First Apatemyid Mammal from Central Asia.

Asiapator onchin gen. et sp. nov. is based on a dentary fragment from the middle Eocene (Irdinmanhan) Khaychin Formation at Khaychin Ula 3 locality, Mongolia. The preserved dentition includes di1 being replaced by i1, dp2 or p2, roots of dp4, and erupting p4. This is the first record of the Apatemyidae in Central Asia. The holotype of A. onchin provides the first direct evidence for dental replacement in the Apatemyidae, showing diphyodont first lower incisor and fourth lower premolar. Asiapator has only one lower incisor as in all apatemyids except Unuchinia from the Paleocene of North America. Asiapator is similar to Unuchinia and differs from more derived apatemyids in having a simple unmodified anterior premolar (dp2 or p2). Asiapator likely evolved from a North American immigrant. [ABSTRACT FROM AUTHOR]