New Olonbulukia material and its related assemblage reveal an early radiation of stem Caprini along the north of the Tibetan Plateau

Living Caprini are dominant bovids in the pan-Tibetan area that are strongly adapted to dry steppe and high mountain meadow habitats. Some taxa with Holarctic distributions, such as Ovis, were thought to originate on the Tibetan Plateau and subsequently dispersed elsewhere, which was depicted as an “out of Tibet” story. However, except for some information on a stem caprine assemblage from the Qaidam Basin, the early evolution of Caprini around the Tibetan Plateau is poorly known. Here, we report new material of Olonbulukia tsaidamensis, which was a member of this stem caprine assemblage, from the Wuzhong region, northern China, confirming similarity of the Wuzhong Fauna and ‘Qaidam Fauna’. Based on a metric study of horncores from the ‘Qaidam’ and Wuzhong faunas, we recognized six taxa from this stem caprine assemblage: Olonbulukia tsaidamensis, Olonbulukia sp., Qurliqnoria cheni, Tossunnoria pseudibex, ? Protoryx cf. enanus, and cf. Pachytragus sp. Among these taxa, Qurliqnoria and To...