The First Capybaras (Rodentia, Caviidae, Hydrochoerinae) Involved in the Great American Biotic Interchange

Abstract

The new combination Phugatherium dichroplax nov. comb. (Ahearn and Lance) is proposed for the North American species “Neochoerus” dichroplax Ahearn and Lance, and “N.” cordobai Carranza-Castañeda and Miller. Its age range is here expanded (late Early Blancan—latest Blancan; Piacenzian—Gelasian), being the youngest species of Phugatherium and thus extending the biochron of the genus into the early Pleistocene. This is the first mention of a Pliocene South American lineage of capybaras crossing the Panamanian bridge, implying the recognition of a third lineage of capybaras involved in the Great American Biotic Interchange. The proposed North American origin of the genus Neochoerus is discussed.