Paleogene marine ostracodes from the south-southeast of Lake Cardiel, Santa Cruz, Argentina

Twenty-two genera and thirty-eight species of Palaeogene marine ostracods from the San Miguel profile and West Estancia San Miguel and (Eocene?) West Estancia San Miguel samples of Centinela Formation, from the southeastern region of Lake Cardiel, Santa Cruz Province (49 degrees 15' S, 71 degrees 05' W), were studied. They are not well preserved. Nineteen taxa were described previously. Nine species are provisionally classified. Wichmannella deliae Bertels and Australicythere sp. 1 are the dominant species. The microfauna seems to have inhabited a shallow sea having a warm-temperate palaeotemperature, relatively rapid sedimentation, moderately high energy level and high oxygen level. Magnesium would be the most abundant cation. The ostracods of the San Miguel profile and West Estancia San Miguel sample are assigned to the Oligocene according to geological and foraminiferal data.