Variation in the recovery of tetrapods after the Permian extinction opened the door for dinosaurs and mammals

One of the most studied localities for the extinction of land-dwelling vertebrates during the EPME is the Karoo Basin of South Africa. This geographic area has a continuous record across this massive extinction event and the recovery period. To compare the recovery of vertebrates from different localities, Peecook studied other fossil assemblages from Zambia and Tanzania. "One would expect that animal communities on Pangea would be similar, but intriguingly contemporaneous ecosystems in the wake of the end-Permian mass extinction are starkly different from one another," Peecook said.

The recovery of organisms after the EPME is extremely important to understand how resilient both marine and terrestrial life is on Earth. The patterns of mass extinction events and subsequent recoveries are among the most powerful contributions of paleontology to evolutionary theory. Mass extinctions are recognized as global events; however, studies of single localities or regions deepen our understanding of extinction and recovery by revealing heterogeneity in timing and process.

Peecock found the recovery of organisms in the Middle Triassic regions studied are very dissimilar. Carnivores and archosaurs are diverse and abundant in Zambia and Tanzania, but relatively uncommon or absent in South Africa. Ecological diversity levels of the Zambian and Tanzanian assemblages are equal to or exceed Permian ecological diversities, whereas those of the Karoo Basin are less. Peecook stated, " The fossil record is our best source of data on the effects of massive disturbances on natural ecosystems, and their subsequent recoveries. We can't perform