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Pollen tetrads and monads of spiny pollen grains with close affinities to palms have been found in several localities from the Lower Cretaceous (Barremian-Albian) of the Austral Basin (Magallanes), Patagonia (Argentina). When found dispersed, spiny and zonasulcate pollen grains, are commonly referred to the fossil genus Spinizonocolpites Muller, with close affinities to the extant palm Nypa . The Patagonian specimens were compared with fossil and extant members of the Arecaceae, showing close similarities in shape and sculpture with the primitive members of the subfamily Calamoideae. Nypa produces tetragonal tetrads different from the tetrahedral tetrads of the Spinizonocolpites -type recovered from Patagonia. The specimens were studied with LM and SEM. The polarity, aperture orientation and tetrad type allow segregating the Patagonian grains from the Nypoideae and relating it to the Calamoideae subfamily. These records suggest an antique origin of monocots and a probably initial diversification of calamoid palms during the Early Cretaceous in high latitudes of Gondwana. The presence of palmae during the Early Cretaceous in southern South America suggests a warm and humid climate, similar to that found in present days at tropics. [ABSTRACT FROM AUTHOR]

Abstract: A palynological review of cingulate spores having affinities with the fern family Pteridaceae found in Lower Cretaceous assemblages of Patagonia, Argentina, is presented. The new genus Sotasporites, with three species is defined: S. triangularis sp. nov., S. elegans (Archangelsky and Gamerro) comb. nov. and Sotasporites sp. Comparisons with spores of extant members of the family show close similarities in shape and sculpture with the products of taxa living in the southern Andes. Muricingulisporis annulatus Archangelsky and Gamerro, originally defined from the Aptian Baqueró Group of Patagonia, is maintained in its original combination after the revision of the types. The differences from Cyatheacidites of the family Lophosoriaceae, to which this species was assigned elsewhere, are underscored. Finally, three species of Contignisporites, viz. C. cooksoniae (Balme) Dettmann, C. glebulentus Dettmann and C. burgeri Filatoff and Price are described and reviewed. It is concluded that the Pteridaceae played an important role in Patagonia and were represented by several taxa during the Early Cretaceous. [Copyright &y& Elsevier]

Araucaria grandifolia Feruglio is emended based on new material, with cuticle preserved, found at the type locality within the Punta del Barco Formation, Lower Cretaceous of Santa Cruz Province. The morphology of the leaves, secondary xylem of the branches and cuticular analysis as seen under light and scanning and transmission electron microscopes allowed comparison of this taxon to living and fossil members of the Araucariaceae. It is confidently placed in Araucaria, section Columbea. Three of the four sections of Araucaria, with the exception of Intermedia, are represented in the fossil record of Patagonia. The Bunya section is already present in the Jurassic and theColumbea and Eutacta sections are registered from the Cretaceous. Columbea is the only section that survived in the form of two living species. Lectotypification of the original material is also proposed. [Copyright &y& Elsevier]