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Well-preserved and diverse Early Cretaceous palynological assemblages were studied from an outcrop section of the Springhill Formation at the Río Correntoso locality (PRC), close to Ghío Lake, in Santa Cruz Province, Patagonia, Argentina. The studied log corresponds to the northernmost outcrops known for the Springhill Formation in the Austral Basin. Most of the palynomorphs algae (Botryococcus, Sphaeroplea, Lecaniella, Zygnema, Pseudoschizaea, Schizosporis, Ovoidites), and some angiosperm pollen grains (Proxapertites , Longapertites, Arecipites) are distinctive and characterize the palaeoenvironment and palaeoclimate of PRC, which was dominated by estuarine coastal margin sedimentites deposited under warm and humid conditions. These angiosperm pollen grains correspond to the earliest record of these group in Patagonia, represented by diverse monosulcates and one rare tricolpate type. This new record of angiosperm pollen in the Springhill Formation provides further evidence that one of the earliest diversifications of angiosperms started at least during the early Cretaceous in Patagonia. Sergio Archangelsky provided an invaluable expertise in the field of paleobotany in multiple ways. His knowledge transcended not only through his papers but also through his exceptional oratory skills. His talks were always enriching in every aspect, combining an engaging historical account with a vision towards the future. "...La paleobotánica un placer, debe ser algo agradable, es decir uno cuando trabaja en paleobotánica le gusta lo que hace, y cuando uno está describiendo, uno se va, y es lo mismo que componer una pieza musical, te perdés, te perdés en todo y lo hacés con gusto, con pasión..." "...The paleobotany is a pleasure, it should be something enjoyable, meaning that when you work in paleobotany, you love what you do. And when you're describing, you get lost, just like composing a musical piece. You lose yourself, in everything, and you do it with pleasure, with passion...". The file with the voice of Sergio Archangelsky is in Supplementary file under Sergio_Archangelsky.mp3. • The palynoflora of the Springhill Formation includes algae and land plants. • Pollen records show features of early members of some taxa (monocots and eudicots). • Angiosperm pollen grains provides evidence for early radiation of some basal taxa in Patagonia. • Palynoflora studied indicates freshwater palaeoenvironment, warm and humid climate. [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]

Abstract: The araucarian pollen grain Cyclusphaera radiata Archangelsky is emended based on newly discovered material from the Piedra Clavada Formation of Albian age in Santa Cruz province, Argentina. The general morphology and ultrastructure of the pollen were studied by means of transmitted light, scanning, and transmission electron microscopy. C. radiata is discoid with an equatorial thickening and two large opposite apertures, with radial thickenings in one of them and two central apertural occlusive opercula-like structures. Beneath there is a thick amorphous electron-dense nexine. The combination of characters seen in this pollen type is very unusual, and no parallels are known in fossil or extant gymnosperm grains. Functional interpretation of the apertural exine suggests that the radial thickenings and apertural membranes were involved in harmomegthy, the opercula-like structures in germination, and the apertural nexine perhaps as a strengthening layer. A hypothetical pollination mechanism is also presented for C. radiata. The paleobiogeography of this taxon shows that during the Mesozoic, the plants that produced these grains inhabited an extensive area of Gondwana that included South America, Africa, India and Antarctica. [Copyright &y& Elsevier]