T. Rex May Have Had a Full Pair of Lips

Paleontologists are starting to come around to the notion that tyrannosaurid theropod dinosaurs likely looked very little like their pop culture counterparts. (Photo: By Hugh K Telleria/Shutterstock.com)

Tyrannosaurs rex, the largest of the carnivorous dinosaurs and the reigning star of the "Jurassic Park" franchise, may have been a tad bit less frightening to behold than earlier assumed.

Not only are paleontologists more certain than ever that the T. rex was covered in feathers, but they're also starting to come around to the idea that it likely had a full set of lips and gums to protect its teeth.

"The available evidence would suggest that none of these animals — none of the theropod dinosaurs — should have their teeth sticking out of their mouths," Robert Reisz, a professor and specialist in vertebrate paleontology at the University of Toronto, told CBC News. "They look more ferocious that way but that's probably not real."

The evidence for a T. rex with fully developed gums and lips comes from the enamel on its teeth. In a presentation May 20 at the Canadian Society of Vertebrate Paleontology's annual meeting in Ontario, Reisz explained how enamel, because of its low water content, needs quantities of saliva to stay hydrated. To that end, a land animal like T. rex would require the same gums and lips that most all modern reptiles have to keep its teeth from drying out and being damaged.

As he notes in a statement, Reisz says the only exception is the crocodile, which spends much of its time in the water and does not require lips for protection. "Their teeth are kept hydrated by an aquatic environment," he adds.

Much like the mouth of a Komodo dragon, T. rex may have kept its ferocious bite hidden behind scaly lips. Likewise, its signature teeth likely appeared much smaller due to a thick gum line.

Paleoartist Paul Conway was actually ahead of the curve with his 2013 illustration of a T. rex with lips and hidden teeth. "Dinosaur fossils have been catching up with paleoart — and that's quite nice, that the fossil evidence actually is lagging behind the art"” he told Inverse.

For years now, the artist has been illustrating dinosaurs based on how they likely looked, i.e., more bird-like, warm-blooded and athletic. "I think the reality of what we know about dinosaurs is that they looked a lot less monstrous, and possibly, somewhat fancier and sillier," he added.

Want another classic T. rex characteristic shattered? It likely also did not have a terrifying roar, but more of a guttural, reptilian growl. "All that roaring stuff — I don't buy any of it," Conway told Inverse. "Predators don't just roar at their prey before they bite them."