"Having high bite force doesn't necessarily mean an animal can puncture hide or pulverize bone, tooth pressure is the biomechanically more relevant parameter", Erickson said.
The king of dinosaurs could bite down with a force of 7,800 pounds-force (34,522 newtons), a force equal to the weight of three small cars, the researchers found.
That's because the T. Rex had a bite force of about 8,000 pounds, or 3,600 kg, while its long conical teeth could generate bone-crushing pressure of 431,000 pounds per square inch (PSI), or almost 3 million kilopascals, according to the calculations of researchers from Florida State University and Oklahoma State University in the US.
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. Normally only mammals like grey wolves and hyenas can pulverize bone in that way, though they rely on elements of tooth structure instead of pure force.
While it might be tempting to give the T. rex's massive size sole credit for its devastating bite, Gignac said that the creature's teeth are the real stars of the show.
The process is slightly different for carnivorous dinosaurs, as they were characterized by having huge lateral teeth, sometimes over 6 inches long in the case of the T. rex.
As per the new study, carried out by a team of paleobiologists from the Florida State University, the T-rex dinosaur could deliver one of the most powerful and forceful bites that any of the land animal in history.
As T-Rex was also capable of consuming bone, it must have had additional strength in its nine-inch razor sharp teeth. But if we go back into prehistory to the end of the Cretaceous period, we find a predator that could bite down with more than double that amount of crushing force: Tyrannosaurus rex. According to Erickson, each tooth would exert a pressure of about 431,000 pounds per square inch. By comparison, a crocodile's bite force measures about 3,700 pounds, and a human's jaws can chomp with an impressive 200 pounds.
To show that T.rex's teeth had what it took, Erickson, along with paleontologist Paul Gignac, performed a comprehensive analysis of the animal's bite, combining measurements from T.rex skulls and teeth, high-resolution casts, and an anatomical model Gignac developed during grad school to predict bite forces in crocodilians based on their musculature. The dinosaur's jaws applied so much force in a bite that they would crush the prey to a pulp.
From this, they were able to generate a model for T-Rex's bite. Also, the animal had more than 30 teeth in the upper jaw alone. The behaviour has been observed in present-day hyenas and wolves.
This ability to perform extreme osteophagy might have given T-rex an advantage over other carnivorous dinosaurs that lived at the time, as they were able to exploit large dinosaur carcasses for sustenance more fully. "They carefully reconstructed many muscles and accounted for important aspects of muscle architecture and physiology".