A new cycad trunk from the Palaeocene in the Neuquén Basin, Patagonia (Argentina)

To date only two genera of cycad stems have been described from Cenozoic strata (Bororoa and Menucoa). We describe a new species of Wintucycas, Wintucycas beatrizae sp. nov. (Encephalartoideae), from the basal Palaeogene of Patagonia. The new species is based on anatomically preserved mature cycadalean stems which have been recovered from the Pichaihue Limestones (Neuquén Basin, Patagonia, Argentina). The new species is characterized by the presence of a columnar stem with an armor of persistent leaf bases, vascular bundles displaying an omega pattern, the absence of cataphylls, a wide pith with medullary vascular bundles, mucilage canals and idioblasts, a polyxylic vascular cylinder, inverted xylem, and manoxylic wood. The presence of W. beatrizae sp. nov. in the Pichaihue Limestones suggests warm climate conditions during the early Palaeogene in the Neuquén Basin, and also extends the range of this genus of Cycadales (Encephalartoideae) into the Cenozoic.Fil: Martinez, Leandro Carlos Alcides. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Ottone, Eduardo Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Artabe, Analia Emilia Eva. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentin