Image: T. rex computer model
Karl Bates / Peter Falkingham
Researchers used computer modeling to calculate the force of a tyrannosaur's bite, and found it was comparable to having an elephant sit on the victim.
updated 2/29/2012 12:01:55 AM ET 2012-02-29T05:01:55

Tyrannosaurus rex had the most powerful bite of any terrestrial animal — modern or prehistoric.

The force of T. rex's bite was comparable to having an elephant sit on the victim with each crunch, according to a paper in the latest issue of Biology Letters. The carnivorous dinosaur’s biting force was between 35,000 to 57,000 newtons at a single tooth.

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In comparison, human biting force is usually documented as being less than 1,000 newtons, suggesting that T. rex could have bitten through thick bone and probably whatever else it wanted to attack.

“I have no idea what the bite would do to an animal beyond hurt a lot,” co-author Karl Bates told Discovery News. “The force is obviously much higher than alligators and lions (some of the most forceful living animals), and you wouldn’t want to be bitten by either of those.”

Bates, a researcher in the University of Liverpool’s Department of Musculoskeletal Biology, and colleague Peter Falkingham of the University of Manchester artificially scaled up the skulls of a human, an alligator, a juvenile T. rex and an Allosaurus to the size of an adult T. rex. In each case, the bite forces increases as expected, but they did not increase to the level of the adult T. rex, suggesting that this formidable predator had the most powerful bite of any land animal.

Perhaps the only contender would be Gigantosaurus, another huge carnivorous dinosaur, but its bite force hasn't been measured yet.

Alligators hold the record for highest bite force of a living terrestrial animal, but Falkingham said he’s not sure how they would compare to great white sharks. Larger crocodilians, such as Nile crocs, have not been measured, but they would still not exceed the biting force of T. rex.

Previous studies estimated that T. rex bit at a force between 8,000 and 13,400 newtons, but this latest study tested a range of muscle powers, as it is not precisely known what the muscles of dinosaurs were like, since this tissue has not survived. The researchers believe their new numbers better match the size and body structure of T. rex a dinosaur thought to weigh more than 13,228 pounds.

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“We speculate in our paper that the high bite force of adult T. rex may be indicative of it being a ‘large prey specialist,’” Falkingham told Discovery News. He and Bates explained that the carnivore preyed upon various plant-eating dinosaurs, as evidenced by T. rex tooth marks found on bones for some of these large beasts.

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The scientists further determined that juvenile T. rex had a relatively weaker bite than the adult T. rex, even when size differences and uncertainties about muscle size were taken into account. This indicates the species underwent a change of feeding behavior as it grew.

“It certainly makes sense from a ‘survival of the fittest’ point of view for members of the same species to avoid competition with themselves,” Bates said.

John Hutchinson, a professor of evolutionary biomechanics at the University of London’s Royal Veterinary College, told Discovery News “there’s no question that T. rex had a remarkably strong bite — that’s old news — but this study suggests it had an even stronger bite than previously thought.”

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Hutchinson said the study utilized “a very sophisticated computer analysis.” He also agrees that the ecology of Tyrannosaurus changed dramatically during the dinosaur’s growth, which involved going from just 13 pounds to over 13,000 in less than 20 years. He said, “Once again, we see the power of the fossil record, and computer tools, in revealing amazing animals that are so unlike creatures today.”

Stephen Brusatte, a Columbia University paleontologist who is also a researcher at the American Museum of Natural History, agrees with the new study’s conclusions as well.

“The finding that T. rex had a remarkably strong bite force, on the order of magnitude of tens of thousands of newtons, really drives home how powerful this iconic dinosaur would have been,” he commented.

Brusatte thinks the most important part of the study is the analysis on differences between the juvenile and adult T. rex.

“Juveniles were probably better suited for feeding on smaller prey," he said, "whereas adults were true killing machines adapted to use bone-crunching bites to feed on some of the largest dinosaurian prey species.”

© 2012 Discovery Channel

Explainer: The world's seven deadliest dinosaurs

  • Copyright 1985 Mark Hallett, "Awakening of Hunger"

    Yeah, it's cliche to say Tyrannosaurus rex was deadly. But the tyrant king was likely true to the billing. Its bone-crushing jaws could splinter prey like toothpicks, after all. And the beast was big, up to 40 feet long, 20 feet tall, and may have topped the scales at nearly 16,000 pounds.

