AbstractTwo new species of ctenodactylid rodents, Prodistylomys taatsinius sp. nov. and Prodistylomys mongoliensis sp. nov., are described from the Valley of Lakes, Central Mongolia. They represent the first record of this genus in Mongolia. Prodistylomys is characterized by a simple dental pattern and high hypsodonty, reflecting an adaptation for tough vegetation in a dry environment, which is congruent with the aridification event that took place during the Late Oligocene and Early Miocene. We performed the most complete phylogenetic analysis combining the largest sampling in the family Ctenodactylidae and the best-represented stratigraphical distribution for the sample. This allowed us to propose that the origin of ctenodactylids lies in East Asia during the Eocene, and after that, the group dispersed through western Asia, Europe, and Africa. The presence of several similar rodent taxa in Mongolia, Kazakhstan, and China confirms that these areas were part of a large bioprovince covering most of central Asia during the Oligocene and Early Miocene.