The first record of Pliotragus (Artiodactyla: Bovidae) in the Early Pleistocene of eastern Asia; contribution to its systematics, palaeohabitat and palaeobiogeography

Pliotragus is a large-sized caprin within Bovidae, primarily known from the Late Pliocene to the Middle Pleistocene of Europe. To date, only a single site with this genus has been discovered in western Asia (Sarikol Tepe, Ankara, Turkey). It remains poorly understood due to insufficient material and study. In this paper, we report the first record of Pliotragus in eastern Asia (Xinyaozi locality, China) and compare it with some related taxa. The new specimens are similar to P. ardeus in cranial morphology and tooth measurements. However, considering certain differences between the horncore from Xinyaozi and that of its European counterparts, we classified the new material as Pliotragus cf. ardeus. Based on previously discovered material and our new specimens, we performed a Bayesian total-evidence dating analysis to determine the taxonomic status of the species. The results show that it should be placed in Caprini, clustering with the clade of Capricornis-Ovibos-Euceratherium, indicating closer relationships with Ovibos rather than Rupicapra, as previously proposed. We discuss whether P. ardeus might be a synonym of Sinoryx bombifrons based on similarities in their morphology and size. Additionally, we reconstructed its diet and habitat using dental and limb bone morphometric features. Pliotragus ardeus was likely a browse-dominated or mixed feeder that might have been adapted to both mountainous and plain regions, with intermediate diet and habitat preferences. Finally, we summarized its biostratigraphic position and palaeobiogeography, inferring that it dispersed from eastern Asia to Europe during the late Late Pliocene to early Early Pleistocene, probably triggered by increased glaciation.