A reconsideration of the diversity of Symplocos in the European Neogene on the basis of fruit morphology

A taxonomic reassessment of Symplocos from the Neogene of Europe is proposed based on morphological and anatomical features of fruit stones at the macro- and mesoscopic scale. In light of the large extent of polymorphism observed in fossil and recent stones, we dramatically reduced the number of species in the European Neogene. Only 11 out of 26 fossil species cited in the literature of the last two decades were still considered valid, and, due to the species concept we applied, we suggest that this number roughly corresponds to the number of ancient botanical species which actually grew in the lowlands of Europe from 30 to 2 My ago. The characters of the valid species are extensively illustrated to provide a guide for species identification. An updated overview of the stratigraphic and geographic distribution of the species of the European Neogene is also provided. A comparative analysis of fossil fruits and analogous modern material (poorly available) has been carried out with the aim to derive climatic information from modern plants.