This is the conclusion reached by a team of international researchers, whose findings are published in the journal Science.
“Animals like T-Rex, the theropod dinosaurs, most likely had some kind of lips, like a soft tissue that covered the mouth” to protect the teeth, says one of the study’s authors, Thomas Cullen.
Until now it was assumed that these animals were more similar to “crocodiles, with exposed teeth when the mouth was closed and no lips,” explains this professor of paleobiology at Auburn University.
Their conclusions aren’t final, but Cullen and other researchers examined theropods from various museums and followed several lines of study.
They observed, for example, the erosion of the enamel on the teeth of dinosaurs and crocodiles, the living animals most similar to theropods.
“We did it because enamel, as dentists have told some people, has to stay healthy and hydrated to be healthy,” Cullen explained. “If it’s exposed to the air too long, it becomes brittle, more likely to crack or get sick.”
According to the paleobiologist, the enamel on the outside of the teeth of living crocodiles wears away faster than the inside because they do not have lips.
“When we look at the thickness of the enamel on the inside and outside of the teeth in large tyrannosaurs, they don’t show this configuration like a crocodile,” he said, but a “more animal-like pattern that has lips.” “The thickness of the enamel is the same on the outer and inner side.”
The researchers wanted to know if the T. rex’s teeth were so big that they didn’t fit in the dinosaur’s mouth, and compared them to several lizards that have lips.
Some of the lizards have teeth so enormous that “it seems almost incredible that these teeth could be completely covered by lips, and yet they are,” Cullen said.
“And we found that… this scaling relationship is almost identical in theropod dinosaurs,” he added.
Cullen acknowledges that the famous movie “Jurassic Park” conformed to what science knew when it was made, but since then it “has gone quite a bit off the rails” in attempts to accurately depict these dinosaurs.