SELECTIVE EXTINCTIONS OF MARINE ORGANISMS INDICATE THAT THE COMPLEX INTERPLAY OF MULTIPLE STRESSORS, ELICITED BY CLIMATE CHANGE, CAUSED THE END-PERMIAN EXTINCTIONS

The ecological selectivity of mass extinctions reveals critical information on organismic traits as key determinants of extinction and hence the causes of extinction. To understand which factors led to the mass extinction of life during an extreme global warming event, we quantified the ecological selectivity of marine invertebrate extinctions in the well-studied South China region during the end-Permian mass extinction. We used a machine learning technique (i.e., categorized gradient boosting) to identify which ecological attributes best explain the extinctions. We found that mineralogy, habitat depth, motility, and physiology were the best predictors of extinction. Logistic regressions of these ecological attributes also show that extinction risk was greater for genera that were limited to deep-water habitats, had a stationary mode of life, possessed a siliceous skeleton or, less critically, had calcitic skeletons. These selective losses directly link the extinction to the environmental effects of rapid injections of carbon dioxide into the ocean-atmosphere system, specifically expanded oxygen minimum zones, rapid warming, and ocean acidification.