Animals like T. rex and velociraptors, theropod dinosaurs, most likely had some kind of lips, soft tissues that covered their mouths to protect their teeth, explains Agence France-Presse Thomas Cullen, one of the authors of this study published in the journal Science(New window). (in English)
This is a departure from many previous hypotheses that said they looked more like crocodiles, with teeth that were visible when their mouths were closed and no lips, adds this professor of paleobiology at Auburn University in ‘Alabama.
We’re talking about thin lips, similar to those of lizards or Komodo dragons, says one of the study’s co-authors, Derek Larson, researcher and manager of the Royal British Columbia Museum’s paleontological collection.
“As these results become more widespread in the scientific community and in the public sphere, I think our depictions of T. rex will change going forward. »
— A quote from Derek Larson, Royal BC Museum
If the question isn’t fully resolved, starting in 2014, researchers studied a group of theropods 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 Thomas Cullen. If left exposed to air for too long, it becomes friable and has a greater chance of cracking or contracting disease.
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 thickness of the enamel on the inside and outside of the teeth of large tyrannosaurs, they didn’t show that kind of crocodile-like configuration, he continues.
They depict a model approaching animals with lips, Thomas Cullen suggests. The thickness of their enamel is the same on the outside and inside.
Derek Larson says the color of dinosaur lips and skin is still being researched.
Photo: Mark P Witton
The researchers also wanted to know if T. rex’s teeth might have simply been too big for its mouth by comparing them to many living 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 that’s what we found out […] This scale ratio is nearly identical for theropod dinosaurs.
When perception changes
After studying the way dinosaurs lived and evolved, we began to focus more and more on their appearance. Other methods will no doubt be able to verify these already fairly solid results, says paleontologist François Therrien of Alberta’s Royal Tyrrell Museum.
For example, it was hard to imagine that some dinosaurs had feathers, and yet. The game has changed since the first discoveries of feathered dinosaurs in the 1990s, he says.
What are the implications for the depiction of T. rex and velociraptors in popular culture?
While Thomas Cullen acknowledges that the Jurassic Park films managed to stay true to what was known about dinosaurs at the time, he says attempts to faithfully depict theropods have since gone haywire.
With information from Agence France-Presse