We now need to make further studies of the rocks with malformed spores to work out the duration of the extinction and the likely rate of temperature change required to push enough ozone-destroying chemicals high into the atmosphere.
The discovery of this potential new extinction mechanism indicates that a warming climate, such as we have now, has the potential to erode the ozone layer to let in damaging ultra-violet radiation.
Our research suggests the Earth has a natural internal process triggered by a warming climate that can destroy the ozone layer, a serious warning for our own period of climate change.
But we have shown that the extinctions on land at this time may have been caused by a catastrophic thinning of the ozone layer that let in damaging levels of ultra-violet radiation.
My colleagues and I have published new research on the mass extinction that took place 359 million years ago at the boundary between the Devonian and Carboniferous geological periods.