EARLY CRETACEOUS FERN FOLIAGE FROM PRESIDENT HEAD, SNOW-ISLAND, ANTARCTICA

Fertile fern foliage described as Lophosoria cupulatus so. nov, contai ns the distinctive spore Cyatheacidites annulatus. The fossil foliage is morphologically similar to the Early Cretaceous form-genera Gleiche nites and Microphyllopteris, whose time and space distribution in Gond wana matches that of the dispersed spore Cyatheacidites. Some of the C retaceous southern hemisphere material assigned to Gleichenites and Mi crophyllopteris is probably allied to families such as the Lophosoriac eae rather than the Gleicheniaceae as had been previously supposed. Th e nearest living relative, Lophosoria quadripinnata, grows within a me an annual temperature range of 8-22 degrees C, and a mean annual preci pitation range of 195-1977 mm. The presence of Lophosoria cupulatus at palaeolatitudes of 55-65 degrees S implies that during the Aptian the southern high latitudes were a minimum of 12 degrees C warmer than th e present day.