UV radiation pulse played a role in a mass extinction event, fossilized pollen reveals

Ozone Layer Collapse Contributed to End-Permian Mass Extinction

Research has uncovered that pollen preserved in 250 million year old rocks contain compounds that function like sunscreen, these are produced by plants to protect them from harmful ultraviolet radiation (UV_B). The findings suggests that UV-B played a part in the end Permian mass extinction event

New discovery of sunscreen-like chemicals in fossil plants reveals UV radiation played a part in mass extinction events