It was a member of a group known as therapsids

It probably walked in a quadrupedal position

characterized by its large size and a distinctive feature: a tall sail on its back

narrow head

strong hind limbs

Dunkleosteus terrelli Protoceratops It was a member ofDunkleosteus terrelli was a species of arthrodirous placoderm fish that existed in the late Devonian period, from about 380 to 360 million years ago, in the Frasnian and Famenian. Contrary to previous estimates, recent research has shown that Dunkleosteus terrelli did not reach the enormous dimensions previously attributed. Instead of 10 meters in length, this armored fish is now believed to have been of a more moderate size, reaching approximately 3.