Yakutia sukachevae gen. et sp. nov. (Mordellidae), the first fossil Coleoptera from Upper Cretaceous amber of Yakutia, eastern Russia

Abstract

Cretaceous amber faunas of North Asia are well-known from Taymyr, but the Santonian floras of Taymyr are virtually unstudied. Conversely, the Cenomanian floras of Yakutia are well-studied, but the amber fauna of Yakutia remains unknown. Yakutia sukachevae gen. et sp. nov. is described from Cenomanian (∼95 Ma) retinite from Yakutia (Russia). The specimen is one of the oldest known mordellid fossil in amber, and the first recorded from Yakutian amber. The taxon appears “less mordellid-like” than all other known fossil Mordellidae, primarily due to the slightly dorsally compressed habitus, the less strongly developed, distinctly transverse coxal plate, and the slightly serrate, tetratomid-like antennae. Yakutia sukachevae is assigned to Mordellidae primarily based on the presence of the proepisternal suture separating the pronotal disc and proepisterna, the hemispherical head, the expanded coxal plate and the obliquely truncated hind tibiae.