A leafy branch with attached fruit cups from Late Miocene deposits of France provides new insights into the evolution of Cerris oaks (Quercus sect. Cerris)

Plant fossils offer crucial information about the evolutionary history of various plant lineages. However, the precise systematic position of fossil-species and relationship with extant taxa are difficult to establish because fossils are usually preserved as isolated elements lacking organic connection. Oaks (genus Quercus) are particularly problematic due to widespread convergent trait evolution. Here, we describe a new fossil-species based on a leafy branch with attached fruits from the Late Miocene of southern France. Quercus bernardii sp. nov. closely resembles the eastern Mediterranean endemic Q. look, sister species to the widespread western Eurasian Q. cerris and Q. castaneifolia of the southern Caspian Sea shores, which together form Q. subsect. Cerris. Quercus bernardii shares leaf characteristics with Q. cerris and Q. look, whereas the lack of persistent apical stipules in the buds and the reduced cup scales link it with Q. look. The age of the fossil and a previous dated phylogeny suggest that species lineages in Q. subsect. Cerris started to differentiate in the Late Miocene. Previous palaeoclimate estimates suggested a humid, mild climate for the fossil-species. Similar climates are still encountered in the habitats of extant Q. cerris, whereas Q. castaneifolia and Q. look thrive in relict areas with stronger precipitation seasonality. Citation: Denk T., van Zuijlen K. & Krings M. 2026: A leafy branch with attached fruit cups from Late Miocene deposits o France provides new insights into the evolution of Cerris oaks (Quercus sect. Cerris). – Willdenowia 56: 249–267. Version of record first published online on 1 May 2026.