Abstract

A new genus and species of dichobunid artiodactyl, Elaschitotherium qii, is described from the middle Eocene Shanghuang fissure-fillings of southern Jiangsu Province, China. This small form shares a number of dental features with North American homacodonts and the earliest hyperdichobunines (MP 13) from Europe, but it can be distinguished from both of these groups by several dental autapomorphies. E. qii shows greatest affinities with other Asian “dichobunoids” (Lantianius, and Eolantianius), and these three genera are tentatively united within a new subfamily of Asian dichobunids, the Lantianiinae. Lantianiines may be related to D. pakistanensis, but they do not seem to be closely related to other dichobunids from the early–middle Eocene of the Indo-Pakistani region. The occurrence of E. qii in Shanghuang suggests that bunoselenodont artiodactyls radiated synchronously in Asia, Europe, and North America. Further material is required to understand more fully the phylogenetic relationships among lantianiines and other subfamilies of European and North American dichobunids. However, it appears that the selenodont grade of dental adaptation was independently acquired in several lineages of dichobunids inhabiting the three northern landmasses during the middle Eocene. For the first time in Asia, early ruminants and dichobunids have been recovered in direct association at a single site—Shanghuang fissure D (Irdinmanhan ALMA). Further investigation of the Shanghuang artiodactyl fauna promises to improve our knowledge of the evolution of dichobunids in Asia. This, in turn, will shed new light on the origin of the Ruminantia and other extinct selenodont groups.