurids at the base of the Dockum Group (late Carnian or early Norian) conclusively shows that the group was present near the onset of deposition of Upper Triassic rocks and survived for millions of years in the same geographic area at low latitudes throughout the Late Triassic.", url = "https://doi.org/10.1002/ar.25677", doi = "10.1002/ar.25677", openalex = "W4410190660", references = "doi1010800891296320171333609, doi10159000013765202420231248" } @article{doi101016jcub202412053, author = "Heath, Joel A and Cooper, Natalie and Upchurch, Paul and Mannion, Philip D.", title = "Accounting for sampling heterogeneity suggests a low paleolatitude origin for dinosaurs", year = "2025", journal = "Current Biology", abstract = "Dinosaurs dominated Mesozoic terrestrial ecosystems for ∼160 million years, but their biogeographic origin remains poorly understood. The earliest unequivocal dinosaur fossils appear in the Carnian (∼230 Ma) of southern South America and Africa, leading most authors to propose southwestern Gondwana as the likely center of origin. However, the high taxonomic and morphological diversity of these earliest assemblages suggests a more ancient evolutionary history that is currently unsampled. Phylogenetic uncertainty at the base of Dinosauria, combined with the subsequent appearance of dinosaurs throughout Laurasia in their early evolutionary history, further complicates this picture. Here, we estimate the distribution of early dinosaurs and their archosaurian relatives under a phylogenetic maximum likelihood framework, testing alternative topological arrangements and incorporating potential abiotic barriers to dispersal into our biogeographic models. For the first time, we include spatiotemporal sampling heterogeneity in these models, which frequently supports a low-latitude Gondwanan origin for dinosaurs. These results are best supported when silesaurids are constrained as early-diverging ornithischians, which is likely because this topology accounts for the otherwise substantial ornithischian ghost lineage, explaining the group's absence from the fossil record prior to the Early Jurassic. Our results suggest that the archosaur radiation also took place within low-latitude Gondwana following the end-Permian extinction before lineages dispersed across Pangaea into ecologically and climatically distinct provinces during the Late Triassic. Mesozoic terrestrial vertebrates are under-sampled at low paleolatitudes, and our findings suggest that heterogeneous sampling has hitherto obscured the true paleobiogeographic origin of dinosaurs and their kin.", url = "https://doi.org/10.1016/j.cub.2024.12.053", doi = "10.1016/j.cub.2024.12.053", openalex = "W4406758949", references = "doi101016jjsames2021103341, doi101016jpgeola202307002, doi101038s4158602205133x, doi101073pnas1319091111, doi101093bioinformaticsbty633, doi101093sysbio461195, doi101093sysbiosys029, doi101093sysbiosyt040, doi101093sysbiosyu056, doi101109tac19741100705, doi101111j2041210x201100169x, doi1021425f55419694, doi1023073802723" } @article{doi101016jpgeola202412003, author = "Edgar, Kirsty M. and Butler, Richard J. and Larwood, Jonathan G. and Smith, Joshua J.P.", title = "Determining the relative scientific and cultural “value” of the UK's in-situ dinosaur track sites", year = "2025", journal = "Proceedings of the Geologists Association", abstract = "Dinosaur tracks (footprints) provide useful information on the palaeoecology and distribution of dinosaurs over time, complementing the skeletal (body) fossil record. These tracks are amongst the most popular and recognisable trace fossils in the natural world, attracting significant public interest and drawing visitors to sites in England, Scotland, and Wales. Beyond their scientific importance, they offer valuable aesthetic and educational opportunities in the tourism and education sectors. However, the protection, monitoring, communication, and scientific understanding of these sites vary widely. Here we review the nature of the fourteen in-situ dinosaur track sites present in the UK today, and subsequently use an established quantitative system to determine the relative scientific and cultural ‘value’ of each site. We find that the relative scientific and cultural value of UK track sites varies considerably, and that the two value types do not correlate with one another. UK sites with considerable national and international scientific value include the Late Triassic dinosaur track site Bendrick Rock, in South Wales, and the Middle Jurassic site Ardley Quarry, in Oxfordshire. By contrast, the Early Cretaceous dinosaur track sites at Hanover Point, Isle of Wight, and Spyway Quarry, Dorset have relatively high cultural value due to their accessibility and visitor appeal, but modest scientific value. This assessment helps identify threats and opportunities for UK dinosaur track sites, guiding future conservation, scientific research, and public engagement efforts.", url = "https://doi.org/10.1016/j.pgeola.2024.12.003", doi = "10.1016/j.pgeola.2024.12.003", openalex = "W4406510596", references = "falkingham2022late" } @article{doi1010800891296320252537165, author = "Abbassi, Nasrollah and Gharehbaghi, Arash and Maleki, Saeed", title = "New record of Late Triassic dinosaur tracks from the Shemshak Group of Alborz Mountains, Firuzkuh