Science News looks at new research revisiting an old idea – that mass extinctions have something to do with reversals in Earth’s magnetic fields. The two phenomena are looking more and more like they line up in the fossil record:
During the past 2.5 million years, eight species of one-cell marine animals called Radiolaria became extinct. Six of these extinctions occurred simultaneously throughout their geographic range immediately following magnetic reversals.
…
Earth’s magnetic field protects the planet from cosmic and solar radiation, but that field can weaken during pole reversals.
SN’s look back also links to a 2016 study specifically of a mass extinction 550 million years ago linked to increases in solar radiation.