A recent biomechanical study has shown that Dunkleosteus terrelli could bring its jaws together with a remarkable force of 5,000 Newtons (1,100lbs-force). That more powerful than anything other than a few crocs and dinos.
T. rex, for example, could clamp down on its meal with a crushing force of 13,000 Newtons (3,000lbs-force); but a modern spotted hyena, by comparison, exerts a force of only 2,000 Newtons (500lbs-force) when it cracks bones in its mouth.
Dunkleosteus was one of the first jawed fish, was probably one of the earliest vertebrates with a penis, and grew up to 10m (30ft) in length (they even have fossil evidence of its colour pattern).
The scientists go on to say the arrangement of its 'teeth' could focus the bite into a small area - the fang tip - with the incredible pressure of nearly 150 million Pascals (22,000lbs per sq inch).
Of course, now the question is "What did a monster like this eat?" To which the answer is "Anything it wanted to"