Cenomanian-Turonian bivalves from eastern Sinai, Egypt

68 bivalve species belonging to 13 orders, 29 families, and 51 genera, are systematically described from three Cenomanian-Turonian sections (Gebel Areif El-Naqa, East Themed, and Wadi Quseib) on the eastern side of the Sinai Peninsula. The stratigraphic range and palaeogeographic distribution is given for each species. Nine species are reported from Egypt for the first time. Due to their taxonomic relevance, the microstructure of the rudist taxa has been illustrated. The bivalve fauna strongly resembles that of other Tethyan regions in southern Europe, North Africa, Middle East, and eastern South America. Therefore, most of the identified taxa have a strong Tethyan affinity. The distribution patterns of bivalves have probably been influenced by east-west directed currents during the Cenomanian. However, due to the presence of geographic barriers, extensive shallow marine shelf areas, and narrowing of the Tethys during that time, the current split up, one branch extending in a clockwise direction to southeastern Europe. The opening of the Trans-Saharan Seaway of southern Tethyan bivalves immigrated to western Africa and eastern South America.