The secrets behind T. rex’s bone crushing bites: Researchers find T. rex could crush 8,000 pounds
The giant Tyrannosaurus rex pulverized bones by biting down with forces equaling the weight of three small cars while simultaneously generating world record tooth pressures, according to a new study by a Florida State University-Oklahoma State University research team.
In a study published today in Scientific Reports, Florida State University Professor of Biological Science Gregory Erickson and Paul Gignac, assistant professor of Anatomy and Vertebrate Paleontology at Oklahoma State University Center for Health Sciences, explain how T. rex could pulverize bones – a capacity known as extreme osteophagy that is typically seen in living carnivorous mammals such as wolves and hyenas, but not reptiles whose teeth do not allow for chewing up bones.
Erickson and Gignac found that this prehistoric reptile could chow down with nearly 8,000 pounds of force, which is more than two times greater than the bite force of the largest living crocodiles – today’s bite force champions. At the same time, their long, conical teeth generated an astounding 431,000 pounds per square inch of bone-failing tooth pressures.
This allowed T. rex to drive open cracks in bone during repetitive, mammal-like biting and produce high-pressure fracture arcades, leading to a catastrophic explosion of some bones.
“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,” Gignac said.
The researchers built on their extensive experience testing and modeling how the musculature of living crocodilians, which are close relatives of dinosaurs, contribute to bite forces. They then compared the results with birds, which are modern-day dinosaurs, and generated a model for T. rex.
From their work on crocodilians, they realized that high bite forces were only part of the story. To understand how the giant dinosaur consumed bone, Erickson and Gignac also needed to understand how those forces were transmitted through the teeth, a measurement they call tooth pressure.
“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. “It is like assuming a 600 horsepower engine guarantees speed. In a Ferrari, sure, but not for a dump truck.”
In current day, well-known bone crunchers like spotted hyenas and gray wolves have occluding teeth that are used to finely fragment long bones for access to the marrow inside – a hallmark feature of mammalian osteophagy. Tyrannosaurus rex appears to be unique among reptiles for achieving this mammal-like ability but without specialized, occluding dentition.
The new study is one of several by the authors and their colleagues that now show how sophisticated feeding abilities, most like those of modern mammals and their immediate ancestors, actually first appeared in reptiles during the Age of the Dinosaurs.
i love that brenna must have a nervous and/or comfort habit of pulling her leo away by the front around her belly button to readjust. in nearly every meet since the beginning of time, at some point, bren gets a nice white chalk line right where her belly button is. it’s almost always there and it almost never goes away. heh. :’’)
oh brenna. one of the many goofy things i adore about you. :’D
Hey y’all! Your friendly neighborhood content aggregator just graduated from the University of Oklahoma with a Bachelor’s Degree in Communication! I’m now celebrating in California, so I’m going to be somewhat inactive until Wednesday evening.
Just keep on being the magical folks that you are, and congrats to all my fellow new college grads!
“To those who have misused their free speech in such a reprehensible way, I have a message for you. You are disgraceful. You have violated all that we stand for. You should not have the privilege of calling yourselves ‘Sooners.’ Real Sooners believe in equal opportunity. Real Sooners treat all people with respect. Real Sooners love each other and take care of each other like family members.” - Oklahoma University president David Boren
I was in class, and I had a package of Poptarts, but I was making a lot of noise trying to open the wrapper. I looked around to see if anyone noticed and I made direct eye contact with a guy so I stopped.
After class, the guy that I made eye contact comes to me and says, “I saw you with those Poptarts and i just want you to know that next time, open that bitch with no shame, there is never any shame in Poptarts”
That was the greatest advice I have ever received.
This was a reply to someone in this big topic about the Maya collapse. Sometimes people think that horses made the Spanish some kind of organic tank impervious to Native warfare. I wanted to inform that in many cases Natives were able to adapt, change, and continue to fight the Spanish despite the advantage a horse may have given them.
Cavalry, though, that was a game-changer in the Americas.
Not always. Remember, the Spanish did not conquer Mesoamerica by themselves. They had Native allies to do most of the fighting for them. According to Hassig (1988), cavalry only gave a slight advantage. On page 237 he writes,
It is true that cannons, guns, crossbows, steel blades, horses, and war dogs were advances on the Aztecs’ weaponry. But the advantage these gave a few hundred Spanish soldiers was not overwhelming. In any case, individual Aztec warriors were shown to be the equal of any Spanish soldier, and the Aztecs in general proved remarkably adaptable. Individual warriors are reported as having grabbed the horseman’s lances and thereby neutralized them. One conquistador recorded a case in which a warrior successfully defended himself against three or four Spanish horsemen. When they could not bring him down, one of the Spaniards threw his lance at the Indian, who caught it and fought for another hour before being shot by two archers and then stabbed.
And then Hassig continues on page 238 and 241,
Another factor favoring the Spaniards was their use of cavalry and mounted lancers. Before the Conquest, as noted earlier, the Aztecs used an open formation in their battle stance, since the denser closed formation is basically a tactic used to repel massed mounted attacks and was thus unknown to them. But open formations were ineffectual against cavalry charges. Nevertheless, the Aztecs quickly adopted strategies aimed at minimizing the effectiveness of the horse, but a major shift in tactics would have required considerable time, since it would involved retraining professional warriors. Closed formations were not adopted, apparently because while they might have cured the problem of a massed cavalry attack, they would have created a better target for Spanish gunners. Consequently, organizational changes played only a minor role in the Aztecs’ adaptation to the Spanish challenge; ineffective tactics were abandoned, but new ones were not adopted. Instead, the response was largely technological. Devices and practices were adopted that aimed directly at these novel threats.
“By the end of the Seven Years War British infantry regiments had cemented their long-standing reputation for being among the most formidable practitioners of fire tactics in Europe. Yet against the shaky American rebels, Crown commanders instead relied overwhelmingly upon shock tactics to deliver quick and cheap tactical decisions. This meant that British musketry was most commonly delivered in combat in America in the form of general volleys, which the troops threw in immediately prior to the bayonet charge.”
- Matthew H. Spring, With Zeal and with
(Norman, OK: University of Oklahoma Press, 2011), p. 214 - 215.
AJ Jackson (born October 26th) is a former level 10 gymnast who is currently a junior at the University of Oklahoma, majoring in health and exercise science. She did her club training at Eagles Gymnastics under Kim Fuchs.
2012 JO National Team Member
3-time JO Level 10 National Vault Champion
Earned 18 Missouri state titles over the course of her JO career
Collegiate Achievements (to date):
2016 Big 12 Co-Vault Champion
First team All-American on vault (2015) and floor (2016)
In 2006, Michaela Hutchison won the 103-pound title at the Alaskan state wrestling championships. She became the first girl to win a state high school championship against boys. Hutchison would go on to compete at Oklahoma City University, where she was a four time All-American and three time National Champion. Hutchison inspired countless Alaskan girls to pick up the sport, and in 2014, there were enough girls competing to warrant their own state tournament.