Fig. (2) Stratigraphic distributions of selected Neogloboquadrina species from Site 1150. Broken lines indicate samples yielding less than 100 specimens of total planktic foraminifera. Magnetostratigraphic and tephrostratigraphic events and the Pliocene/Pleistocene boundary are taken from Kanamatsu and Niitsuma [4] and Motoyama et al. [2]. The top of Chron C2n (Olduvai) is not present at Site 1150 [4]. The arrow indicates the Aso-4 tephra horizon [2].