Dunkleosteus

Dunkleosteus was a prehistoric fish belonging to the extinct placoderm group. Armor protected its head and the front of its body, while sharp jaw plates formed cutting surfaces. It lived in Devonian seas, much earlier than dinosaurs such as Tyrannosaurus. Preserved skulls and jaws provide important evidence, but the less completely known body means size and shape reconstructions require care rather than relying on older dramatic estimates.