New species and records from the Eocene of England and France support early diversification of the coral genus Acropora

Five new species of the highly successful reef-building coral genus Acropora are described from Eocene locations in England and France (Acropora britannica, A. alvarezi, A. wilsonae, A. bartonensis, and A. proteacea) and additional records are given for six fossil species (A. deformis, A. anglica, A. solanderi, A. roemeri, A. lavandulina, and A. ornata), based on re-examination of material in the collections of the Natural History Museum, London. Specimens came from the Lutetian (49.0 to 41.3 Ma) of France, Bartonian (41.4 to 37.0 Ma) of England and France and Priabonian (36.0-34.2 Ma) of England. Included are the earliest record of a species with tabular or plate-like colonies similar to those in the modern "hyacinthus" species group (A. proteacea n. sp.) and the earliest records of simple hispidose forms (A. bartonensis n. sp. and A. roemeri), similar to those in the modern "florida" species group. The Priabonian material from southern England (A. brittanica n. sp. and A. anglica) shows the earliest occurrence of two sturdy species groups, the "humilis II" and "robusta" groups respectively, which now occur together on reef fronts throughout the modern Indo-Pacific. The new descriptions and records contribute to evidence that the genus diversified rapidly after its appearance in the fossil record. This diversification may have contributed to the rapid speciation and dispersal, observed in this genus during the Neogene, culminating in its extraordinary dominance of modern Indo-Pacific reefs.