Definition: The Devonian Period (408-360 Myr BP) is the fourth of six periods that make up the Paleozoic Era. It is preceeded by the Silurian Period and followed by the Carboniferous Period.
The Devonian Period is also referred to as the Age of Fishes, because it is during this period that fish such as agnanthans and placoderms attained their highest levels of diversity. Additionally, true bony fishes (Osteichthyes) and cartilaginous fishes (Chondricthyes) first appeared and both groups are thought to have evolved from the placoderms.
During the Devonian Period, life on land became abundant and diversified. Plants that emerged during this time period included club mosses, horstails, ferns, mosses, and liverworts. Towards the end of the Devonian, the first amphibians evolved. The earliest known fossil amphibian is Ichthyostega, known by a specimen that was unearthed in eastern Greenland.
