Zhelestidae

Zhelestidae is a lineage of extinct eutherian mammals. Occurring in the Late Cretaceous from the Turonian to the Maastrichtian, they were an extremely successful group, with representatives present in Europe, Asia, India (and subsequently in Madagascar), Africa and North America, ostensibly rendering them a cosmopolitan clade. They were specialised towards an herbivorous lifestyle and were in fact initially considered stem-ungulates, but the presence of epipubics and "archaic" dental characters render them as non-placental eutherians.

Ravjaa ishiii is an extinct species of zhelestid mammal from the Late Cretaceous of Mongolia. It is the type and only known species of the genus Ravjaa, which was described in 2025 based on a partial mandible recovered from the Bayanshiree Formation in the Gobi Desert.