area, North Iran", year = "2025", journal = "Historical Biology", url = "https://doi.org/10.1080/08912963.2025.2537165", doi = "10.1080/08912963.2025.2537165", openalex = "W4412883584", references = "doi101016jgeobios202505004, falkingham2022late" } @article{doi101098rsbl20240474, author = "Chapelle, Kimberley E. J. and Griffin, Christopher T. and Pol, Diego", title = "Growing with dinosaurs: a review of dinosaur reproduction and ontogeny", year = "2025", journal = "Biology Letters", abstract = "Since the start of the twenty-first century, there has been a notable increase in annual publications focusing on dinosaur reproduction and ontogeny with researchers using these data to address a range of macroevolutionary questions about dinosaurs. Ontogeny, which is closely tied to osteological morphological variation, impacts several key research areas, such as taxonomic diversity, population dynamics, palaeoecology, macroevolution, as well as the physiological and reproductive factors driving ecological success. While these broad studies have significantly advanced our understanding of dinosaur evolution, they have also revealed important challenges and areas needing further investigation. In this review, we aim to outline some of these challenges in major research areas linked to dinosaur ontogeny, namely reproductive biology, osteohistological growth strategies, morphological osteological variation and the link between ontogeny and macroevolution. We also offer some recommendations for best practices and promising future research directions. These recommendations include increasing sample sizes through fieldwork and exhaustive use of pre-existing fossil collections, using micro-computed tomography (μCT) scanning methods to increase dataset sizes in a non-destructive manner, methodical collection and reposition of μCT scan data, assessing ontogenetic maturity, establishing consistency in terminology and methods and building comprehensive extant comparative datasets.", url = "https://doi.org/10.1098/rsbl.2024.0474", doi = "10.1098/rsbl.2024.0474", openalex = "W4406352887", references = "barta2022osteohistology, doi101002ar24130, doi101002ar24282, doi101016jgsf2024101872, doi101017s0094837300021308, doi10103824370, doi101038nature02699, doi101046j14610248200300505x, doi101073pnas0708903105, doi101098rsbl20230245, doi101111j14610248200500816x, doi101126science2665186779, doi101126scienceadc8714, doi101371journalpone0298242, doi1016710272463420000200115lbhoth20co2, doi1023072412825, doi104202app006982019, openalexw3215057009" } @article{porter2025honor, author = "Porter, Elliot", title = "Honor, Success, \& Futile Resistance: Here be Dragons", year = "2025", journal = "Philosophy \& Public Affairs", url = "https://doi.org/10.1111/papa.12280", doi = "10.1111/papa.12280", number = "1", openalex = "W4406053640", pages = "66-96", volume = "53" } @article{doi101038s43247025030836, author = "Chen, Jianbo and Niu, Yi-ning and Ma, Rongyao and Zhou, Yan-ling and Liu, Wen-jie and Wang, Yaming and You, Hai-Lu and Xu, Xing and Shen, Shu-Zhong and Feng, Zhuo", title = "Triassic–Jurassic environmental instability on the subtropical eastern Tethyan margin linked to low-latitude dinosaur dispersal", year = "2026", journal = "Communications Earth \& Environment", abstract = "The Triassic–Jurassic transition marks a critical interval, witnessing major biotic turnovers, including the rise of dinosaurs and the end-Triassic mass extinction, triggered by the Central Atlantic Magmatic Province. However, the volcanism linked to terrestrial ecosystem disturbance and dinosaur distribution remains poorly constrained. Here we present an integrated dataset of chemostratigraphic and astrochronological records for a continental drill core from the Kunming Basin in Yunnan Province of Southwest China, where rich dinosaur assemblages have been previously identified. Three negative carbon isotope excursions coupled with volcanogenic mercury anomalies confirm pulsed volcanism-induced environmental impacts on this subtropical terrestrial setting and placement of the Triassic–Jurassic boundary. Critically, the earliest regional sauropodomorph fossils occurred at \textasciitilde 200.17 Ma, indicating post-extinction colonization in low palaeolatitudes by medium- to large-bodied dinosaurs. Large-scale volcanism-induced stressors, potentially coupled with increased climate seasonality, likely created ecological opportunities facilitating dinosaur expansion in the earliest Jurassic. Early regional sauropodomorph fossils from 200.17 Ma suggest post-Triassic mass extinction dinosaur colonization in low paleolatitudes, likely due to Central Atlantic Magmatic Province stressors and increased climate seasonality, according to chemostratigraphic and astrochronological analysis of a core from the Kunming Basin in China.", url = "https://doi.org/10.1038/s43247-025-03083-6", doi = "10.1038/s43247-025-03083-6", openalex = "W7123351308", references = "chiarenza2024early, doi101016jcageo201902011, doi101016jcub202412053, doi101016jearscirev2019102880, doi101038299715a0, doi101086648222, doi101098rsbl20240429, doi101126science1161833, doi101126science1234204, doi101126science28554321386, doi1011300091761320020300251tameat20co2, doi101146annurevearth050212124107, doi101146annurevearth081320064052" }