A new species of Pliopithecus from the middle Miocene of China and its implications for early catarrhine zoogeography

Eight cranio-dental specimens of a small catarrhine primate have been recovered recently from the locality of Maerzuizigou and nearby sites in Tongxin County, Ningxia Hui Autonomous Region, northcentral China. This area has yielded a diverse mammalian fauna which is estimated to date to about 15 m.y.a. (early Tunggurian, Faunal Unit I), broadly comparable to the Sansan and Byelometchetskaya local faunas of Europe (early Astaracian, MN 6). The present study has confirmed the initial assessment of Qui & Guan (1986) that the primate material should be referred to Pliopithecus. It is generally similar to Pliopithecus from Europe, but differs from the three currently recognized species in being considerably larger in size and in the details of its dental morphology. On the basis of these differences, there is sufficient evidence to recognize a new species of Pliopithecus. The new species confirms that the pliopithecids extended their range eastwards into Asia during the early middle Miocene soon after their earliest appearance in Europe. The diversity of pliopithecids in Eurasia at this time suggests that the initial migration may have involved multiple species derived from a diverse community established in Africa prior to their arrival in Europe. The distribution of early pliopithecids and Eurasian proconsulids during the middle Miocene indicates that the two groups may have occupied geographically and ecologically distinct provinces. The pliopithecids in China document two episodes of faunal contact between Europe and Asia during the Miocene.