By Colin Barras

Phil Degginger/Carnegie Museum / Alamy

The second-most severe mass extinction in Earth’s history may have been triggered by global warming. The discovery means that, for the first time, all of the largest known extinctions can be linked to a rapid rise in the planet’s temperature.

“It completes the jigsaw puzzle in many ways,” says Andrew Kerr at Cardiff University, UK. Geologists recognise five points in time when huge numbers of species were wiped out, although recent research suggests at least one of these might have been too …