Alligators: Champion Chompers

Sept. 15, 2003 — Cheetahs chomp hard and even humans can bite through an ear, but one animal reigns supreme when it comes to possessing the strongest bite — the alligator.

American alligators, Alligator mississippiensis, have the most powerful bite force ever measured. According to a recent study published in the Journal of Zoology of London, alligators snap their strong jaws shut with a force of 2,125 pounds, or with about as much force as a mid-size sedan falling on top of someone.

The 2,125-pound measured bite came from a 12 1/2 foot alligator weighing 665 pounds, appropriately named Hercules. Since completion of the study, that impressive record was broken.

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"Bite force is linked to the size of an animal," explained Kent Vliet, a University of Florida zoologist who headed up the study. "Since the report was published, we measured the bite of a wild gator, even bigger than Hercules at 13 1/2 feet in length missing the end of his tail. He bit down with a force of 2,960 pounds."

Measuring the champion chompers took Crocodile Hunter tactics, since the otherwise mellow alligators would not voluntarily attack the metal "bite bars" created by Vliet and his colleagues. Similar to tuning forks, the bars contained strain gauges that measured force.

Vliet had to lasso his subjects and secure them to a backboard. The process understandably annoyed the alligators, which caused them to bite down with defensive strength.

"We covered the bars with leather to prevent tooth damage, but in our videotapes you can see small chips and slivers of teeth flying off, which tells us the alligators were approaching their biting limits," Vliet told Discovery News.

To put the record measurement into perspective, hyenas, which are bone-crushing mammals, have a bite force of 1,000 pounds, slightly more than the 940 recorded for lions. Dusky sharks manage 330 pounds of force, and a common dog, the Labrador, bites with 125 pounds of force. Humans surprisingly beat out the pet dog, and measured in at 170 pounds of force.

It is still not a good idea to mess with a shark or lion.

"There is a lot more to biting and feeding ecology that brute jaw force," explained Vliet. "Lions, for example, have scissor-like teeth, while those of an alligator are blunt and pointed."

While it is unclear why alligators have such powerful jaws, Vliet said it could help them to incapacitate prey and munch on one of their favorite foods, turtles. When consuming turtles, gators eat both the shell and meat.

The study may also reveal information about dinosaurs.

"Crocodilians, such as the alligator, are the closest living relatives to dinosaurs," said Gregory Erickson, a professor of anatomy and vertebrate paleobiology at Florida State University in Tallahassee. "Their jaws, teeth and musculature provide an excellent model for the feeding biomechanics of these extinct beasts."

Erickson and Vliet indicated that small theropods, or bipedal carnivorous dinosaurs, bit down with no more than 450 pounds of force, but Tyrannosaurus rex may have been the world's most impressive biter with a force of around 3,300 pounds.