Abstract. Detailed study of the Palaeocene Morozovella lineage of Deep Sea Drilling Project Sites 577 (Shatsky Rise, North Pacific) and 527 (Walvis Ridge, South Atlantic) have revealed a distinct morphological stage transitional between M. angulata (White) and M. velascoensis (Cushman & Ponten). This stage is characterised by the development of the first peripheral pseudo-keel of the Cenozoic Globigerinidae and is named Morozovella protocarina. The biostratigraphic application of this species clarifies problems of recognising the Late Palaeocene planktonic foraminiferal zones.
Summary of Cretaceous/Tertiary Boundary Studies, Deep Sea Drilling Project Site 577, Shatsky Rise