Motor mouth: T. rex could bite with the force of three cars

Tyrannosaurus rex aka T. rex was one of the most frightening animals to have ever existed on the planet.

"It was this bone-crunching acumen that helped T. rex to more fully exploit the carcasses of large horned dinosaurs and duck-billed hadrosaurids whose bones, rich in mineral salts and marrow, were unavailable to smaller, less equipped carnivorous dinosaurs", explained Gignac, as reported by Forbes.

"Having high bite force does not necessarily mean an animal can puncture hide or pulverise bone, tooth pressure is the biomechanically more relevant parameter", said Gregory Erickson from Florida State University.

To figure out how the dinosaur managed to snap bones into fragments, Gignac and Erickson constructed a computer model of a T. rex jaw. The ability to pulverize bones is called extreme osteophagy.

Mammalian crunchers such as wolves or hyenas slice their way through bones with specialized molars like hacksaws. They have specialized teeth for this goal.

What's more, he says, teenage T. rexs put on an impressive five pounds of mass daily, so the animals certainly benefited from the ability to munch on the bones of prey. The scientists discovered its teeth could generate 431,000 pounds of pressure per square inch. For bone crushing, however, the dinosaur's conical teeth generated enough pressure to cause bones to explode. Besides its enormous size and force, the Tyrannosaurus rex was helped by a specific set of tooth characteristics. And while we now know its arms were disproportionately small, given its large body, the formidable power of its teeth is indisputable. Measuring about seven inches in length, their teeth were replaced every two years after being worn.

"I'm surprised at the high tooth pressures they found for T. rex, because we usually consider the teeth to be blunt rather than super sharp", Snively continued. They also looked at birds, which are "modern-day dinosaurs". Erickson thinks his numbers, while conservative, are more accurate, because they're based on scaling forces up from the muscles of crocodiles, a close living relative. The T. rex model was based on the CT scan of a well-preserved skull.

To begin, the researchers developed and tested a 3D anatomical model that predicted the bite forces of the American alligator (Alligator mississippiensis). While the Tyrannosaurus rex applies about 8000 pounds of pressure, the biggest living crocodiles have a bite force of only about 3700 pounds. T-Rex could crush 8,000 pounds with its bite. With that kind of force, a T. rex bite wouldn't just have snapped bones, it could also have created the "catastrophic explosion" of some bone structures. In reality, some studies suggested that the T. rex might have been more of a scavenger, feasting mostly on dead prey as it was easier to obtain. He says, over the years, there have been lots of attempts to estimate the bite force of T. rex, and different numbers have been thrown out there. The crown of the best biters will go to the largest extinct crocodiles that were 35-40 feet long.

PAUL GIGNAC: What we came up with were bite forces of around 8,000 pounds.