Paleoecological and paleobiogeographical inferences of the Paleocene ostracods from Sinai, Egypt

Abstract

The present study aims to detect the paleoecology and paleobiogeography of the Paleocene ostracods from Sinai, Egypt. In order to reach our goals, the Paleocene rocks were examined in four outcrops (El Dokh, El Qussaima, Matulla, and Ekma sections) from Sinai, Egypt. The recognized rock units include Dakhla Formation (at the base) and Tarawan Formation (at the top). The investigation of the ostracod fauna yielded 49 species and subspecies, which enabled the recognition of one Paleocene biozone, Mauritsina teiskotensis - Ordoniya ordoniya Zone. The Early and Middle Paleocene have diverse assemblages, while the Late Paleocene showed a rarity of ostracods. Based on the shape of the carapaces and the surface ornamentation, four ostracod morphogroups were recognized. Morphogroup 4 is the most common group in all the studied sections. The structure of ostracod assemblages (abundance, richness and the morphogroups) besides the lithology pointed out to middle - outer neritic depositional environment for the studied Paleocene sections. The identified species have a wide geographic range, extending from West Africa, North africa to the Middle East. The paleobiogeographic framework is carried out with the aid of multivariate analyses. The suggested matrix consists of 25 ostracod species from 10 countries, including Egypt, Libya, Tunisia, Algeria, Jordan, Israel, Senegal, Ivory Coast, Niger and Mali. The outcomes of the Q-mode cluster analysis indicate that the selected countries may be categorized into three provinces, North Africa (Libya, Algeria, Tunisia and Egypt), West Africa (Senegal, Mali, Ivory Coast and Niger), and Middle East (Israel and Jordan). The similarity of ostracod assemblages between North Africa, including Egypt, with that of Jordan and Israel, suggests the migration and exchange through the southern Tethyan coast. The common deep marine species between North and West Africa may be migrated along the West African coast on the Atlantic Ocean, while shallow species migrated through the trans-Saharan seaway.