New material of Miotragocerus (Bovidae, Artiodactyla) from northern China and its systematic implications

Late Miocene tragoportacins are widespread in Eurasia and Africa and are important members of the Hipparion fauna. The phylogenetic relationships within the tragoportacins are debatable due to the large number of species, fragmentary materials, and large intraspecific variations. The Chinese tragoportacins are rare and poorly studied in previous work. Recently, a dozen well-preserved skulls were excavated from northern China, providing important information for the classification and phylogenetic analysis of the Chinese tragoportacins. In this study, we assign the new material from Linxia Basin and Fugu County to Miotragocerus gregarius, providing detailed descriptions of both males and females. We discuss sexual dimorphism and compare the horn core, dentition and cranium characters in Miotragocerus, Tragoportax and related species. We also perform cladistic analyses, including Eurasian and African tragoportacins, Tetracerus and Eotragus. The phylogenetic analysis indicates that the two Chinese late Miocene tragoportacins belong to Miotragocerus and Tragoportax, which immigrated from the west to China in different periods.