An oasis in Western Gondwana: A diverse Guadalupian paleoflora from South America

Abstract

The end of the Paleozoic Era was marked by intense climatic crises that not only annihilated much of the marine and terrestrial biodiversity but also acted as an evolutionary pressure, shaping the surviving lineages that thrived throughout the Mesozoic. The Guadalupian (Permian) is characterized by a gradual aridification, with the end of this epoch punctuated by a significant mass extinction event that profoundly impacted continental ecosystems. Guadalupian plant fossil localities are rare across Gondwana, usually preserving isolated material. In this study, we present a Guadalupian-aged outcrop in the southern Paraná Basin, Brazil, featuring a unique and remarkable taphoflora composed of a floristic association represented by different taxa: Lycopsida, Sphenopsida, Pteridospermae, Filicopsida, and Gymnospermae. This taphoflora not only represents an important record that broadens the paleoflora database of Gondwana during the Guadalupian but also demonstrates that arid conditions were not uniformly severe, allowing the persistence of forested humid latitudinal belts or small biodiversity hotspots, that served as sanctuaries for plant biodiversity of Gondwana in the lead-up to the Guadalupian extinction.