Catopsbaatar is an extinct genus of mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

 that lived in Mongolia

Mongolia

Mongolia is a landlocked country in East and Central Asia. It is bordered by Russia to the north and China to the south, east and west. Although Mongolia does not share a border with Kazakhstan, its western-most point is only from Kazakhstan's eastern tip. Ulan Bator, the capital and largest...

 during 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...

 Period. It coexisted with some of the late 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...

s. This animal was a member of the extinct order Multituberculata

Multituberculata

The Multituberculata were a group of rodent-like mammals that existed for approximately one hundred and twenty million years—the longest fossil history of any mammal lineage—but were eventually outcompeted by rodents, becoming extinct during the early Oligocene. At least 200 species are...

 within the Suborder Cimolodonta

Cimolodonta

The Cimolodonta are 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 ecological niche was assumed by true rodents...

 and family Djadochtatheriidae

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 family is part of the suborder of Cimolodonta. The taxon...

.

The genus Catopsbaatar was named by Zofia Kielan-Jaworowska

Zofia Kielan-Jaworowska

Zofia Kielan-Jaworowska is a Polish paleobiologist. In the mid-1960s Kielan-Jaworowska led a series of Polish-Mongolian paleontological expeditions to the Gobi Desert...

 in 1974 and 1994 based on a single species. "One of the most characteristic features of Catopsbaatar (which differentiates it not only from Kryptobaatar

Kryptobaatar

Kryptobaatar and also known as Gobiaatar, Gobibaatar or Tugrigbaatar is an extinct mammalian genus dating from the Upper Cretaceous Period and identified in Central Asia...

but from all the djadochtatherioids in which the zygomatic ridges

Zygomatic arch

The zygomatic arch or cheek bone is formed by the zygomatic process of temporal bone and the temporal process of the zygomatic bone , the two being united by an oblique suture; the tendon of the Temporalis passes medial to the arch to gain insertion into the coronoid process...

 are known), is a very deep anterior zygomatic ridge, and a small medial zygomatic ridge, the latter forming about a quarter of a circle and adhering the anterior one from behind," (Kielan-Jaworowska et al., 2002).

The species Catopsbaatar catopsaloides has also been known as Catopsalis catopsaloides and Djadochtatherium catopsaloides (Kielan-Jaworowska 1974). Fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 remains were found in the Campanian

Campanian

The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...

 (Upper Cretaceous)-age strata

Stratum

In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...

 of Hermiin Tsav (Khermeen Tsav) in Mongolia. This was originally regarded as a species of Djadochtatherium

Djadochtatherium

Djadochtatherium is a mammal genus that lived in Mongolia during the Upper Cretaceous. It coexisted with some of the late dinosaurs. This animal was a member of the extinct order of Multituberculata. It's within the suborder of Cimolodonta, and a member of the family Djadochtatheriidae. It was...

. It also spent a while assigned to the North American genus Catopsalis

Catopsalis

Catopsalis is a genus of extinct mammal from the Paleocene of North America, though some Canadian finds may be upper Cretaceous. This animal was a relatively large member of the extinct order of Multituberculata. Most Multituberculates were much smaller....

(Cope 1882), courtesy of an interpretation in 1979 by Kielan-Jaworowska and Sloan. The original material consisted of three skull

Skull

The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...

s, the most complete of which was juvenile. Subsequently, a fourth specimen was identified and then an even more complete example came to light in 1999, along with some postcranial skeleton. This belonged to an elderly animal. It has been provisionally considered by Kielan-Jaworowska but has yet to be fully described. With a skull length of around 6 cm, this was a pretty large multituberculate.