Epoch: Late Devonian
Size: 8-10m long
Dunkleosteus was a huge armour plated placoderm fish from the late Devonian period. During this time period it is extremely unlikely that it had any predators because of it’s size and it’s heavy armouring around the head. The most interesting thing about dunkleosteus however is the adaptations concerning it’s mouth and jaw. Dunkleosteus is predicted to have a bite force of 8000 pounds per square inch, which is over 2 times the saltwater crocodile, which has the highest bite force alive today and putting it just under Tyrannosaurus Rex for greatest bite forces of all time. It wasn’t just the force of the bite which made it dangerous either, instead of teeth it had two long bony plates. This meant that it could crush bones and anything else it needed to (at this point in history a lot of fish had evolved amour). Along with this ability to eat almost anything came another digestive attribute. Because of the amour plated fish and tough diet, it was necessary to regurgitate the tough parts of the prey such as armour plates that couldn’t be digested normally. It’s also known that during times of hardship dunkleosteus was cannibalistic, eating smaller dunkleosteus.