Distribution of Calcareous Dinoflagellates in Cenozoic Sediments of Site 366, Eastern North Atlantic

Abstract

Paleocene to Pleistocene calcareous dinoflagellates in samples from DSDP Leg 41, Site 366 on the Sierra Leone Rise in the eastern North Atlantic are described using scanning electron microscopy (SEM). Two new species of Thoracosphaera were encountered. One species is rejected representing a diagenetically altered modification. Several species are described and illustrated for the first time by SEM examinations. The stratigraphic distribution of individual species described here shows restricted ranges, although a few long-ranging species are present. More complete investigation of regionally widespread material may result in using calcareous dinoflagellates as valuable index fossils.