Mandschurosaurus
Encyclopedia
Mandschurosaurus is a hadrosaur taxon
based on material from the Upper Cretaceous
of Belye Kruchi, Manchuria
. M. amurensis is based on a poorly preserved and incomplete skeleton collected by Russia
n scientists in 1914 from the banks of the Amur River. It was the first dinosaur
genus
named from China
, and an impressive mounted skeleton is on display at the Central Geological and Prospecting Museum in St. Petersburg. However, much of the skeleton is plaster
. Regardless, the remains represent a very large hadrosaurid, at least 8 metres in length. 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, for example). Most recently, Horner et al. (2004) listed the type species as a nomen dubium. The holotype material was initially referred to the genus "Trachodon
" (also a nomen dubium), but later reassigned to a new genus by Riabinin (1930).
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
. Horner et al. (2004) considered M. laosensis a nomen dubium. This leaves only Raibinin's original species, M. amurensis, as a possibly valid taxon.
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
based on material from the Upper Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
of Belye Kruchi, Manchuria
Manchuria
Manchuria is a historical name given to a large geographic region in northeast Asia. Depending on the definition of its extent, Manchuria usually falls entirely within the People's Republic of China, or is sometimes divided between China and Russia. The region is commonly referred to as Northeast...
. M. amurensis is based on a poorly preserved and incomplete skeleton collected by Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
n scientists in 1914 from the banks of the Amur River. It was the first dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
named from China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, and an impressive mounted skeleton is on display at the Central Geological and Prospecting Museum in St. Petersburg. However, much of the skeleton is plaster
Plaster
Plaster is a building material used for coating walls and ceilings. Plaster starts as a dry powder similar to mortar or cement and like those materials it is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after setting,...
. Regardless, the remains represent a very large hadrosaurid, at least 8 metres in length. There has been some debate regarding the validity of this genus. Brett-Surman (1979) first considered it a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
, though some later workers have continued to see it as a valid taxon (Chapman et Brett Surman, 1990, for example). Most recently, Horner et al. (2004) listed the type species as a nomen dubium. The holotype material was initially referred to the genus "Trachodon
Trachodon
Trachodon is a dubious genus of hadrosaurid dinosaur based on teeth from the Campanian-age Upper Cretaceous Judith River Formation of Montana, U.S.A...
" (also a nomen dubium), but later reassigned to a new genus by Riabinin (1930).
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
Gilmoreosaurus
Gilmoreosaurus is the name given to a genus of dinosaur from the Cretaceous of Asia. The type species is Gilmoreosaurus mongoliensis. It is believed to be a hadrosaur or iguanodont from the Iren Dabasu Formation of Mongolia, dating to 70 Ma ago. Additional specimens have been described as distinct...
. Horner et al. (2004) considered M. laosensis a nomen dubium. This leaves only Raibinin's original species, M. amurensis, as a possibly valid taxon.