There have been approximately five major mass extinction events in the history of life on Earth, the most severe ones witnessing the loss of a vast majority of species.
Approximately five mass extinction events occurred throughout the evolutionary history of animals. Among the most severe of these was the event approximately 250 million years ago, known as the Permian-Triassic extinction event, which resulted in the loss of a staggering 96% of all species. These mass extinctions have been identified in the fossil record and represent periods when over half of all extant species abruptly disappeared. The fossil record demonstrates that these extinction events were global catastrophes that brought about massive reductions in biodiversity. Recovery times for biodiversity after these five events have occasionally been as long as 30 million years, indicating the profound impact they had on life on Earth.