The Late Devonian Extinction refers to an event, or series of events, in which more than 20% of all of Earth's marine life was eliminated.

Many entire biological 'families' of species permanently disappeared from the fossil records.

There is disagreement about whether the extinctions were 'rapid' i.e. within about half a million years, or over a far longer period, about 25 million years.

Many different causes have been suggested, including :

• asteroid impacts
• supernova events
• volcanic eruptions
• ozone depletion
• the effects of plant evolution

See: Wikipedia

For an in-depth discussion of the extinction(s), hear BBC's 'In Our Time' podcast, March 2021.

Also see : Dinosaur extinctionplugin-autotooltip__plain plugin-autotooltip_bigDinosaur extinction

"The question why non-avian dinosaurs went extinct 66 million years ago (Ma) remains unresolved because of the coarseness of the fossil record. A sudden extinction caused by an asteroid is the most accepted hypothesis but it is debated whether dinosaurs were in decline or not before the impact.