Endocarps of Prunus (Rosaceae: Prunoideae) from the early Eocene of Wutu, Shandong Province, China

Endocarps of the genus Prunus (family Rosaceae) have been described from early Eocene clay deposits in the Wutu Coal Mine, Shandong Province, China. Endocarps are elliptical or ovoid in lateral view, with a long canal that approaches the apex of the endocarp and contains the ventral vascular bundle. Comparisons with related living and fossil species of Prunus indicate that these endocarps should be assigned to Prunus wutuensis sp. nov. The endocarps from Wutu represent the earliest record of Prunus in Asia. Based on the distribution of fossil Prunus endocarps, the palaeobiogeographic history of the genus is shown on palaeogeographic maps of the Northern Hemisphere. The fossil data suggest that the genus first appeared in the early Eocene of North America and Asia, and then extended to Europe in the middle Eocene.