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
Kielan-Jaworowska and American palaeontologist Robert E. Sloan considered the genus "Djadochtatherium" a junior synonym of "Catopsalis", and created the new combination "C. catopsaloides" in 1979. American palaeontologists Nancy B. Simmons and Miao Desui conducted a 1986 cladistic analysis which indicated that "Catopsalis" was a paraphyletic taxon (an unnatural grouping of species), and "C. catopsaloides" required its own generic name. Kielan-Jaworowska followed Simmons and Miao's suggestion, moving "C. catopsaloides" to its own monotypic genus ("Catopsbaatar") in 1994. "Catops" is derived from the Greek word "katoptos" ("visible" or "evident"); "baatar" is Mongolian for "hero", and the name refers to "Catopsbaatar"'s similarity to the genus "Catopsalis" (as is the case for the specific name). The name "Catopsalis" itself consists of the Greek words for "visible" and "cutting shears" ("psalis").
Later in 1994, Kielan-Jaworowska and the Russian palaeontologist Petr P. Gambaryan mentioned caudal (tail) vertebrae which may have belonged to "Catopsbaatar"; this attribution is uncertain, since they may instead belong to the related "Tombaatar" (named in 1997). A fourth skull (PIN 4537/4, a juvenile), discovered during the 1975 Soviet−Mongolian Expedition, was mentioned by Gambaryan and Kielan-Jaworowska in 1995. Canadian palaontologist Phillip J. Currie found a new "Catopsbaatar" specimen during the 1999 Dinosaurs of the Gobi expedition, organised by the American Nomadic Expeditions Company. Housed at the Mongolian Academy of Sciences in Ulaanbaatar as PM120/107, this most completely preserved known specimen consists of the complete skull (which may be slightly flattened) and partial skeleton of an adult individual. The specimen has rather complete fore- and hind limbs, which were unknown for the genus until then and which are generally rarely preserved in multituberculates. Its pelvic ilia were stolen and destroyed by a schoolboy on tour at the Natural History Museum of Oslo, when it was prepared in 2000. The specimen was reported in 2002 by Kielan-Jaworowska, Norwegian palaeontologist Jørn Hurum, Currie and Mongolian palaeontologist Rinchen Barsbold, who also mentioned another skull (PIN 4537/5, a juvenile) found during the 1975 expedition. "Catopsalis joyneri", the basis of the name "C. catopsaloides", was moved to the new genus "Valenopsalis" in 2015.