Scientific American: News In Brief: Study Suggests Supernova Snuffed out Marine Life Two Million Years Ago: February 13, 2002

The phrase mass extinction often calls to mind such potential culprits as asteroid impacts and volcanism. But new research suggests that in the case of a die-off of marine creatures that occurred two million years ago, at the interface of the Pleistocene and Pliocene epochs, a different phenomenon was to blame. According to a report appearing in the February 25 issue of the journal Physical Review Letters, cosmic rays from the explosion of a nearby supernova may have done these animals in.