Upper Pennsylvanian lycopsids from interglacial taphoflora of Itararé Group, Paraná Basin, Brazil

Abstract

The Pennsylvanian strata of the Itararé Group are present on the northeastern border of the Paraná Basin, i.e. northern part of Paraná State towards north of São Paulo. The Pennsylvanian lycopods of the Itararé Group are represented by diverse megafossils, megaspores and microspores. The present study deals with the lycopsid megafossils from the third interglacial level of the paleofloristic succession of the Itararé Group in the northeastern border of the Paraná Basin, i.e. Paranocladus-Ginkgophyllum-Brasilodendron association (PGB as.) recovered from its type locality Volpe ranch, in Monte Mor municipality, SP. The megafossils belong to the taxa Bumbudendron millani, Bumbudendron cf. B. paganzianum, Brasilodendron pedroanum, Brasilodendron sp., Leptophloeum cf. L. sanctae-helenae, and Cyclodendron sp. The diversity and abundance of the megafossils (sometimes forming coal beds in a glacial context) indicates climatic ameliorations of an interglacial phase of the “time Itararé”. They represent paleoecological hydrohygrophyllous communities of a fluviatile-lacustrine depositional environment. The biostratigraphical distribution of these taxa and their association with Paranocladus, Ginkgophyllum and Buriadia suggests a paleofloristic correlation with the Krauselcladus - Asterotheca Phytozone of northwestern Argentinean paleofloristic zonation. The lycophytic megaspores recorded earlier from this level suggest a diachronic correlation with the Permian Talchir and Karharbari associations of Indian Gondwanan flora. Comparison with late Paleozoic lycopsids and associated megaspores of Argentina and India are in consonance with the modern studies aiming to achieve knowledge of Gondwana biostratigraphy in a wider perspective.