Taxonomy, stratigraphic distribution and palaeobiogeography of the Early Cretaceous coral genus Holocystis

  • Hannes Löser Estación Regional del Noroeste, Instituto de Geología, Universidad Nacional Autónoma de México, Apartado Postal 1039, 83000 Hermosillo, Sonora, Mexico.
Keywords: Scleractinia, Cretaceous, taxonomy, corals, palaeobiogeography.


The Early Cretaceous Scleractinian coral genus Holocystis Lonsdale, 1849 – first reported for southern England and for a long time believed to be restricted to this region– is easy to recognise but it is also rare. Abundant material from the Late Barremian to Early Albian found in Sonora (Mexico) as well as the available type material and additional material from Europe and East Africa allowed a systematic revision. Five species are distinguished. One of them –Holocystis nomikosi– is described as a new species. Three species previously described for other genera were assigned to the genus Holocystis and two species formerly assigned to Holocystis were found to belong to other genera. Two genera (Tetracoenia and Nowakocoenia) are considered junior synonyms of Holocystis. The stratigraphic extent of the genus was limited to the range from the Barremian to the Early Albian. Holocystis is not a common coral genus but occurred in a large geographic area comprising the central Tethys, the Caribbean, and even the eastern to south-eastern Tethys. The genus is restricted to sediments with a certain terrigenous input.