The Permian Period's Catastrophic End

The end-Permian mass extinction has been universally documented as the biggest extinction during the Phanerozoic and resulted in the extinction of 95% marine species and 75% terrestrial species. In the immediate aftermath the ecosystem was characterized by microbial and monotonous communities dominated by disaster taxa, and the whole recovery to the pre-extinction level took more than 5 million years. Although it is the most intensively-studied event, its causes and patterns remain contentious yet. To better constrain the timing, and ultimately the causes of this event, we collected a suite of geochronologic, isotopic and biostratigraphic data on tens of well-preserved Permian-Triassic sections in South China and the peri-Gondwanan region. High-precision U-Pb dating based on 29 volcanic ash layers and biodiversity pattern pooled occurrence data of 4500 species in a large geographic area reveal that the extinction interval happened in less than 200,000 years, and the extinction peak occurred at 252.28 million years ago and coincided with a d¹³C negative excursion of about 5‰. It was synchronous in marine and terrestrial realms. Oxygen- and calcium-isotope analyses in the extinction interval indicate a rapid warming and oceanic acidification in the sea. Associated charcoal-rich and soot-bearing layers and massive occurrences of breccia indicate widespread wildfires and catastrophic soil erosion on land.