Cockburn Island is one of the most historically significant places on the Antarctic continent. The isle was first surveyed in early 1843 during Captain James Ross famous expedition, but the early explorers failed to recognise its geological and palaeontological significance. Cockburn Island is exceptional for it has the only succession of Upper Cretaceous, Eocene and MiocenePliocene rocks on the continent, which is now known to contain an admirable and diverse fossil record of fauna and flora. These fossil assemblages are providing exciting new information on the evolutionary history of Antarctica. At least 22 species of Late Cretaceous macroinvertebrates and vertebrates have been recognised, whereas the Eocene record is slightly more diverse at 28 macroinvertebrate taxa recorded. The Pliocene macrofossil record is depauperate atsome 11 species, butmicrofossils (diatoms, ostracods, foraminifera) are represented by at least 94 taxa. The palaeoecologic and palaeobiogeographic significance of fossil assemblages is explored in this paper. Further, a checklist of fossils is presented herein, for the first time, as is a bibliography of the geology and palaeontology of the island.
This report describes aims and preliminary results of geological fieldwork carried out by a joint Argentine-Polish party on Seymour (Marambio) and Cockburn islands. Antarctic Peninsula, during austral summer of 1987 88. Seymour Island exposes chiefly shallow-marine, fossiliferous siliciclastic sediments that form an upper, 2000 m thick part in the Mesozoic-Tertiary backarc basin-infill of the Antarctic Peninsula. The fieldwork centered on paleontology and sedimentology of the La Meseta Formation (upper Eocene- ?lower Oligocene), although some observations of older deposits were carried out also. Clupeoid fishes were discovered in the La Meseta Formation. This is the first record of such fish fossils on the Antarctic continent.