Mandschurosaurus

The Mandschurosaurus (meaning "lizard from Manchuria") are an extinct genus of hadrosaurids 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.

Mandschurosaurus
Temporal range: Late Cretaceous, ~
Holotype specimen of M. amurensis
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: †Ornithischia
Clade: †Ornithopoda
Family: †Hadrosauridae
Genus: †Mandschurosaurus
Riabinin, 1930
Type species
†Mandschurosaurus amurensis
Riabinin, 1925
Species
  • †M. amurensis (Riabinin, 1925)
  • †M. laosensis? Hoffet, 1944
Synonyms

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.[1] The holotype material was initially referred to the genus "Trachodon" (a nomen dubium) as T. amurense by Riabinin (1925),[2] but was later reassigned to a new genus by Riabinin (1930).[1]

The holotype of M. laosensis, which is based mainly on an ilium and other fragmentary remains,[3] comes from the Aptian-Albian-aged Grès supérieurs Formation in Laos and was named by Hoffet (1944).[4]

Description

While the holotype of M. amurensis would have measured 8 metres (26 ft) long and 4.5 metres (15 ft) tall, the largest specimen would have measured 11.24 metres (36.9 ft) long and 6.48 metres (21.3 ft) tall and weighed around 1.5-2 metric tons (3,300-4,400 pounds).[5]

It had a broad and flat beak and a long tail, similar to other related hadrosaurs.

Classification

There has been some debate regarding the validity of this genus. Brett-Surman (1979) first considered it a nomen dubium,[6] though some later workers have continued to see it as a valid taxon (Chapman et Brett Surman, 1990,[7] for example). Most recently, Horner et al. (2004) listed the type species as a nomen dubium in the second edition of The Dinosauria.[8]

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[6] and Horner et al. (2004) considered M. laosensis a nomen dubium;[8] 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.[8][6][7]

  • Reconstructed M. amurensis skeleton in outdated tripod-pose, VSEGEI Museum, St. Petersburg
    Reconstructed M. amurensis skeleton in outdated tripod-pose, VSEGEI Museum, St. Petersburg

See also

References
  1. Riabinin A. N. (1930). "Mandschurosaurus amurensis nov. gen, nov. sp. a hadrosaurian dinosaur from the Upper Cretaceous of the Amur River". Soc. Paleontol. Russ. Mem. 2: 1–36. [Russian]
  2. Riabinin, A.N. (1925). A mounted skeleton of the gigantic reptile Trachodon amurense, nov. sp. Izvest. Geol. Kom. 44(1):1-12. [Russian]
  3. Ruiz-Omeñaca, J.I. (2006). Restos directos de dinosaurios (Saurischia, Ornithischia) en el Barremiense (Cretácico Inferior) de la Cordillera Ibérica en Aragón (Teruel, España).
  4. 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
  5. Dashan Yang and Zhengyi Wei (1986). "Preliminary note on some hadrosaurs from the Cretaceous of Jiayin County, Heilongjiang Province (Manchuria)" (PDF). Nature Research of Heilongjiang Province. Heilongjiang Provincial Museum: 1–10.
  6. Brett-Surman M. K. (1979). "Phylogeny and palaeobiogeography of hadrosaurian dinosaurs". Nature. 277 (5697): 560–562. Bibcode:1979Natur.277..560B. doi:10.1038/277560a0. S2CID 4332144.
  7. 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.
  8. 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.


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