An event in geologic time where one of more species became extinct over a relatively short period of time, largely due to a catastrophic global event, a natural disaster, or an abrupt change in the environment, and based on studies of fossil records and macroscopic evidence.
Examples of extinction-level event are Permian extinction of marine species, and Cretaceous extinction of various species, including dinosaurs.
- extinction event
- mass event
- biotic crisis