A prehistoric 'Jaws' which 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
(1,100lbs force). 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 known animals.
US researchers Mark Westneat and Philip Anderson told
the Biology Journal of the Royal Society that higher bite forces
had only been reported for some large alligators and dinosaurs.
Tyrannosaurus 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 ten metres (thirty feet) in length. The scientists
said the way its teeth were organised in the jaw meant that it could
focus its bite into a small area - the fang tip - with the incredible
pressure of nearly 150 million Pascals (22,000lbs per square 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 mouth.
This heavily armoured fish was both fast during jaw
opening and quite powerful during jaw closing, according to Westneat,
curator of fish at the Field Museum in Chicago.
This was possibly due to the unique engineering
design of its skull and different muscles being 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 which dominated aquatic ecosystems during the
Devonian period, between 415 million to 360 million years ago.
Dunkleosteus was surrounded by possible prey
which all required a really high bite force, according to Anderson,
working out of the University of Chicago. There were free-swimming,
fast animals which 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. The
seas of the Devonian were as busy as those of today.