Neogloboquadrina, Pulleniatina and Sphaeroidinellopsis-Sphaeroidinella Lineages in the Northern Indian Ocean: Their Paleoceanographic Relations and Biostratigraphic Significance

The evolutionary gradation and ancestor-descendant relationship within planktic foraminiferal lineages Neogloboquadrina, Pulleniatina and Sphaeroidinellopsis-Sphaeroidinella, from DSDP sites 214, 219 and 237 (Northern Indian Ocean) are discussed. The study suggests that the evolutionary diversification among these lineages are closely linked with the major oceanographic changes during the Neogene. The phyletic lineages are placed within chronologie framework in order to find out the reliability of vital taxa of these bioseries for biostratigraphic correlation.