plural of extinction level event

The rapid dying off of a large percentage of all animal species in a comparatively short period of time 65.5 million years ago. This coincides with the end of the Cretaceous period, and may have been caused by an impact event.

After one has seen the consequences of a decision, it is easy to tell whether or not the decision was favorable, but it is also too late, since the consequences have already occurred.

A mass extinction between the Triassic and Jurassic periods 201.3 million years ago.