Recovery from the most profound mass extinction of all time

摘要

The end-Permian mass extinction, 251 million years (Myr) ago, was the most devastating ecological eventof all time, and it was exacerbated by two earlier events at the beginning and end of the Guadalupian, 270and 260 Myr ago. Ecosystems were destroyed worldwide, communities were restructured and organismswere left struggling to recover. Disaster taxa, such as Lystrosaurus, insinuated themselves into almost everycorner of the sparsely populated landscape in the earliest Triassic, and a quick taxonomic recoveryapparently occurred on a global scale. However, close study of ecosystem evolution shows that trueecological recovery was slower. After the end-Guadalupian event, faunas began rebuilding complex trophicstructures and refilling guilds, but were hit again by the end-Permian event. Taxonomic diversity at thealpha (community) level did not recover to pre-extinction levels; it reached only a low plateau after eachpulse and continued low into the Late Triassic. Our data showed that though there was an initial rise incosmopolitanism after the extinction pulses, large drops subsequently occurred and, counter-intuitively, asurprisingly low level of cosmopolitanism was sustained through the Early and Middle Triassic.