Mandschurosaurus

''Mandschurosaurus'' (meaning "lizard from Manchuria") is an extinct genus of hadrosaurs based on material from the Late Cretaceous of China and possibly also the Early Cretaceous of Laos. It was the first dinosaur genus named from China, and a mounted skeleton based on the holotype of ''M. amurensis'' is on display at the Central Geological and Prospecting Museum in St. Petersburg; however, much of the skeleton is plaster.

Discovery and naming

The holotype of ''M. amurensis'' (IVP AS coll.), the only valid species within the genus, is based on a poorly preserved and incomplete skeleton collected by Russian scientists in 1914 from the banks of the Amur River, China in a layer of the Maastrichtian-aged Yuliangze Formation and the remains represent a large hadrosaurid. ussian/ref> The holotype material was initially referred to the genus ''"Trachodon"'' (a ''nomen dubium'') as ''T. amurense'' by Riabinin (1925),Riabinin, A.N. (1925). A mounted skeleton of the gigantic reptile ''Trachodon amurense'', nov. sp. ''Izvest. Geol. Kom.'' 44(1):1-12. ussian/ref> but was later reassigned to a new genus by Riabinin (1930). The holotype of ''M. laosensis'', which is based mainly on an ilium and other fragmentary remains, comes from the Aptian-Albian-aged Grès supérieurs Formation in Laos and was named by Hoffet (1944).J.-H. Hoffet. (1944). Description of the most characteristic bones belonging to Avipelvians from the Senonian of Lower Laos. ''Minutes of the Sessions of the Council for Scientific Research of Indochina'' 1944:179-186

Description

''M. amurensis'' would likely have reached up to when fully grown.

Classification

There has been some debate regarding the validity of this genus. Brett-Surman (1979) first considered it a ''nomen dubium'', though some later workers have continued to see it as a valid taxon (Chapman et Brett Surman, 1990,Chapman R. et Brett-Surman M. K. (1990). Morphometric observations on hadrosaurid ornithopods. in Carpenter K. et Currie, P. J. (eds.), ''Dinosaur Systematics: Perspectives and Approaches'', Cambridge University Press, Cambridge 163-177. for example). Most recently, Horner ''et al.'' (2004) listed the type species as a ''nomen dubium'' in the second edition of ''The Dinosauria''.Horner J., Weishampel D. B., et Forster C. A. (2004). Chapter Twenty: Hadrosauridae. in ''The Dinosauria'' (2nd edition), Weishampel D. B., Dodson P., and Osmólska H., editors. University of California Press.

Over the years, three species have been placed within this genus: ''Mandschurosaurus amurensis'', ''M. mongoliensis'', and ''M. laosensis''. Brett-Surman (1979) considered ''M. mongoliensis'' a distinct genus, which he named ''Gilmoreosaurus'' and Horner ''et al.'' (2004) considered ''M. laosensis'' a ''nomen dubium''; This leaves only Riabinin's original species, ''M. amurensis'', as a possibly valid taxon.

Within Ornithopoda, ''Mandschurosaurus'' is most often placed within Hadrosauridae as a ''nomen dubium''.

Gallery

Mandschurosaurus Amurensis..2H1A0401WI.jpg, Reconstructed ''M. amurensis'' skeleton in outdated tripod-pose, VSEGEI Museum, St. Petersburg

See also

* Timeline of hadrosaur research

References

{{Taxonbar, from=Q1076898

Late Cretaceous dinosaurs of Asia
Hadrosaurs
Fossil taxa described in 1930
Ornithischian genera