A new dichobunoid artiodactyl from the middle Eocene of Yunnan, China

Abstract

Dichobunoids were the most basal artiodactyl group, widely distributed throughout the Eocene of Eurasia and North America, but were rarely reported from southern China. In this paper, we report the first dichobunoid artiodactyl, n. gen. n. sp., from the middle Eocene of Lunan Basin (Shilin County), China. is characterized by its relatively large size, bunoselenodont tooth morphology with a highly developed p4 metaconid, and a mesially interrupted paracristid formed by a weak premetacristid and a strong preprotocristid. This morphology distinguishes from all known dichobunoid artiodactyls. Within dichobunoids, resembles from the Eocene of Southeast Asia and “” from the Eocene of Shanxi, China, by the relatively large size, the absence of the paraconid, and the well-development of the hypolophid. However, still differs from and “” in the complete interruption of the paracristid and in the alignment of the entoconid and hypoconid as well as the protoconid and metaconiod. , , and “” might have derived from the Eocene from northern China, constituting a distinct group. The discovery of enhances our understanding of the early evolution of dichobunoid artiodactyls, especially in southern China.