The genus Chulsanbaatar was named by Zofia Kielan-Jaworowska in 1974 , after the locality of Khulsan near the dig sites where these organisms were found, and Ulan Bator, the capital of Mongolia.
[1] Fossil remains of the species Chulsanbaatar vulgaris have been found in multiple localities in the Gobi Desert, including the Red Beds of Hermiin Tsav (also known as Khermeen Tsav, part of the Barun Goyot Formation) in Mongolia.
They range in the fossil record from 84 to 71 million years ago, from the late Santonian, through the Campanian and early Maastrichtian ages.
[3] The adult body mass has been estimated at 12 grams (0.42 oz),[4] which is similar to a small modern mouse.
[5] The type specimen of Chulsanbaatar is now a resident of the Polish Academy of Science in Warsaw, Poland.