Paleofloristic evidence of climate change near and beyond the Permian–Triassic boundary

Three successive plant assemblages are studied from the latest Vyatkian (Changhsingian)–basal Vetlugian (terminal Changhsingian–Induan) of the Volga–Dvina river basins, European Russia, correlated with marine and non-marine transitional PTB intervals elsewhere. The rise of conifers, a decrease of leaf size in the persistent Late Permian morphotaxa, and preliminary data on stomatal index indicate cooling in the terminal Vyatkian followed by an increase of atmospheric CO2 levels. These findings are compared with climatic reconstructions based on other climate proxies. A spread of aquatic plants and dvinosaurs suggest a trans-boundary pluvial event. The end-Permian loss of biological diversity is ascribed to atmospheric and sea surface cooling at the peak of global regression shortly followed by the peak of basaltic volcanism and eutrophication of aquatic environments. The previously published data on the high-latitude records of Pleuromeia and the rise of deciduous Phoenicopsis biome east of the paleo-Urals are discussed as evidence of a greenhouse episode in the Olenekian and temperization of global climates in the Carnian.