A Complete Skeleton of a Late Triassic Saurischian and the Early Evolution of Dinosaurs

@article{Nesbitt2009ACS,
  title={A Complete Skeleton of a Late Triassic Saurischian and the Early Evolution of Dinosaurs},
  author={Sterling J. Nesbitt and Nathan D Smith and Randall B. Irmis and Alan H. Turner and Alex Downs and Mark A. Norell},
  journal={Science},
  year={2009},
  volume={326},
  pages={1530 - 1533}
}
Early Dinosaur Discovery Our understanding of the evolution of early dinosaurs is hampered by limited material, especially compared to the many Jurassic and Cretaceous samples. Nesbitt et al. (p. 1530) provide a complete view of a Late Triassic theropod based on several nearly complete skeletons from New Mexico. The dinosaur elucidates the likely relationships between early theropods and shows that some prominent features were already derived by this time. Comparison among Triassic dinosaur… 

A palaeoequatorial ornithischian and new constraints on early dinosaur diversification

TLDR
A new dinosaur from the earliest Jurassic of the Venezuelan Andes is the first basal ornithischian recovered from terrestrial deposits directly associated with a precise radioisotopic date and the first-named dinosaur from northern South America, helping to underscore the importance of the ornithische record in broad-scale discussions of early dinosaur history.

Basal dinosauriform and theropod dinosaurs from the mid–late Norian (Late Triassic) of Poland: implications for Triassic dinosaur evolution and distribution

The rise of dinosaurs during the Triassic is a widely studied evolutionary radiation, but there are still many unanswered questions about early dinosaur evolution and biogeography that are hampered

A late-surviving basal theropod dinosaur from the latest Triassic of North America

TLDR
Various features of the skull of Daemonosaurus, including the procumbent dentary and premaxillary teeth and greatly enlarged premaxilla and anterior maxillary teeth, clearly set this taxon apart from coeval neotheropods and demonstrate unexpected disparity in cranial shape among theropod dinosaurs just prior to the end of the Triassic.

A new early dinosaur (Saurischia: Sauropodomorpha) from the Late Triassic of Argentina: a reassessment of dinosaur origin and phylogeny

TLDR
The new evidence presented here demonstrates that dinosaurs first appeared in the fossil record as a diverse group, although they were a numerically minor component of faunas in which they occur.

A Triassic averostran-line theropod from Switzerland and the early evolution of dinosaurs

TLDR
An exceptionally well-preserved theropod skeleton from the Late Triassic of Europe pertaining to a new genus and species informs the evolution of coelophysids and dilophosaurids.

The origins of Dinosauria: much ado about nothing

  • M. Langer
  • Geography, Environmental Science
  • 2014
Research this century has greatly improved our knowledge of the origin and early radiation of dinosaurs. The unearthing of several new dinosaurs and close outgroups from Triassic rocks from various

Dispersal and diversity in the earliest North American sauropodomorph dinosaurs, with a description of a new taxon

  • T. RoweH. SuesR. Reisz
  • Environmental Science, Geography
    Proceedings of the Royal Society B: Biological Sciences
  • 2010
TLDR
The finding of separate arrivals by all three taxa suggests dispersal as a chief factor in dinosaurian diversification during at least the early Mesozoic, and questions whether a ‘cosmopolitan’ dinosaur fauna ever existed, and corroborates that vicariance, extinction and dispersal did not operate uniformly in time or under uniform conditions during the Mesozoics.

FRONTIERS IN PALAEONTOLOGY THE ORIGINS OF DINOSAURIA: MUCH ADO ABOUT NOTHING

  • M. Langer
  • Geography, Environmental Science
  • 2014
Research this century has greatly improved our knowledge of the origin and early radiation of dinosaurs. The unearthing of several new dinosaurs and close out- groups from Triassic rocks from various
...

References

SHOWING 1-10 OF 33 REFERENCES

A critical re‐evaluation of the Late Triassic dinosaur taxa of North America

Synopsis The North American Triassic dinosaur record has been repeatedly cited as one of the most complete early dinosaur assemblages. The discovery of Silesaurus from Poland and the recognition that

Early ornithischian dinosaurs: the Triassic record

Abstract Ornithischian dinosaurs are one of the most taxonomically diverse dinosaur clades during the Mesozoic, yet their origin and early diversification remain virtually unknown. In recent years,

Osteology of Cryolophosaurus ellioti (Dinosauria: Theropoda) from the Early Jurassic of Antarctica and implications for early theropod evolution

TLDR
An in-depth morphological description of Cryolophosaurus is pre-sented here, along with a rigorous phylogenetic analysis of theropod relationships consisting of 347 characters and 56 taxa, in an attempt to clarify the relationships of Crylophosaurus and to provide insight into questions sur-rounding early theropid evolution.

Hindlimb Osteology and Distribution of Basal Dinosauromorphs from the Late Triassic of North America

TLDR
An ontogenetic series of the femur of Dromomeron indicates that some character states previously used in phylogenetic analyses of early dinosaurs may be ontogenetically variable.

A Late Triassic Dinosauromorph Assemblage from New Mexico and the Rise of Dinosaurs

TLDR
The transition between the first dinosaurs and more archaic faunas may have extended for 15 to 20 million years and was probably diachronous at different paleolatitudes.

A review of the systematic position of the dinosauriform archosaur Eucoelophysis baldwini sullivan & lucas, 1999 from the upper triassic of New Mexico, USA

TLDR
A cladistic analysis was carried out, which depicts Eucoelophysis as a non-dinosaurian dinosauriform, indicating their survival into the Norian, being co-eval with early dinosaurs.

A Middle Jurassic ‘sphenosuchian’ from China and the origin of the crocodylian skull

TLDR
Important features of the modern crocodylian skull evolved during a phase when the postcranial skeleton was evolving towards greater cursoriality, rather than towards their current semi-aquatic habitus.

Basal Dinosauriform Remains from Britain and the Diagnosis of the Dinosauria

TLDR
The definition and diagnosis of the Dinosauria are restated and the positions of the new form, herrerasaurs and Eoraptor relative to true dinosaurs are discussed.

An analysis of dinosaurian biogeography: evidence for the existence of vicariance and dispersal patterns caused by geological events

TLDR
The results provide the first statistically robust evidence that, from Middle Jurassic to mid‐Cretaceous times, tectonic events had a major role in determining where and when particular dinosaur groups flourished.

The Complete Skull and Skeleton of an Early Dinosaur

TLDR
Fossils of Herrerasaurus and younger dinosaurs from Upper Triassic beds in Argentina suggest that the dinosaurian radiation was well under way before dinosaurs dominated terrestrial vertebrate communities in taxonomic diversity and abundance.