The Devonian

417 to 354 Million Years Ago

The Rhynie Chert in Scotland is a Devonian age deposit containing fossils of both Zosterophyllophytes and Trimerophytes, the two major lines of vascular plants. This indicates that prior to the start of the Devonian, the first major radiations of the plants had already happened. The oldest known vascular plants in the Northern Hemisphere are Devonian.

The vegetation of the early Devonian consisted primarily of small plants, the tallest being only a meter tall. By the end of the Devonian, ferns, horsetails and seed plants had also appeared, producing the first trees and the first forests. Archaeopteris, shown below left, is one of these first trees.

Also during the Devonian, two major animal groups colonized the land. The first tetrapods, or land-living vertebrates, appeared during the Devonian, as did the first terrestrial arthropods, including wingless insects and the earliest arachnids. In the oceans, brachiopods flourished, like the beautifully pyritized brachiopod Paraspirifer bownockeri from Ohio, pictured above and to the right. Crinoids and other echinoderms, tabulate and rugose corals, and ammonites were also common. Many new kinds of fish appeared.

During the Devonian, there were three major continental masses: North America and Europe sat together near the equator, much of their current land underneath seas. To the north lay a portion of modern Siberia. A composite continent of South America, Africa, Antarctica, India, and Australia dominated the southern hemisphere.

Click on the buttons below to learn more about the Devonian.

Silurian Carboniferous
Subdivisions of the

The chart at left shows the major subdivisions of the Devonian Period. This image is mapped to take you back to the Silurian, or forward in time to the Carboniferous Period.

The Devonian Period is part of the Paleozoic Era.

One of the best places to learn more about the Devonian is the Devonian Times site.

Tour Devonian Fossil Gorge near Iowa City.

Visit Karl Wilson's site on New York Paleontology, which includes a nice section on New York in the Devonian.

Find out more about the Devonian paleontology and geology of North America at the Paleontology Portal.