A new Celastrus species from the middle Miocene of Yunnan, China and its palaeoclimatic and palaeobiogeographic implications

• We report a new species of Celastrus with serrate theoid teeth with clear, deciduous setae.
• Based on the nearest living relative approach, Zhenyuan had a warmer and more humid climate in the Middle Miocene.
• A transpacific dispersal of plant possibly occurred between East Asia and Central America.

Leaves of a new species of Celastrus L. (Celastrus caducidentatus Liang XQ et ZK Zhou) are described from the middle Miocene of Zhenyuan, China. They have serrate theoid teeth with clear, deciduous setae and pinnate venation. The species is closely related to Celastrus paniculatus ssp. paniculatus and probably belongs to subgenus Celastrus series Paniculati. According to the nearest living relative approach, its presence suggests that Zhenyuan had a warmer and more humid climate in the middle Miocene and that ancestors of C. paniculatus probably occurred in East Asia. The distribution history of the genus shows that the North Atlantic corridor and/or Bering continental bridge played an important role in the migration between North America, Europe and Asia. The affinity between C. caducidentatus and Celastrus pringlei Rose, which is only distributed in Mexico, suggests that a transpacific dispersal existed between East Asia and Central America.