Dunkleosteus (pronounced dunk-lee-o-stee-uss) was the biggest predator in the Devonion sea. It was armour plated on the head, and instead of teeth it had giant plates of bone from its jaw that were just as dangerous, if not more so. The bone could cut through armour plating on other fish and slice through the inside of the fish with ease. The most unique thing about the "teeth" of Dunkleosteus is that they were like self sharpening scissors in the way that they would sharpen using each other! Dunkleosteus ate just about anything that crossed its path, including other Dunkleosteus. Dunkleosteus had very bad table manners, as well - it would crack open the plating of a fish like it was a nut and eat the fish inside, then later it would spit out the plates and bones that were left behind. Fossils show that when the Dunkleosteus died, they would rot away but the plates on its head and neck would remain preserved. They had NO known predators as it was so big and powerful. The average size of Dunkleosteus was about 33 feet long!