A prehistoric 'Jaws' that roamed the seas 400 million years ago
had the most powerful bite of any known fish.
The extinct creature, Dunkleosteus terrelli, could bring its
jaws together with a remarkable force of 5,000 Newtons
This performance surpasses all living fish, including today's
great white shark, and puts it up with some of the most powerful
bites in all animals.
US researchers Mark Westneat and Philip Anderson tell the
journal that higher bite forces have only been reported for some
large alligators and dinosaurs.
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.
The team developed its biomechanical model of Dunkleosteus by
studying the fossil remains of the fish, which probably grew up to
10m (30ft) in length.
The scientists say the way its teeth were organised in the jaw
meant it could focus its bite into a small area - the fang tip -
with the incredible pressure of nearly 150 million Pascals
(22,000lbs per sq inch).
Even more surprising is the fact that Dunkleosteus could also
open its mouth very quickly - in just one fiftieth of a second -
which created a strong suction force, pulling fast prey into its
"This heavily armoured fish was both fast during jaw opening and
quite powerful during jaw closing," said Westneat, who is curator of
fish at the Field Museum in Chicago.
"This is possible due to the unique engineering design of its
skull and different muscles used for opening and closing."
Usually, a fish has either a powerful bite or a fast bite, but
not both. The formidable fish was a placoderm, a diverse group of armoured
fish that dominated aquatic ecosystems during the Devonian Period,
from 415 million to 360 million years ago.
"Dunkleosteus was surrounded by possible prey that all required
really high bite force," said Anderson, who works out of the
University of Chicago.
"There were free-swimming, fast animals that all had a hard
armour; most of the other fish were other placoderms which had the
same hard bony covering. And then there were large molluscs with
hard shells and really large crustaceans," he said.