EARLY DEVONIAN TAPHOFLORA RECORD IN PONTA GROSSA ARCH, PARANA BASIN (SOUTHERN BRAZIL) AND ITS PALAEOGEOGRAPHIC IMPLICATIONS

This work analyzes the taphofloras collected from two Lower Devonian localities (PISA and Ponta Grossa/Carambei) of the eastern border of the Parana Basin (Southern Brazil). This association is of late Lochkovian age. It includes a large number of records of Cooksonia paranensis Gerrienne et al., 2001, as well as of other taxa representative of this age interval. The occurrence of these plants in the Parana Basin raises questions related to the Early Devonian paleoclimatic and paleogeographic settings, mainly when compared with the coeval floras from Bolivia and Laurasia. According to the most recent paleogeographic reconstructions, the Parana Basin was located very close to the South Pole during Early Devonian times and was under cold climatic conditions and poor insolation or even darkness during long periods. Some Brazilian primitive plants possess spine-like emergences, which may indicate protection against cold climatic conditions and desiccation and/or an attempt to increase photosynthetic surfaces. The existence of such diversified taphofloras close to the South Pole during the Early Devonian corroborates the hypothesis of an ice-free pole at this time, which allowed the development of vegetation in terrestrial environments. The taphofloras of the Parana Basin are strikingly similar to those of probably coeval localities from Euramerica. The implications of these similarities are discussed in a paleogeographic context in this work.