By | March 28, 2023

The popular cultural image of Tyrannosaurus rex may be wrong, according to new research.
AP Photo/Mary Altaffer, Archives

NEW YORK — The Tyrannosaurus rex often shown with massive, sharp teeth, like the wild creature in “Jurassic Park”.

But new research suggests that this classic image may be wrong.

The teeth of T. rex and other large theropods were probably covered by scaly lips, he concludes a study published Thursday in the journal Science.

The dinosaur’s teeth did not protrude when the mouth was closed, and even in a wide-open bite, you might only see the tips, the researchers found.

The research is the latest in a long back-and-forth over what dinosaur mouths really looked like.

New depictions show large teeth protruding from the dinosaurs’ jaws, even when they are closed. Some thought the predators’ teeth were simply too big to fit in their mouths, said study author Thomas Cullen, a paleontologist at Auburn University in Alabama.

However, when researchers compared the skulls of dinosaurs and living reptiles, they found that this was not the case.

Some large monitor lizards actually have larger teeth than T. rex compared to their skull size, and can still fit them under a set of scaly lips, Cullen said.

The researchers also found clues in the pattern of wear on tooth surfaces.

For a creature like a crocodile, whose teeth stick out of its mouth, the exposed part wears down quickly — “like someone has taken a grinder to the side of the tooth,” said another study author Mark Witton, a paleoartist at England’s University of Portsmouth. The study determined that T. rex likely did not have visible teeth like in “Jurassic Park.” ©Universal/courtesy Everett Collection

But when researchers analyzed a tooth from a Daspletosaurus, a relative of T. rex, they found that it was in good condition and did not show the uneven damage pattern.

With this evidence and other clues from dinosaur anatomy, the study makes a good case for lipped tyrannosaurs, said paleontologist Thomas Holtz of the University of Maryland, who was not involved in the study.

Still, “we’re not talking kissing lips,” he pointed out — they would be thin and scaly like those of the Komodo dragon, a large lizard.

It’s not the first time our depictions of dinosaurs have been called into question: Other research has shown that T. rex was more stooped than we used to think, and that fierce velociraptors probably had feathers.

Most of what we know about dinosaurs comes from their bones, but it can be harder to get clear answers about soft tissues like skin, which are not usually preserved as fossils. A new study concluded that T. rex probably had lips that covered its teeth. Mark P. Witton via AP An illustration of what T. rex’s mouth would have looked like. Mark P. Witton via AP

Adding lips can make dinosaurs look a little less violent, but it also makes them feel more realistic, Witton said.

“You don’t really see a monster,” he said. “You see an animal.”


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