Study on the new dental material of Palaeotragus from the late miocene of Linxia Basin (Gansu, China)

Palaeotragus is a common genus of the Giraffidae that was widely distributed in the Neogene strata of Eurasia. Early studies usually placed small giraffids in the Palaeotragus clade, leading to considerable controversy over the validity and systematic classification of this genus. Palaeotragus microdon and Palaeotragus cf. coelophrys are two representative species of Palaeotragus in China, their dental specimens are mainly distinguished by size, causing problems in their actual identification. In this study, several mandibles of a small giraffid found in Linxia Basin, Gansu Province, China (MN 10-13), are studied and identified as Palaeotragus cf. coelophrys. Based on a detailed comparison, the size and morphological variability of the Chinese Palaeotragus dental material are discussed, as well as the validity of the two species and the validity of other Eurasian Palaeotragus. This study reveals that the Chinese Palaeotragus has a continuous sequence of size variability and premolar features, which is insufficient to separate the mandible of the two species. In addition, the type species P. rouenii can be clearly distinguished from the Chinese Palaeotragus by the relatively long lower premolar row, possibly due to the difference in feeding habits. The holotype of P. coelophrys is closely related to Chinese Palaeotragus, while the P. coelophrys mandible from Maragheh (MMTT37 2517) should belong to different species.