Devonian

The Devonian ( ) is a geologic period and system of the Paleozoic era during the Phanerozoic eon, spanning 60.7 million years from the end of the preceding Silurian period at million years ago (Ma), to the beginning of the succeeding Carboniferous period at Ma. It is the fourth period of both the Paleozoic and the Phanerozoic. It is named after Devon, South West England, where rocks from this period were first studied.

second series and epoch of the Devonian system and period

evolution of tetrapods to live on land