Ostracod provincialism and migration as a response to movements of Earth's plates: Cretaceous-Paleogene ostracods of West Africa, North Africa and the Middle East

Abstract

This paper documents the Cretaceous –Paleogene ostracods response as the continental plates tend to show divergence. For example, in the intervals from the Early to Late Cretaceous when the South American plate tended to exhibit divergent movement westward from the African plate, the migration of ostracods show westward trend from Northeast Africa to West Africa; whereas, the divergence of the Indian and the Australian plates as well as the Antarctic plate from the African and the Eurasian plates, and Arabia is accompanied with ostracod migration southward. Another example from the Maastrichtian-Eocene ostracods of West Africa, where ostracods exhibit east-west migration (despite the migration of epineritic ostracods in both directions; east-west and vice-versa) towards the North American and South American plates. These trends of migration towards the deep oceans (Atlantic and Indian oceans of present time) indicate the tendency of ostracods of these geologic times towards endemism in the deep oceans resulted from seafloor spreading during the divergence of the continental plates. On the other hand, the paleoenvironmental changes should also have significant effect on these trends of migration.