The Cenozoic hermatypic corals in the eastern Pacific: History of research

Studies of hermatypic corals in the eastern Pacific have mainly focused on Recent species, and relatively few of these works have studied fossil corals. The purpose of the present contribution is to provide a comprehensive synthesis on Cenozoic hermatypic coral studies that will serve: a) to identify gaps in our understanding about the Cenozoic evolution of eastern Pacific hermatypic fauna, and b) to be used as a baseline for future work in the region. Our knowledge regarding the eastern Pacific fossil coral fauna has increased gradually since 1864. A total of 151 coral species including synonyms have been recorded in the region. The species richness increases from Paleocene to Oligocene followed by a loss of species towards the Pleistocene, though to some extent biodiversity estimates are affected by sampling intensity. Fossil-bearing units are spatially restricted to Washington-Seattle, south and central California, Gulf of California and Chiapas, and there is a lack of outcrops in western México and Central America. In general, fossil coral studies have been sporadic, incidental in nature, and restricted to species descriptions, faunal lists and geographic affinities. The relative lack and nature of the hermatypic fossil studies in the region have directly affected our understanding about the origin of the modern eastern Pacific coral fauna and its evolutionary history. Studies regarding to taxonomy and systematics, and detailed spatio-temporal community dynamics, are essential for understanding the evolution of the fauna.