It is all the imagination about the tyrannosaurus rex which is called into question by a study published Thursday in the journal Science. “Animals like T-Rex, the theropod dinosaurs, most likely had a kind of lips, soft tissue covering their mouths to protect their teeth,” Thomas Cullen, one of the study’s authors, told AFP.
“This is a change from many hypotheses so far, which were that they looked more like crocodiles, with teeth showing when their mouth was closed and without lips”, adds this professor in paleobiology at the university. from Auburn, Alabama, in the southern United States.
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The enamel of crocodiles and dinosaurs compared
If the question is not completely settled, the researchers studied a panel of theropod dinosaurs from several museums to arrive at this new conclusion. For example, they compared the wear of the enamel of the teeth of dinosaurs and crocodiles, the living animals closest to these theropods.
Tooth enamel “must stay hydrated to stay healthy,” explains Thomas Cullen. “If it’s exposed to the air for too long, it becomes crumbly and it’s more likely to crack or get sick.” According to the paleobiologist, the enamel on the outer part of the teeth of living crocodiles wears out faster than that on the inner part because they have no lips.
“When we looked at the enamel thickness on the inside and outside of the teeth of large tyrannosaurs, they didn’t show this type of configuration like a crocodile,” he continues. “They present a model closer to animals with lips”, indicates Thomas Cullen. “The thickness of their enamel is the same on the outer and inner sides.”
Representations of “Jurassic Park” fairly faithful to reality
The researchers also wanted to know if the T-Rex’s teeth could have been simply too big for their mouths, comparing them to many modern lizards with lips.
“Some monitor lizards today have absolutely huge teeth,” said Thomas Cullen. “It seems almost unbelievable that these teeth could be completely covered by lips and yet they are. And we found that (…) this scale ratio, is almost identical for theropod dinosaurs.
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What consequences for the representation of these famous predators in popular culture? If Thomas Cullen recognizes that the films Jurassic Park managed to “stick to what was known” about dinosaurs “at the time”, attempts to represent theropods “faithfully” have completely “derailed since”, according to him.