Taxonomy and palaeoceanographical significance of the genus Krithe (Ostracoda) in the Brazilian margin

Abstract. The results of taxonomic, geographical distribution and palaeoecological studies of the genus Krithe from the Brazilian continental margin are presented. The following species and subspecies are recognized: Krithe reversa Bold, 1958; K. trinidadensis Bold, 1958; K. morkhoveni morkhoveni Bold, 1960; K. coimbrai sp. nov.; and K. gnoma sp. nov. Four species are left in open nomenclature. The occurrence of Krithe within the Brazilian continental margin is restricted to areas under the influence of cold waters and, considering their stratigraphic distribution in Cenozoic strata, they are here recognized as being useful as palaeoceanographic indicators. Of the above-mentioned species, only two occur within the Brazilian continental shelf; these are K. coimbrai and K. gnoma. These species are eurybathic and their occurrences in a shelf environment are restricted to areas under the influence of the Falkland Current. Considering their stratigraphic distribution within the Pelotas Basin, southern Brazil, and their association with other cold-water taxa, including species of foraminifera, it is here suggested that the Falkland Current was already operating in the Miocene.