"One of the most characteristic features of Catopsbaatar (which differentiates it not only from Kryptobaatar but from all the djadochtatherioids in which the zygomatic ridges 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).
Animals that may have shared the same habitat with Tsaagan include Protoceratops, Shuvuuia, the small mammal Zalambdalestes, the multituberculate mammal Kryptobaatar, as well as several lizards and two yet-undescribed species of troodontid and dromaeosaurid.