The Devonian is also known as the Age of Fishes, since several major fish lineages evolved at this time. Sea levels were high and the global climate was warm. Sea surface temperatures in the tropics averaged 30 Celsius, much like the warmer parts of the Pacific today. Growth rings from corals living during the Devonian period have provided evidence that there were more than 365 days in the year back then - about 404 at the start of the period, falling to 396 by the end.
Began: 417 million years ago
Late Devonian mass extinction
354 million years ago
Once thought barren, the Devonian ended with plants and animals exploiting a new ecosystem: swamp.
Dr Ted Daeschler, Philadelphia Academy of Natural Sciences and Prof Keith Thompson, Oxford University Museum talk about the Devonian environment and the world's first swamps. Programme first transmitted in 2001.
Reconstruction of the Earth in the Devonian period, 417 million - 354 million years ago. Credit: Dr Ron Blakey, NAU Geology.
During this period the following events are thought to have contributed to the Late Devonian mass extinction.