Summary
Pachysuchus is a dubious extinct genus of basal sauropodomorph dinosaur from the Early Jurassic of China.
| Pachysuchus Temporal range: Early Jurassic,
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|---|---|
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | †Sauropodomorpha |
| Genus: | †Pachysuchus Young, 1951 |
| Type species | |
| †Pachysuchus imperfectus Young, 1951
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Pachysuchus is known from a poorly preserved partial rostrum that was described from the Lower Lufeng Series in Yunnan by paleontologist Yang Zhongjian ("C.C. Young") in 1951.[1] The type species is Pachysuchus imperfectus. The generic name translates as "thick crocodile"; the specific name means "imperfect" in Latin. Young identified the rostrum as that of a phytosaur, a long-snouted crocodile-like crurotarsan. Phytosaurs were common in the Triassic, but none are otherwise known from the Jurassic. They are thought to have gone extinct during the Triassic-Jurassic extinction event. The rostrum from which Young described the specimen had since been lost, and his first description of the genus had been questioned.[2] The poor preservation of the specimen and its presence in Jurassic beds makes it doubtful that Pachysuchus is a phytosaur.[3] Paul M. Barrett and Xu Xing (2012) relocated the holotype of P. imperfectus, specimen IVPP V 40, and identified it as actually belonging to a taxonomically indeterminate basal sauropodomorph. According to Barrett and Xu, the holotype of Pachysuchus "does not bear any unique features or a unique character combination"; it differs from rostra of other Early Jurassic Chinese sauropodomorphs, but it cannot be ruled out that the differences are caused by its poor preservation, making it a nomen dubium.[4]
References edit
- ^ Young, C.C., 1951, "The Lufeng saurischian fauna in China", Palaeontologia Sinica, New Series C, 13: 1-96
- ^ Padian, K. (1989). "Did "thecodontians" survive the Triassic?". In Lucas, S.G.; Hunt, A.P. (eds.). Dawn of the Age of Dinosaurs in the American Southwest. Albuquerque: New Mexico Museum of Natural History. pp. 401–414.
- ^ Sun, A.-L.; Cui, K.H. (1986). "A brief introduction to the Lower Lufeng saurischian fauna (Lower Jurassic, Lufeng, Yunnan, People's Republic of China)". In Padian, K. (ed.). The Beginning of the Age of Dinosaurs: Faunal Change Across the Triassic-Jurassic Boundary. New York: Cambridge University Press. pp. 275–278.
- ^ Paul M. Barrett and Xu Xing (2012). "The enigmatic reptile Pachysuchus imperfectus Young, 1951 from the Lower Lufeng Formation (Lower Jurassic) of Yunnan, China" (PDF). Vertebrata PalAsiatica. 50 (2): 151–159.
