Taxonomy and distribution of the Cretaceous coral genus Eosiderastrea

Abstract

The new genus Eosiderastrea Loser, 2016, was established for Cretaceous corals formerly assigned to the extant coral genus Diploastrea. It represents the oldest member of the Family Siderastraeidae. The genus is characterised by an astreoid arrangement, occasionally although some have a plocoid or a cerioid calicular arrangement, and a sub-regular hexameral, heptameral, octameral or decameral septal symmetry. The septal blades are made of medium-sized trabeculae. Synapticulae are present. Almost a hundred specimens were examined, among them numerous type specimens. In total, 26 Cretaceous species were separated. Fifteen species were assigned to formally established species, three species were compared to one of these species, two species were described as new and the remaining six species were reported in open nomenclature. The genus occurs in the Cretaceous worldwide and ranges from the late Valanginian to the Santonian. It shows its greatest diversity in the earliest Aptian and early to middle Cenomanian.