Paleoclimatic implications of a vascular plant from the lowermost Itararé Group

Abstract

Plant fossils serve as critical proxies for interpreting past climates and environments, offering insights into the history of biosphere and climatic conditions. Here we describe a large tracheophyte cast, as well as the sedimentological settings in which it is preserved, expanding the paleobotanical database of the Itararé Group and contributing to the understanding of the LPIA in the Paraná Basin. This fossil occurs in Ponta Grossa, Paraná state, Brazil, within sedimentary levels interpreted as glacially dominated and deposited during the Late Paleozoic Ice Age (LPIA). The plant macrofossil is preserved as a cast, and the log is vertically oriented with a slight inclination in relation to the bedding plane. Taphonomic data indicate an allochthonous preservation, suggesting that the log was transported from inland areas to a plain before final burial. The identification of the tracheophyte cast within these glacial beds suggests that even in a dominantly glacial context, there were periods of episodic climatic amelioration. This finding implies that the climatic conditions during the Mississippian were not uniformly harsh, allowing the growth of vegetation as represented by the reported tracheophyta.