Tatisaurus

{{Short description|Extinct genus of dinosaurs}} {{speciesbox | name = ''Tatisaurus'' | fossil_range = Early Jurassic, {{fossil_range|Sinemurian|earliest=Hettangian}} | image = Tatisaurus oehleri.jpg | image_caption = Jaw | display_parents = 2 | genus = Tatisaurus | parent_authority = Simmons, 1965 | species = oehleri | authority = Simmons, 1965 | synonyms = *''Bienosaurus lufengensis''? <small>Dong, 2001</small> *''Scelidosaurus oehleri'' <small>(Simmons, 1965) Lucas, 1996</small> }}

'''''Tatisaurus''''' is a genus of ornithischian dinosaur from the Early Jurassic from the Lower Lufeng Formation in Yunnan Province in China. Little is known as the remains are fragmentary.<ref>{{cite book|author=Dong Zhiming|year=1992|title=Dinosaurian Faunas of China|publisher=China Ocean Press, Beijing|isbn=978-3-540-52084-9|author-link=Dong Zhiming}}</ref> The type species is '''''T. oehleri'''''.

==Discovery and species==

In 1948 and 1949 Father Edgar Oehler, a Catholic priest working for the Fu Jen Catholic University at Beijing, excavated fossils near the village of Da Di in Yunnan. Among them was the jaw bone of a herbivorous dinosaur. In 1965 David Jay Simmons named and described it as the type species ''Tatisaurus oehleri''. The generic name is derived from Da Di, then more usually spelled as "Ta Ti". The specific name honours Oehler.<ref>Simmons D.J. (1965), The non-therapsid reptiles of the Lufeng Basin, Yunnan, China. ''Field Geol'' 15; 1-93.</ref> The holotype, '''FMNH CUP 2088''', was found in the Zhangjiawa Beds of the Lufeng Formation, dating from the Sinemurian. It consists of a partial left mandible with teeth. The lower jaw bone fragment is, lacking the tip, six centimetres long. The teeth are eroded. It is the only specimen known of the species.

Simmons assigned ''Tatisaurus'' to the Hypsilophodontidae, though this group was seen by him as an evolutionary grade of "primitive" Ornithopoda, ancestral to several ornithischian groups. He felt that ''Tatisaurus''' affinities were with ''Scelidosaurus'' or the Ankylosauria. Later, in 1990, the specimen was reviewed by Dong Zhiming, who noted it had similarities with ''Huayangosaurus''. He placed the two genera in the same subfamily, the Huayangosaurinae, within the Stegosauria.<ref>Z. Dong. (1990). "Stegosaurs of Asia". In: K. Carpenter and P. J. Currie (eds.), ''Dinosaur Systematics: Perspectives and Approaches'', Cambridge University Press, Cambridge pp. 255-268</ref>

Later still, in 1996, Spencer Lucas reclassified ''Tatisaurus oehleri'' as a species of ''Scelidosaurus'', ''S. oehleri'', in order to use ''Scelidosaurus'' for a biochron.<ref>Lucas S.G. (1996). The thyreophoran dinosaur ''Scelidosaurus'' from the Lower Jurassic Lufeng Formation, Yunnan, China. pp. 81-85, in Morales, M. (ed.), The Continental Jurassic. ''Museum of Northern Arizona Bulletin'' 60.</ref> In 2007, David B. Norman and colleagues regarded this as unfounded. They instead found ''Tatisaurus'' to be a dubious basal thyreophoran, showing a single thyreophorean synapomorphy; a ventrally deflected mesial end of the dentary. If considered a thyreophoran, it would be one of the oldest known members of the group.<ref name=NBM07>{{cite journal |last=Norman |first=David B. |author2=Butler, Richard J. |author3= Maidment, Susannah C.R. |year=2007 |title=Reconsidering the status and affinities of the ornithischian dinosaur ''Tatisaurus oehleri'' Simmons, 1965 |journal=Zoological Journal of the Linnean Society |volume=150 |pages=865–874 |doi=10.1111/j.1096-3642.2007.00301.x |issue=4 |doi-access=free }}</ref>

In 2019 a study concluded that ''Bienosaurus'' was a ''nomen dubium'', possibly identical to ''Tatisaurus'' from the same formation.<ref>Raven, T.J., Barrett, P.M., Xu, X., and Maidment, S.C.R. (2019). "A reassessment of the purported ankylosaurian dinosaur ''Bienosaurus lufengensis'' from the Lower Lufeng Formation of Yunnan, China". ''Acta Palaeontologica Polonica'' '''64'''</ref>

==References== {{Reflist}}

Category:Thyreophora Category:Dinosaur genera Category:Sinemurian dinosaurs Category:Lufeng Formation Category:Fossil taxa described in 1965 Category:Dinosaurs of China