The Devonian period is known as the age of the fish, and for good reason. Fish fossils from this time are quite common. For the first time, fish were adapted to fresh water, as well as salt water. This was a major building block in the history of the earth and helped to establish food chains. Kinds of fish included: jawless fish, jawed fish (which made there debut in the Silurian period), early sharks, and bony fish. From Bony fish, early amphibians began to form.

Dunkeleosteus, a large armored fish.