What if “Jurassic Park” and most toy companies that feature the fanged tyrannosaur Rex were wrong? These famous dinosaurs most likely had lips covering their teeth, according to a study published Thursday.
“Animals like T-Rex, theropod dinosaurs, most likely had some kind of lip, soft tissue covering their mouth to protect their teeth,” Thomas Cullen, one of the authors of this study, told AFP Science magazine.
“This is a departure from many previous hypotheses that said they looked more like crocodiles, with teeth visible with their mouths closed and no lips,” adds this university professor of paleobiology from Auburn, Alabama, in the southern United States .
If the question isn’t fully resolved, the researchers studied a group of theropod dinosaurs from multiple museums to arrive at this new conclusion.
For example, they compared the wear and tear on the enamel of dinosaurs and crocodiles, the living animals closest to these theropods.
Tooth enamel “needs to stay hydrated to stay healthy,” says Cullen. “If it’s exposed to air for too long, it becomes friable and more likely to crack or get sick.”
According to the paleobiologist, the enamel on the outer part of the teeth of living crocodiles wears away faster than the inner part because they don’t have lips.
“When we looked at the enamel thickness on the inside and outside of the teeth of large tyrannosaurs, they didn’t show that kind of configuration like a crocodile,” he continues.
“They present an animal-like model with lips,” says Thomas Cullen. “The thickness of their enamel is the same on the outside and inside.”
The researchers also wanted to know if the T-Rex’s teeth might have simply been too big for its mouth, and compared them to many modern lipped lizards.
“Some monitor lizards have absolutely huge teeth today,” Cullen said. “It seems almost unbelievable that these teeth could be completely covered by lips, and yet they are.”
“And we discovered that (…) this scale ratio is almost identical for theropod dinosaurs”.
What implications for the representation of these famous predators in popular culture?
While Thomas Cullen acknowledges that the Jurassic Park movies managed to “stick to what was known about dinosaurs at the time,” he says attempts to “faithfully” portray theropods have “since completely derailed.”