Dunkleosteus was a massive, prehistoric armored fish that lived about 358–382 million years ago during the late Devonian period. It belonged to a group of fish called placoderms, known for their bony armor plating around the head and thorax. Dunkleosteus could grow up to 30 feet long and had incredibly powerful jaws with blade-like bones instead of teeth. It was a top predator of its time, capable of biting through almost anything, including other armored creatures.