Late Cretaceous larger rotaliid foraminifera from the westernmost Tethys

Abstract

A detailed taxonomical study of the larger rotaliid foraminifera found in the Upper Cretaceous deposits from the External Prebetic Zones (SE Spain) has been carried out for the first time. The study of the samples has revealed the diversity and abundance of this foraminiferal group and its usefulness as a tool for regional biostratigraphy. Five new species and two new genera are described, Pseudosulcoperculina bocairentina gen. et sp. nov., Plumopraelockhartia solanensis gen. et sp. nov., Rotalia baetica sp. nov., Suturina minima sp. nov., and Neorotalia? pinetensis sp. nov. These and other species of larger benthic foraminifera have been found forming two different assemblages. The older assemblage, dated as middle to late Campanian, is composed of the rotaliid species N.? pinetensis sp. nov., R. baetica sp. nov., Suturina globosa, Rotorbinella sp., Pararotalia tuberculifera and Rotalispira scarsellai. The younger assemblage is dated as late Maastrichtian, including the rotaliids Pseudosulcoperculina bocairentina gen. et sp. nov., Plumopraelockhartia solanensis gen. et sp. nov. and Pararotalia tuberculifera. In global terms, the Late Cretaceous rotaliids from the Prebetic are key in our understanding of the phylogenetic relationships among the Cretaceous and early Paleocene Tethyan species, allowing to root the origin of the lockhatiines sensu lato back to the Upper Cretaceous. Besides, the new data regarding the Sulcoperculina-like forms have revealed the differences and similarities among the species of both sides of the Atlantic, especially, between the architecture of the American genus Sulcoperculina and that of similar forms in Pyrenean and Tethyan realms, grouped into new a genus here introduced as Pseudosulcoperculina.