Of all the species that have ever lived, more than 99% are now extinct. Most of them quietly disappeared during periods of “background extinction”, whereby a handful of species become extinct every ...

Paleontologists recognize five big mass extinctions in the fossil record. At the end of the Ordovician period, about 443 million years ago, an estimated 86 percent of all marine species disappeared.

For decades, scientists have conducted research centered around the five major mass extinctions that have shaped the world we live in. The extinctions date back more than 450 million years with the ...

Extinction, the permanent death of an entire species, is as old as life itself. But against the constant ebb and flow of individual organisms, there have been particularly notable disasters—mass ...