Acropora (Scleractinia) from the Oligocene and Miocene of Europe: species longevity, origination and turnover following the Eocene–Oligocene transition

Four new species and new records for six species of the highly successful reef-building coral genus Acropora are described from Oligocene and Early Miocene (Rupelian to Burdigalian) localities in Europe. Acropora slovenica sp. nov. is described from Slovenia (Gornji Grad beds); A. piedmontensis sp. nov. and A. macrocalyx sp. nov. from the Torino Hills (Piedmont), and A. salentina sp. nov. from the Salento Peninsula (Apulia) of Italy. The remaining six species have an Eocene lineage. From south-west France, A. anglica and A. bartonensis, previously known from England (Priabonian and Bartonian), are recorded: A. anglica in Oligocene (Chattian) and both in Miocene (Aquitanian) deposits, indicating their persistence in the western Tethys for up to 17 and 20 million years respectively. Also recorded from Aquitaine is A. wilsonae (type locality Eocene Paris Basin), indicating persistence in western France for up to 28 million years. Italian material includes A. proteacea, also known from the Lower Bartonian of France and A. lavandulina, already known from Italy and the Eocene of France. From Slovenia (Oligocene, Rupelian), A. haidingeri is recorded, including from the type locality. The species are interpreted as representing seven extant species groups previously documented from the Eocene of Europe and the first records for two further extant groups. These results complement a previous finding of Eocene diversification of Acropora into the beginnings of up to 10 of the 20 recognized modern species groups in England and France. They indicate that the longevity of some Eocene taxa was extended into the Oligocene to Early Miocene of Europe and allowed some turnover, probably associated with changes in configuration of the western Tethys Sea. This information is important for interpreting molecular phylogenies and the evolution of modern Acropora diversity, by providing extended stratigraphical ranges for species groups with Eocene origins and dates of origination for two groups previously unrecorded in the early fossil record.