"Long before it's in the papers"
April 29, 2009

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Nature’s mightiest bites calculated

Aug. 4, 2008
Courtesy University of New South Wales
and World Science staff

The great white shark has the might­i­est bite of any liv­ing spe­cies known, a study has found—but its ex­tinct rel­a­tive “Big Tooth” may take the prize for hard­est bite in Earth’s his­to­ry.

The an­cient beast is thought to have in­flict­ed hor­ri­fic deaths on large whales, by first bit­ing off their tails and flip­pers and turn­ing the huge vic­tims into hap­less, drift­ing meals.

Extinct Mega­lodon would have been ter­ri­fy­ing even from the point of view of some­one on a mid-sized yacht, as this artist's por­tray­al sug­gests. (Im­age cour­te­sy Steve Al­ten/Mon­tage Mar­ket­ing)

The great white shark has the mightiest bite of any living species known, a study has found—but its extinct relative, “Big Tooth,” may take the prize for hardest bite in Earth’s history. The ancient predator is thought to have terrorized large whales by first biting off their tail and flippers. This left the huge victims immobilized and ripe for devouring. Researchers from the University of New South Wales in Australia and other institutions studied the skull and muscle tissues of both shark species. They generated 3-dimensional computer models of the skull of a 2.4-metre (eight-foot) male great white based on X-ray images. “Nature has endowed this carnivore with more than enough bite force to kill and eat large and potentially dangerous prey,” said the university’s Steve Wroe. “Pound for pound the great whites’ bite is not particularly impressive, but the sheer size of the animal means that in absolute terms it tops the scales. It must also be remembered that its extremely sharp serrated teeth require relatively little force to drive them through thick skin, fat and muscle.” Using imaging and analysis software and a technique known as finite element analysis, the team remodelled the skull, jaws and muscles as hundreds of thousands of tiny discrete, but connected parts. They then digitally “crash tested” the model to simulate different scenarios and determine the bite force, as well as the complex distributions of stresses and strains that these forces impose on the jaws. The findings are to appear in the Journal of Zoology. The group found that the largest great whites have a bite force of up to 1.8 tons—three times that of a large African lion and more than 20 times that of a human. Although shark jaws consist of elastic cartilage, as opposed to the bony jaws of most other fish, this didn’t greatly reduce the power of its bite, the researchers said. Wroe and colleagues applied the same method to estimate the bite force of “Big Tooth” or Carcharodon megalodon, which may have grown to 16 metres (52 feet) long and weighed up to 100 tons—at least 30 times as heavy as the largest living great whites. They predict it could generate between 10.8 to 18.2 tonnes of bite force. Even fearsome Tyrannosaurus rex was no match for this giant, Wroe said. “Estimates of maximum bite force for T. rex are around 3.1 tonnes, greater than for a living white shark, but puny compared to Big Tooth.”