Asiatherium

Asiatherium
Temporal range: Late Cretaceous (Campanian) 83.6 Ma
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Holotype of Asiatherium
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: †Asiadelphia
Family: †Asiatheriidae
Genus: †Asiatherium
Trofimov & Szalay, 1994
Species:
†A. reshetovi
Binomial name
†Asiatherium reshetovi
Trofimov & Szalay, 1994

Asiatherium is an extinct genus of mammal, probably belonging to Metatheria. It lived during the Late Cretaceous, and its fossilized remains were discovered in Mongolia.

Description

Skull of Asiatherium is 30 mm (1.2 in) in length.[1] This animal was roughly the size of a mouse, and is known from a fairly complete articulated skeleton, preserving a complete skull. Its teeth resembled roughly those of marsupials; it possessed three premolars and four molars, and the mandible was slightly curved. Compared to Deltatheridium, Asiatherium was even more marsupial-like, due to its molars having paraconids lower than the metaconids, and the paired entoconid-hypoconulid cusps on the lower molars. The stylar platform of the upper molars was however narrower and the stylar cusps weaker than in primitive marsupials. The upper molars differed from those of marsupials in their expanded praecingula and postcingula.[2]

Classification

Asiatherium reshetovi was first described in 1994, based on fossils found in the Udan-Sayr locality of the Djadokhta Formation, in Mongolia. Asiatherium seems to be related to early marsupials, but probably was nested within a different clade of Metatherian, Deltatheroida, nested alongside Deltatheridium. The skeleton of Asiatherium looked like that of a basal Therian; epipubic bones, typical of marsupials, were present.

References and Bibliography

  1. ^ Zofia Kielan-Jaworowska, Richard L. Cifelli, Zhe-Xi Luo (2004). Mammals from the Age of Dinosaurs: origins, evolution, and structure. New York: Columbia University Press. p. 428. ISBN 978-0-231-11918-4.{{cite book}}: CS1 maint: multiple names: authors list (link)
  2. ^ *F. S. Szalay and B. A. Trofimov. 1996. The Mongolian Late Cretaceous Asiatherium, and the early phylogeny and paleobiogeography of Metatheria. Journal of Vertebrate Paleontology 16(3):474-509
  • B. A. Trofimov and F. S. Szalay. 1994. New Cretaceous marsupial from Mongolia and the early radiation of Metatheria. Proceedings of the National Academy of Sciences 91:12569-12573
  • T. E. Williamson, S. L. Brusatte, T. D. Carr, A. Weil, and B. R. Standhardt. 2012. The phylogeny and evolution of Cretaceous–Palaeogene metatherians: cladistic analysis and description of new early Palaeocene specimens from the Nacimiento Formation, New Mexico. Journal of Systematic Palaeontology 10(4):625-651