Palynological study of the Punta del Barco Formation, lower cretaceous (Aptian) of Santa Cruz Province, Argentina. Systematic descriptions II: Apiculate, murornate, tricrassate and perinate trilete spores. Paleoecological implications

摘要

Eighteen species of disperse trilete apiculate, murornate, tricrassate and perinate spores from the Punta del Barco Formation, in the Meseta Baquero area, Lower Cretaceous of Santa Cruz Province, are described. They belong to the genera Gleicheniidites, Clavifera, Ornamentifera, Ceratosporites, Concavissimisporites, Staplinisporites, Retitriletes and Lygodiidites. Besides, a new genus for a perisporate spore -Capsispora- is proposed, an indeterminate apiculate form and two new species of the genus Gleicheniidites, are described. Finally, some paleoecological implications are given from the study of this spores association, which are related to stress conditions by the strong volcanic activity during the sedimentary deposition of this unit.