The Great Dying

A correspondent has brought THIS ARTICLE to my attention. The author looked at food webs over the Permian - Triassic period in North China. There were three extinction events over the period and their relative severity was measured.

The events were the Guadalupian-Lopingian extinction event (259.1 million years ago), the End-Permian mass extinction (251.9 million years ago) and the Triassic-Jurassic extinction event (201.3 million years ago). And the conclusion reached was that the End Permian was the most serious one. 

It took 10 million years for life to recover from that one, much less for the others. The difference was, as Mike Benton explains, 

"We found that the end-Permian event was exceptional in two ways, First, the collapse in diversity was much more severe, whereas in the other two mass extinctions there had been low-stability ecosystems before the final collapse. And second, it took a very long time for ecosystems to recover, maybe 10 million years or more, whereas recovery was rapid after the other two crises."

The article is based on a research paper in "Proceedings of the Royal Society B" reading of which gives one a measure of the amount of work which went into this research.

Very interesting stuff and I get to show a picture of a sabre-toothed gorgonopsian!

The plant-eating pareiasaurs were preyed on by sabre-toothed gorgonopsians. Both groups died out during the end-Permian mass extinction, or "The Great Dying." Credit: © Xiaochong Guo