Tyrannosaurus rex would have had lips, Toronto paleontologist says

One of the world's most famous predators, the fearsomeTyrannosaurus rex is typically shown baring dozens of sharp, jaggedteeth but a Toronto researcher says the carnivore likely had lipsto cover them.

Robert Reisz, a professor at the University of Toronto whospecializes in vertebrate paleontology, says that contrary to what'sshown in movies and even museums, T. rex and his fellow theropodswould not have teeth that stick out even when their mouths areclosed.

His research is set to be presented Friday at a conference of theCanadian Society of Vertebrate Paleontology conference, held at theuniversity's Mississauga campus. The two-day conference beginsThursday.

Reisz says only a few land animals, such as elephants and wildboars, have exposed teeth and these have no enamel.

Meanwhile, the only animal with bared teeth that have enamel isthe crocodile, which is aquatic.

Reisz says theropods, which include other well-known dinosaurssuch as velociraptors and Albertosaurus, were land animals whoseteeth had enamel, making it far more likely they had lips.

"The available evidence would suggest that none of these animalsnone of the theropod dinosaurs should have their teeth stickingout of their mouths. They look more ferocious that way but that'sprobably not real," he said.

Though more work needs to be done to reconstruct what the ancientcreatures would have looked like, "all the evidence right nowpoints to the likelihood that they actually had their teeth coveredby essentially scaly lips," he said.

In reconstructing what dinosaurs looked like, scientists rely onpreserved anatomy -- typically bones, but sometimes skin and feathers-- and comparisons with modern animals, said Caleb Brown, apaleontologist working at the Royal Tyrrell Museum in Drumheller,Alta.

"And then a lot of it is artistic licence," said Brown, who hasnot seen Reisz's research.

"You have to estimate somewhere. One of the big ones we don'tknow about is colour. We're getting some details about colour fromfeathered dinosaurs but when we just have skin preserved we don'tknow what colour they are."

Whether or not theropods had lips has yet to be determined, andthat debate plays out in popular culture as well as scientificcircles, he said.

"It's kind of an ongoing joke in that when you draw a dinosaur,particularly a theropod, one of the meat-eating dinosaurs, youalways portray it with the mouth open and with these teeth beingshown," he said.

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Part of that is because "it makes the animals look morefierce," he said.

But it's also because for some dinosaurs, the teeth are the partthat paleontologists know best, since more are available, and itseems counterintuitive to hide them in displays, he said.

If if turns out that theropods did have lips, there would bescientific implications for how they chewed and processed food,Brown said.

Still, "the biggest change that you would see would be in howthese are portrayed to the public in what we call paleo art, orartists' reconstructions of these animals,"which then tricklesdown to movies and museum exhibits, he said.

Reisz said the popular depiction in movies such as the "JurassicPark" franchise has annoyed him "for a very long time becausethere is no real biology behind it."

Aside from their lack of lips, theropods are shown in movieswithout feathers and "looking emaciated," which he said is alsoincorrect.

Though the issue has been a longtime frustration, Reisz said hebegan researching it a year ago and plans to turn his presentationinto a paper to be submitted for peer review.

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