Coniopteris antarctica sp. nov. (Pteridophyta) and associated plant assemblage from the Upper Cretaceous of Rip Point, Nelson Island, Antarctica

Fossil plants are reported from beds exposed on northern Nelson Island, South Shetland Islands. The fossiliferous beds are exposed near sea level and constitute the basal intervals of sedimentary succession at Rip Point. The low diversity macrofossil assemblage contains only charcoalified woods and isolated fern pinnae. However, the palynoassemblage from the same beds contains typical Antarctic Late Mesozoic pollen and spores of Nothofagus, conifers, ferns and fungi. The sterile and probable pteridophytic remains are assigned to the Coniopteris. The dark tuff lithologies, with evidence of alteration and recrystallization, and similarities between the fossil assemblage and others in the Antarctic Peninsula support a Late Cretaceous age. The persistence of Coniopteris until the Late Cretaceous in Antarctica compares with its range in Northern regions and follows its cosmopolitan distribution during the Jurassic its patchy distribution at the end of the Cretaceous is indicative of persistence in moist, cool, high latitude refugia, especially in insular environments, before its final extinction.