It was 33 feet long, weighed four tons, had flesh-tearing bladed jaws that opened so quickly prey was sucked into its mouth, an 11,000-pound-force bite, and ate anything in the ocean that got in its way.

Scientists now say a prehistoric fish, Dunkleosteus terrelli, might have been "the first king of the beasts." The creature lived 400 million years ago and could tear a shark in two with one bite.

Research has revealed Dunkleosteus had the most powerful jaws of any fish ever, its bite rivaling that of T. rex and modern alligators.

"Dunkleosteus was able to devour anything in its environment," said study leader Philip Anderson, at the Department of Geophysical Sciences at the University of Chicago.

Scientists already knew Dunkleosteus was the dominant predator of its time.

Anderson and Mark Westneat, Curator of Fishes at the Field Museum in Chicago, used a fossil of Dunkleosteus to produce a computer model of its muscles and its bite. They found is could bite down with 11,000 pounds of force, which translates to 80,000 pounds per square inch at the tip of a fang.

And it was fast, opening its jaws in just one-fiftieth of a second. That action would have created suction to draw prey into its mouth.

Fish typically have a powerful bite or a fast bite, but not both, the researchers said.

Dunkleosteus was one of many species of placoderms, a diverse group of armored fishes that dominated aquatic ecosystems during the Devonian period, from 415 million to 360 million years ago. The creature's powerful bite would have allowed it to feed on other armored aquatic creatures of the time, including sharks and arthropods.

Had Dunkleosteus managed to survive, it would still be counted as a fearsome predator today.

"If one could stage a battle between a [20-foot] great white shark ... and a maximum-size Dunk, I would bet on the Dunk," Westneat told LiveScience.

The research is detailed in the Nov. 29 issue of the Royal Society journal Biology Letters.

Source:Xinhua/Agencies