Mongolosaurus

Mongolosaurus
Temporal occurrence
	Lower Cretaceous
	145 to 100.5 million years
Locations
	Inner Mongolia , China ( On Gong formation );
Systematics
	Dinosaur (dinosauria)
	Lizard dinosaur (Saurischia)
	Sauropodomorpha
	Sauropoda
	Titanosaurs (Titanosauria)
	Mongolosaurus
Scientific name
	Mongolosaurus
	Gilmore , 1933
Art
	Mongolosaurus haplodon;

Mongolosaurus is a genus of little-known sauropod dinosaurs from the Titanosauria group from the Lower Cretaceous China. It was described in 1933 by the paleontologist Charles Gilmore using very fragmentary remains that were found in Inner Mongolia ( On-Gong formation )in 1928. The only species is Mongolosaurus haplodon . Some authors consider Mongolosaurus to be a noun dubium (dubious name).

Find and features

The find ( holotype , copy number AMNH 6710) is in the collection of the American Museum of Natural History and consists of a partial brain skull ( basioccipital ), incompletely preserved teeth and the first three cervical vertebrae.

An examination of the findings by Wilson (2005) comes to the conclusion that Mongolosaurus can be distinguished from other genera by at least three unique features ( autapomorphies ) on the anterior cervical vertebrae: On the one hand, the spinous processes of the vertebrae were greatly reduced. The epipophyses were well developed. Furthermore, the spinoprezygapophyseal and the spinopostzygapophyseal lamina (flat sections of the vertebral arches ) were oriented almost horizontally.

Systematics

The systematic classification was controversial for a long time. Various authors classified it as a sauropod that cannot be classified further (Sauropoda incertae sedis ), such as Gilmore (1933) or McIntosh (1990). Barrett and colleagues (2002) and Wilson (2002) classified the genus as Neosauropoda incertae sedis. Young (1958) and von Huene (1959) saw Mongolosaurus as a representative of the Diplodocidae . Still other studies did not give a systematic classification, but instead used the genus as the noun dubium , thus casting doubt on the validity of the genus. More recent studies by Wilson (2005) and Barrett and Wang (2007) classify Mongolosaurus as Nemegtosaurids within the Titanosauria. The Mongolosaurus cranium shows a common feature ( synapomorphism ) of the Nemegtosauridae - the laterally and ventrally widened basal tubera (an extension below the occipital condyle).

History of discovery, find and naming

The remains were discovered on June 3, 1928 by Dr. Walter Granger discovered during an expedition to the American Museum of Natural History in Hu-Khung-Ulan. This and other material from other expeditions was given to Charles Gilmore for investigation, who published a description of the finds in 1933. Gilmore saw the naming of a new genus and species justified in spite of the very few fossils, since the teeth differ significantly from all sauropod teeth known until then. The teeth show a largest diameter of up to nine millimeters and were quite slender - Gilmore wrote that they are most likely to be compared with teeth of Diplodocus and Pleurocoelus . In the same publication, Gilmore described the ankylosaur Pinacosaurus .

Mongolosaurus ("Mongolian lizard") is named after Inner Mongolia, where the fossils were discovered.

In 2003, Averianov and colleagues described a tooth fragment from the Murtoi formation in eastern Russia (Mogoito site, specimen number ZIN PH 4/13) also as Mongolosaurus , as cf. Mongolosaurus sp.

Individual evidence

↑ ^a ^b ^c Charles W. Gilmore : Two new dinosaurian reptiles from Mongolia with notes on some fragmentary specimens (= American Museum Novitates. No. 679, ISSN 0003-0082 ). American Museum of Natural History, New York NY 1933, online .
^ ^A ^b Paul Upchurch , Paul M. Barrett , Peter Dodson : Sauropoda. In: David B. Weishampel , Peter Dodson, Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. a. 2004, ISBN 0-520-24209-2 , pp. 259-324.
↑ ^a ^b Jeffrey A. Wilson: Redescription of the Mongolian Sauropod Nemegtosaurus mongoliensis Nowinski (Dinosauria: Saurischia) and comments on Late Cretaceous Sauropod diversity. In: Journal of Systematic Palaeontology. Vol. 3, No. 3, 2005, ISSN 1477-2019 , pp. 283-318, doi: 10.1017 / S1477201905001628 .
↑ Mongolosaurus. In: The Paleobiology Database. Retrieved March 28, 2019 .
↑ Ben Creisler: Dinosauria Translation and Pronunciation Guide ( Memento November 11, 2011 in the Internet Archive )
↑ Alexander O. Averianov, Pavel P. Skutschas: Additions to the Early Cretaceous Dinosaur Fauna of Transbaikalia, Eastern Russia. In: Proceedings of the Zoological Institute of the Russian Academy of Sciences. Vol. 313, No. 4, 2009, ISSN 0206-0477 , pp. 363-378, digital version (PDF; 846 kB) .

[gilmore_1933-1] Charles W. Gilmore : Two new dinosaurian reptiles from Mongolia with notes on some fragmentary specimens (= American Museum Novitates. No. 679, ISSN 0003-0082 ). American Museum of Natural History, New York NY 1933, online .

[dinosauria-2] A ^b Paul Upchurch , Paul M. Barrett , Peter Dodson : Sauropoda. In: David B. Weishampel , Peter Dodson, Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. a. 2004, ISBN 0-520-24209-2 , pp. 259-324.

[nemegtosaurus-3] Jeffrey A. Wilson: Redescription of the Mongolian Sauropod Nemegtosaurus mongoliensis Nowinski (Dinosauria: Saurischia) and comments on Late Cretaceous Sauropod diversity. In: Journal of Systematic Palaeontology. Vol. 3, No. 3, 2005, ISSN 1477-2019 , pp. 283-318, doi: 10.1017 / S1477201905001628 .

[paleobd-4] Mongolosaurus. In: The Paleobiology Database. Retrieved March 28, 2019 .

[5] Ben Creisler: Dinosauria Translation and Pronunciation Guide ( Memento November 11, 2011 in the Internet Archive )

[averianov-6] Alexander O. Averianov, Pavel P. Skutschas: Additions to the Early Cretaceous Dinosaur Fauna of Transbaikalia, Eastern Russia. In: Proceedings of the Zoological Institute of the Russian Academy of Sciences. Vol. 313, No. 4, 2009, ISSN 0206-0477 , pp. 363-378, digital version (PDF; 846 kB) .