Palynology of the Baqueró Group (upper Aptian), Patagonia Argentina: An integrated study

Abstract

A palynological study on samples obtained from the Anfiteatro de Ticó and Punta del Barco formations (Baqueró Group, Macizo del Deseado area, Santa Cruz Province) is carried out. A total of 162 taxa are identified in this work, including the recognition of 59 not previously reported in the unit. Furthermore, 9 new species are proposed: Coptospora santacrucensis sp. nov., Crybelosporites corrugatus sp. nov., Cycadopites grossus sp. nov., Cyclusphaera annularis sp. nov., Cyclusphaera punnulosa sp. nov., Densoisporites patagonicus sp. nov., Peromonolites globosum sp. nov., Retitriletes ornatus sp. nov. and Taurocusporites inaequalis sp. nov. Continental algae, recovered from the Anfiteatro de Ticó Formation, are illustrated for the first time. Comparisons with other Lower Cretaceous palynological zones from regions located at similar paleolatitudes (e.g. Australia, India) and from the Potomac Group (USA) are carried out. Finally, changes in the floral composition across the Baqueró deposits are analyzed considering a context of progressive increase of volcanic activity that most certainly had some effect in the dynamics of the floristic community.