BIOTIC IMPACTS OF TEMPERATURE BEFORE, DURING, AND AFTER THE END-PERMIAN EXTINCTION: A MULTI-METRIC AND MULTI-SCALE APPROACH TO MODELING EXTINCTION AND RECOVERY DYNAMICS

Extinction and delayed recovery during the end-Permian extinction and Early Triassic has been linked to environmental instability brought on by volcanic outgassing and greenhouse conditions, but the relative importance of the myriad of environmental stressors at this time on recovery dynamics is not well understood. The interplay of biotic and environmental factors in determining recovery tempo and mode is highly complex, and must be analyzed using a multi-metric and multi-scale approach in order to capture all the intricacies of end-Permian extinction and recovery dynamics. Here, we explore Permian-to-Triassic ecological complexity in marine benthic invertebrate communities using a global dataset, and compare multiple regression models to determine which set of abiotic factors best predicts extinction and recovery patterns. We additionally test the importance of temporal scale of analysis in interpretations of recovery dynamics and modeling results, by including analyses at the epoch, stage, and substage scales bracketing the interval of extinction and recovery. We find differences in mode of recovery between the ecological metrics analyzed, with some metrics exhibiting an Early Triassic recovery lag, while others recover continuously or immediately following the initial extinction event. These recovery patterns are not observable at all temporal scales, however, highlighting the importance of scale-of-analysis in influencing interpretations. The regression model with δ¹⁸O_apatite mean values as the response variable is most often found to be the best-fit model across all time scales analyzed, though proxies of rock record fidelity and paleontological sampling effort become more important in finer timescale analyses. These results suggest that global ocean temperatures best predict patterns of extinction and recovery across several ecological metrics, and that thermal episodes during the initial extinction event and subsequently in the Early Triassic recovery period significantly suppressed benthic marine community health.