Page "Impact event" Paragraph 47

In the past 540 million years there have been five generally-accepted, major mass extinctions that on average extinguished half of all species.

One of the largest mass extinction to have affected life on Earth was in the Permian-Triassic, which ended the Permian period 250 million years ago and killed off 90 % of all species ; life on Earth took 30 million years to recover.

The cause of the Permian-Triassic extinction is still matter of debate with the age and origin of proposed impact craters, i. e. the Bedout High structure, hypothesized to be associated with it are still controversial.

The last such mass extinction led to the demise of the dinosaurs and coincided with a large meteorite impact ; this is the Cretaceous – Paleogene extinction event ( also known as the K – T or K – Pg extinction event ); This occurred 65 million years ago.

There is no definitive evidence of impacts leading to the three other major mass extinctions.