Palaeo-climatic and -biogeographical implications of Oligocene Ostracoda from CRP-2/2A and CRP-3 drillholes, Victoria Land basin, Antarctica

A total of eighteen species of marine ostracods, in at least twelve genera, have been recovered from Early and Late Oligocene glacio-marine sediments from boreholes CRP-3 and CRP-2/2A in the Victoria Land Basin, Ross Sea, Antarctica. Faunas are sparse and generally moderately-well preserved. Previously, three species or closely related species have been recorded only from glacial settings (Kuiperiana meridionalislain (Müller), Australicythere polylyca (Müller), Hemicytheridea aff. H. kinggeorgeensis Blaszyk), but palaeotemperatures somewhat higher than at present in the Ross Sea are suggested by the presence of Austrocythere reticulotuberculata Hartmann, Cluthia aff. C. antiqua Ayress & Drapala and Cytherella? sp 4796. Majungaella sp. 4471 is an enigmatic component, representing a genus previously known only from warm Cretaceous and Eocene, and relatively warm interglacial Pliocene habitats in southern Gondwana and the Antarctic Peninsula. Palaeobiogeographical considerations indicate that during Early Oligocene times, the Ross Sea area had faunal links with both Antarctic Peninsula/South America and southern Australasia. Three species present in the Early Oligocene glacial environments at Cape Roberts have survived to the Recent in the cool-cold Antarctic/Sub-Antarctic region: Austrocythere reticulotuberculata Hartmann, Australicythere polylyca (Müller), and Kuiperiana meridionalis (Müller)