Morphometric analysis in the shells of the planktonic foraminifera Orbulina universa: a source for paleoceanographic information?

Abstract In this study, we describe morphometric analyses of Orbulina universa morphotypes presently found in the Western South Atlantic, and their relation to the upper water thermohaline indexes. We also investigate this relationship under glacial and interglacial conditions between 7.2 and 32 kyr BP. Ten plankton samples distributed between 32º55' and 26º20'S were selected for the analyses of modern O. universa specimens. Core SIS188 was retrieved at 29º22’S, 47º28’W enabling the analysis of 21 fossil samples. Shell diameter, pore diameter, pore density and porosity were measured us...