Long-term origination rates are reset only at mass extinctions

Diversification during recovery intervals is rapid relative to background rates, but the impact of recovery dynamics on long-term evolutionary patterns is poorly understood. The age distributions for cohorts of marine bivalves show that intrinsic origination rates tend to remain constant, shifting only during intervals of high biotic turnover, particularly mass extinction events. Genera originating in high-turnover intervals have longer stratigraphic durations than genera arising at other intervals, and drive the magnitude of the shift following the Cretaceous-Paleogene (K-Pg) extinction. Species richness and geographic range promote survivorship and potentially control rates through ecospace utilization, and both richness and range have been observed to expand more rapidly in recovery versus background states. Post-Paleozoic origination rates, then, are directly tied to recovery dynamics following each mass extinction event.