Abstract

Mass extinction events are characterised by rapid and catastrophic decreases in biodiversity on a global scale. The investigation of these events is vital for understanding the resilience of ecosystems to extreme abiotic stresses, including climate change and environmental toxicity. Such studies may therefore help to predict the outcomes of analogous crises in the modern world. At the end of the Permian Period (251.9 Ma), the emplacement of the Siberian Traps large igneous province triggered a phase of rapid climatic warming and oceanic acidification. This culminated in the largest mass extinction in Earth’s history, with the loss of up to 95% of marine species over a 61 ± 48 ky timespan. However, the impact of the end-Permian extinction (EPE) on terrestrial ecosystems, particularly plant communities, remains poorly understood. Here we show that elevated concentrations of volcanogenic mercury across the Permian–Triassic boundary correlate with high abundances of aberrant spores and pollen grains. We interpret this to reflect severe environmental stress and mutagenesis in the parent plants, and propose that biomagnification of mercury may have been a significant yet unrecognised driver for the EPE .