An enigmatic multituberculate mammal from the Early Cretaceous of Siberia, Russia

Baidabatyr clivosus, gen. et sp. nov. (Multituberculata incertae sedis), is described on the basis of an ultimate upper premolar (P5) from the Lower Cretaceous Ilek Formation at Bol'shoi Kemchug 3 locality in Krasnoyarsk Territory, Russia. The new taxon differs from all known multituberculates by the cusp formula of the ultimate upper premolar (4:5:5), cusps well separated by valleys of flat crown surface, and three roots. It shares with a few...