CHICAGO -- It could bite a shark in two. It might have been the first king of the beasts. And it could teach scientists a lot about humans, because it is in the sister group of all jawed vertebrates.
Dunkleosteus terrelli lived 400 million years ago, grew up to 33 feet long and weighed up to four tons. Scientist have known for years that it was a dominant predator, but new embargoed research to be published in the Royal Society journal Biology Letters on November 29 reveals that the force of this predators bite was remarkably powerful: 1,100pounds. The bladed dentition focused the bite force into a small area, the fang tip, at an incredible force of 8,000pounds per square inch.
Even more surprising is the fact that this fish could also open its mouth very quicklyin just one fiftieth of a secondwhich created a strong suction force, pulling fast prey into its mouth. Usually a fish has either a powerful bite or a fast bite, but not both.
The most interesting part of this work for me was discovering that this heavily armored fish was both fast during jaw opening and quite powerful during jaw closing, said Mark Westneat, Curator of Fishes at The Field Museum and co-author of the paper. This is possible due to the unique engineering design of its skull and different muscles used for opening and closing. And it made this fish into one of the first true apex predators seen in the vertebrate fossil record. This formidable fish was a placoderms, a diverse group of armored fishes that dominated aquatic ecosystems during the Devonian, from 415 million to 360 million years ago. Dunkleosteus bladed jaws suggest that it was among the first vertebrates to use rapid mouth opening and a powerful bite to capture and fragment evasive prey prior to ingestion.
To determine the bite force, scientists used the fossilized skull of a Dunkleosteus terrelli to recreate the musculature of the ancient fish. This biomechanical model showed the jaws force and mo
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Contact: Greg Borzo
gborzo@fieldmuseum.org
312-665-7106
Field Museum
28-Nov-2006