Aptian ferns with in situ spores from the South Shetland Islands, Antarctica

Compressions and impressions of fertile fern foliage occur in the Cerro Negro Formation (Early Aptian), South Shetland Islands, Antarctica. Some of them are fronds at least tripinnate, bearing rounded pinnules with sori containing annulate, stalked sporangia. The recovered spores are of the Cyathidites-type, with scattered foveae. These specimens are referred to a new genus and species: Eocyathea remesaliae gen. et sp. nov., confirming the presence of the Cyatheaceae in the area during the Early Cretaceous. Other specimens have elongate and lobed pinnules, usually falcate, bearing one sorus per lobe. Sori with stalked, annulate sporangia bearing spores of the Cyatheacidites-type. These are referred to Sergioa austrina gen. et sp. nov., and point to diversity in the family Lophosoriaceae or related groups during the Cretaceous.