Vitaceae seed and wood fossils from the Eocene–Oligocene phosphatic fissure fillings of Quercy, southwestern France

The phosphatic fissure fillings of Quercy span the Eocene–Oligocene transition (EOT) and contain anatomically preserved plant remains that provide critical data on local vegetation. However, unlike the vertebrate fauna, this material has not been examined through a detailed systematic study. The present study integrates seed morphology, wood anatomy, and quantitative morphometric analyses to investigate Vitaceae from Late Eocene to Late Oligocene deposits (European Mammal Paleogene reference levels MP18–MP25). Based on this combined approach, three new species are described. Two seed species are recognized: Vitis quercyensis sp. nov. (subgenus Vitis ), which is restricted to the Late Eocene, and Vitis praerotundifolia sp. nov. (subgenus Muscadinia ), which persists from the Late Eocene through the Late Oligocene. This provides the earliest evidence of subgenus Muscadinia in Europe and also demonstrate that diagnostic seed characters of Vitis had diverged by the Late Eocene. In addition, a fossil wood, Austrovideira barivierae sp. nov., from the Early Oligocene (MP22) is described based on twig material and interpreted as showing close anatomical affinity with extant genus Vitis . Collectively, the persistence of the thermophilic Muscadinia lineage and the presence of vitaceous wood imply that the Quercy region functioned as a refugium. It is inferred that multi-stratal forest structures, represented by tree-supported liana habitats and local wooded patches, persisted in Quercy, buffering some thermophilic lineages against the climatic deterioration associated with the EOT.