An Introduction of <em>Globorotalia </em>(<em>Turborotalia</em>) Oceanica Cushman & Bermudez, 1949 in the Modern Ocean

To assess the validity of Globorotalia (Turborotalia) oceanica Cushman and Bermudez, 1949 in the Holocene four samples from the tropical Atlantic Ocean and Caribbean Sea, currently referred to Truncorotalia crassaformis, are analysed with procrustes transformed data for their integrity as representatives of local populations. While axial shape is weakly globose, it is highly variable and is related terminal growth of specimens and the depth at which samples were taken. The outline profile of late-formed chambers commonly forms a smooth curve, but mal-formed terminal chambers are often compressed at the periphery. There is only incipient formation of a keel at the periphery. The shape of the holotype falls centrally in the joint scatter of the four samples. The relation of these Holocene samples to Truncorotalia crassaformis is evaluated from a comparison of Holocene tropical Atlantic samples with one from the warm subtropical Southwest Pacific. The conical axial profile of the latter specimens, usually with a keel at the compressed periphery, resembles the neotype of Truncorotalia crassaformis. They are strongly discriminated from the Holocene tropical Atlantic samples of Truncorotalia oceanica which is judged to be a valid morphospecies in the modern tropical Atlantic Ocean and Caribbean Sea. The close similarity of the axial profile of late-formed chambers of early Pliocene specimens with modern counterparts is demonstrated.