What are Mass Extinctions?

Mass extinctions are the polar opposite of background extinctions. They occur from an event and the extinction rate of species is rapid and spectacular. Such an extinction has been described by British paleontologists Anthony Hallam and Paul Wignall as a “significant proportion of the world’s biota in a geologically insignificant amount of time.” The losses are global, profound and at a rate that is fast relative to the framework of geological time.