The Devonian nekton revolution
The open water is supposedly colonised in force — though the evidence has since been challenged.
- When
- Known to
- ± 15 million years
- Era
- Devonian, Paleozoic
The Devonian was long argued to record a nekton revolution: a rapid occupation of the water column by actively swimming animals, as fish, ammonoids and other swimmers radiated away from the seafloor. A 2018 reanalysis of the global fossil database found swimming animals were already well established beforehand and did not diversify sharply during the Devonian at all. It is included here as a widely taught idea now under serious doubt.