Long before dinosaurs walked the land a massive armored fish called Dunkleosteus dominated ancient seas Its fossilized head plates and blade like jaws have led some to describe it as a "sea monster" o ...

Roughly 360 million years ago, a shallow sea covered what is now Cleveland, Ohio. In its depths lurked Dunkleosteus terrelli, a 14-foot armored fish armed not with teeth, but with sharpened bone ...