    The king walked on two legs over a vast territory in western North America at the end of the Cretaceous, about 65 million years ago. Scientists wonder whether T. rex was more a lumbering scavenger or a quick and agile predator, but dead or alive, its meals were big, meaty and bloody.

    T. rex wasn't the only deadly dino, however. The globe was filled vicious killers. Click the arrows above to see more.

    — John Roach, contributor

  • Family diner

    Demetrios M. Vital

    Family meals for Majungasaurus crenatissimus were often bloody affairs of the grimmest sort: Kin were the main course. The evidence of its cannibalistic ways comes from telltale tooth marks on Majungasaurus bones that match up perfectly with the size and spacing of teeth in its jaws.

    The 20-foot-long dinosaur stalked the plains of Madagascar about 70 million years ago. At that time, the crime-scene investigators said, pickings were often slim. Their data indicate Majungasaurus fed on dried out "dino jerky" from its plant-eating compatriots as well as members of its own species. Cannibalism was likely just as common among dinosaurs as it is among living animals, but the evidence is rare.

  • Brow beater

    Todd Marshall

    Eocarcharia dinops' brow was swollen into a massive band of bone. The menacing head piece may have been used as a battering ram against rivals and to attract potential mates. Its blade-shape teeth were reserved for disabling live prey and severing their body parts.

    The 110-million-year-old beast and its snout-nosed, gut-and-carcass-scavenging relative Kryptops palaios were discovered in Africa's Sahara Desert. The approximately 7-foot-tall and 25-foot-long duo likely teamed up with a third carnivore and feasted on the long-necked plant-eater Nigersaurus.

  • Vicious rocker


    The toothy Masiakasaurus knopfleri likely speared prey with its forward projecting front teeth and then sliced and tore the captives into chewy chunks with its bladelike rears. This type of tooth arrangement is otherwise unknown in predatory dinosaurs.

    Scientists believe the German Shepherd sized beast feasted on fish, lizards, and other critters on the southern supercontinent Gondwana in the Late Cretaceous period, about 65 to 70 million years ago.

    The first part of this dinosaur's name means "vicious lizard" and the second part is derived from the Dire Straits singer and guitarist Mark Knopfler, whose music inspired the discoverers as they toiled on the African island nation of Madagascar.

  • Biggest carnivore?

    Prof. Rodolfo Coria / Ap

    At about 40 feet long and weighing an estimated 6 tons, Mapusaurus roseae was one of the biggest meat-eating dinosaurs to ever stalk the Earth. Bones of several individuals were discovered in one place, suggesting the giants may have hunted in packs that could have toppled perhaps the largest dinosaur that ever lived — a 100-foot-long plant eater called Argentinosaurus.

    Mapusaurus lived about 100 million years ago and was bigger than well known Tyrannosaurus rex and possibly larger than its older cousin, Gigantosaurus. Its teeth were narrow and blade like, made for slicing its prey. The bones were discovered in the Patagonia region of Argentina.

  • Going green


    Falcarius utahensis is the living image of a vicious meat eater trying to go vegetarian. Scientists aren't sure if the bird-like relative of Velociraptor had fully kicked its taste for flesh, but its meat-cutting teeth had shrunk to leaf-cutting size and its gut had expanded sufficiently to ferment plants.

    Falcarius walked on two legs and stood about 4.5 feet tall. Head to tail, it was about 13 feet long and wielded sharp, curved, four-inch long claws — perhaps to grab a bite when it fell off the wagon? The dinosaur lived during the Early Cretaceous, about 125 million years ago, in what is today Utah.

  • Plant ripper

    No plants were safe from Gryposaurus monumentensis, a big boned, duck-billed dinosaur that could have eaten any vegetation it stumbled across. Its massive skull packed more than 300 teeth for slicing up fibrous greens. Hundreds more replacement teeth rested in its jawbone for the call-up to action.

    The dinosaur lived in the Late Cretaceous, about 75 million years ago on the western side of a giant, shallow ocean that split North America at that time. The plant-munching beast may have reached 30 feet long as an adult and had a 3-foot-long head.


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