Two samaras of Rhamnaceae from the middle Miocene of southeast China

Rhamnaceae was widespread over the Northern Hemisphere during most of the Cenozoic. Abundant fossil materials play an important role in evaluating divergence times, which aids in understanding the morphological evolution and biogeographic histories within the family. Two occurrences, Paliurus hirsuta J.L. Dong et B.N. Sun sp. nov., and Ventilago lincangensis K.N. Liu et S.P. Xie, are presented here from the middle Miocene of Zhangpu County, South Fujian Province, based on diagnostic winged fruits. The morphological and anatomical features of the two species are described in detail. The fossil records of Ventilago are rarely documented, and our discovery adds new information to understand the history of this genus. Paliurus hirsuta sp. nov. fruits are pubescent which show a closer affinity to the P. ramosissimus group. As a result, we deduce that Paliurus probably had differentiated into two groups in low latitude South Fujian by the middle Miocene. Fossil assemblages presented in the Fotan flora indicate that a diverse forest flora surrounding a lake or wetland in Zhangpu County, Fujian Province, during the middle Miocene.