T-Rex Bite Force: Tyrant King Could Crush 8,000 Pounds and Make Bones Explode

Tyrannosaurus Rex exhibit at the Natural History Museum of Leiden, Netherlands. Dean Mouhtaropoulos/Getty Images

Tyrannosaurus Rex was one of the most fearsome dinosaurs that ever lived. And now scientists know why. Using advanced modeling techniques, they have found T-Rex could bite down with a force of 8,000 pounds. That's equivalent to the weight of three small cars, and twice as strong as the largest crocodiles alive today.

T-Rex, whose name translates to king of the tyrant lizards—or Tyrant King, roamed western America between 68 to 65 million years ago. It is believed to have been an apex predator, measuring up to 40ft in length and weighing up to 18 metric tons.

It is also thought to have had the largest bite forces of all terrestrial animals—but until now scientists did not know just how strong its huge jaws were. The study, by Gregory Erickson, professor of biological science at Florida State University, and Paul Gignac, assistant professor of anatomy and vertebrate paleontology at Oklahoma State University Center for Health Sciences, was published in Scientific Reports.

Erickson and Gignac used previous research in which they had looked at modern crocodiles—close relatives of dinosaurs—analyzing the arrangement of the muscles that contribute to their bite force. They then compared their findings with birds, which evolved from a group of dinosaurs called theropods, which T-Rex belonged to.

From this, they were able to generate a model for T-Rex's bite. Findings showed it could crush 8,000 pounds. "We didn't go in our study with any preconceived notions or expectations," Erickson tells Newsweek in an email interview. "Minimally, we expected forces over 6,800 pounds, since I had worked with Stanford engineers as a grad student replicating T-Rex bites on cow bones, and that value was deduced."

"The forces we found are prodigious, enough to sink the teeth several inches into bone and shatter them. That is all they needed to do. Natural selection tends not to grossly overbuild. It is not advantageous to waste resources that could be utilized elsewhere for growth, survival or reproduction."

Tyrannosaurus Rex exhibit at the Natural History Museum of Leiden, Netherlands. T-Rex could crush 8,000 pounds with its bite. Dean Mouhtaropoulos/Getty Images

As T-Rex was also capable of consuming bone, it must have had additional strength in its nine-inch razor sharp teeth. The scientists discovered its teeth could generate 431,000 pounds of pressure per square inch. This allowed it to munch on bones to the point where they would have exploded. And tooth pressure, the scientists say, is key.

"We have modeled bite forces for giant fossil crocs at 23,000 pounds, so Tyrant King was not the king in that regard," Erickson says. "Its tooth pressures, which are more important than bite forces with regard to feeding capacities are however the highest estimated (to date) for any animal."

This would have been highly advantageous to T-Rex. "It allowed them to utilize more of the carcasses of giant prey and scavenged individuals than competitors. Bones are composed of phosphatic salts and they house fatty marrow which T-Rex alone could captialize on," Erickson says.

Explaining what it would be like if a human got bitten by a T-Rex, he adds: "To quote Clubber Lang (Mr T) from Rocky III—'Pain'—albeit brief."