Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff. Laurin Vogelbaum here. If you're like me, you've never really thought about whether or not Tyrannosaurus rex might have been a good kisser. Depictions of the so named tyrant lizard king a typically fixture a veritable phalanx of teeth protruding from its mouth even when its mouth is closed. It's an image made famous by the Jurassic Park movies. Think of that creepy crocodilian grin as it's hunting Doctor Grant, or
you if you've been on the theme park ride. But that image might not be accurate after all. A study published in March of twenty twenty three in the journal Science postulates that the t rex and its fellow therapod dinosaurs actually did have lips that covered their teeth, more
like modern lizards than crocodilians. A paleo Artists have often depicted therapod dinosaur mouths as similar to those of alligators and crocodiles, with enormous teeth protruding yet by comparing the ratio of tooth size to skull length with that of lizards like the komodo dragon. The researchers behind the study concluded that t rex teeth weren't necessarily too big to
be covered by dino lips. The authors bolstered their claim by comparing the teeth of a close relative to the t rex, the Displetosaurus, with those of an American alligator. While the enamel on the outer side of an alligator's teeth tends to wear down pretty quickly due to exposure to the elements, the enamel of the dinosaur's tooth evidenced no such pattern. This suggests the possibility that its teeth
were protected behind lips. The last piece of evidence the study relied on is the similarity between certain features of therapod dinosaur skulls and the skulls of lipped lizards like iguanas. A lipless crocodiles and alligators have small pores over their entire snouts that contain nerves sensitive to touch, heat, cold, and certain chemicals in their environments. Meanwhile, lizards like iguanas have a row of larger holes called foramina, aligned above
their teeth that contain nerves and blood vessels. A therapod dinosaur skulls are more similar to the lizards, suggesting that their facial structures were closer to that of lizards with lips, so case closed. As with everything dinosaur related, paleontologists draw their conclusions based on ancient and incomplete data, and other dinoscholars aren't so sure about this whole t Rex lips situation.
One Thomas Carr, a vertebrate paleontologist who has studied therapod facial structure, told Science that he didn't find the study persuasive. His own findings indicate that theropods snouts were tough, scaly, and devoid of soft tissue, and thus when it comes to lips more closely resembled crocodile snouts. It's also unclear whether exposure to the elements would have meaningfully damaged the teeth of t Rex. If the skeptics are correct, t
Rex might have been perpetually smiling for the camera. After all, a new evidence is always being investigated. This won't be the first time that paleontologists and paleo artists have revised their working draft of what the t rex's mouth looked like, and it probably won't be the last. In the nineteen twenties and thirties, for example, t Rex was often depicted with lips, and until we found a mummified fossil of
a t rex skull, we won't know for sure. We haven't even found any with skin patterning intact, so there's a possibility that t Rex had feathers like some of its smaller relatives. Today's episode is based on the article t Rex didn't Kiss and Tell, but may have had lips on how Stuffworks dot Com, written by Thomas Harlander. The brain Stuff is production of iHeartRadio in partnership with how Stuffworks dot Com and is produced by Tyler Klang.
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