Regional persistence of the extant coral genus Stephanocoenia since the Early Cretaceous in the Western Atlantic

Abstract

The scleractinian coral genus Stephanocoenia was previously only known from the Western Atlantic with two Pliocene and two extant species, of which two are considered synonymous. Systematic sampling and examination of collection material revealed that the genus occurs from the Hauterivian to extant with gaps in the fossil record during the Campanian, Paleocene and Eocene. During this time the genus was restricted to the Western Atlantic and is unknown in other areas with the exception of one specimen from the Maastrichtian of the eastern Pacific. Thirteen species are separated using non-parametric statistical methods. Two species are described as new. One species remained in open nomenclature and two species can only be compared to existing species. The genus reached its highest abundance during the Early Albian with five species and the Pleistocene/extant with four species. Stephanocoenia demonstrates a regional persistence unchanged over the past 135 million years, which is unique among all post-paleozoic scleractinian corals. Stephanocoenia is also the most ancient hermatypic scleractinian coral genus, which still exists today.