Catopsbaatar
Catopsbaatar is a genus of multituberculate, an extinct order of rodent-like mammals. It lived in what is now Mongolia during the late Campanian age of the Late Cretaceous Period, about 72 million years ago. The first fossils were collected in the early 1970s, and the animal was named as a new species of the genus "Djadochtatherium " in 1974, "D. catopsaloides". The specific name refers to the animal's similarity to the genus "Catopsalis". The species was moved to the genus "Catopsalis" in 1979, and received its own genus ("Catopsbaatar", Greek and Mongolian for "visible hero") in 1994. Five skulls, one molar, and one skeleton with a skull are known; the latter is the genus' most complete specimen. "Catopsbaatar" was a member of the family Djadochtatheriidae.
Catopsbaatar
In 1970 and 1971, the Polish-Mongolian Palaeontological Expeditions collected mammalian fossils from the Red Beds of Hermiin Tsav formation in Mongolia's Gobi Desert. About 100 specimens, recovered from four localitions, are housed at the Polish Academy of Sciences in Warsaw. Two-thirds of the collected specimens were multituberculates: an extinct order of mammals with rodent-like dentition, named for the numerous cusps (or tubercles) on their molars. In 1974, Polish palaeontologist Zofia Kielan-Jaworowska named a new species of the Mongolian multituberculate genus "Djadochtatherium" as "D. catopsaloides", with specimen ZPAL MgM−I/78 from the Polish collection as the holotype. The specific name refers to the animal's similarity to the North American species "Catopsalis joyneri", which Kielan-Jaworowska thought was a possible descendant. The specimen, collected at the Hermiin Tsav I location, is an almost-complete skull of a juvenile with portions of the cranium damaged. Kielan-Jaworowska also assigned other specimens to the species: a damaged skull missing lower jaws (ZPAL MgM−I/79, an adult), a skull with partial lower jaws (ZPAL MgM−I/80), and a molar with a fragment of jaw (ZPAL MgM−I/159 from the Barun Goyot Formation of Khulsan, the only specimen not from Hermiin Tsav).