''Tombaatar'' is a mammal

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

that existed during the

Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...

n Upper

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

. It co-existed with some of the late

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s. This animal was a member of the extinct order

Multituberculata Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, a ...

, within the suborder

Cimolodonta Cimolodonta is a taxon of extinct mammals that lived from the Cretaceous to the Eocene. They were some of the more derived members of the extinct order Multituberculata. They probably lived something of a rodent-like existence until their ...

and family

Djadochtatheriidae Djadochtatheriidae is a family of fossil mammals within the extinct order Multituberculata. Remains are known from the Upper Cretaceous of Central Asia. These animals lived during the Mesozoic, also known as the "age of the dinosaurs". This famil ...

. The genus ''Tombaatar'' was named by Rougier G.W., Novacek M. and Dashzeveg D. in 1997. The species ''Tombaatar sabuli'' is known from remains found in the

Upper Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', th ...

Djadokhta Formation The Djadochta Formation (sometimes transcribed and also known as Djadokhta, Djadokata, or Dzhadokhtskaya) is a highly fossiliferous geological formation situated in Central Asia, Gobi Desert, dating from the Late Cretaceous period, about 75 mill ...

of Ukhaa Tolgod,

. ''Tombaatar'' was a relatively large multituberculate. The

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

is about 6 cm in length.

References

* Rougier, Novacek & Dashzeveg (1997), "A new multituberculate from the late Cretaceous locality Ukhaa Tolgod, Mongolia: Considerations on multituberculate interrelationships", ''American Museum Novitates'' 3191, p. 1-26. * Kielan-Jaworowska, Z. & Hurum, J.H. (2001), "Phylogeny and Systematics of multituberculate mammals", ''Paleontology'' 44, p. 389-429. * Much of this information has been derived fro

Mesozoic Mammals: Djadochtatherioidea, an Internet directory. {{Taxonbar, from=Q3992628 Cimolodonts Cretaceous mammals Extinct mammals of Asia Prehistoric mammal genera