Jackson School of Geosciences challenges perceptions about T. rex

Sarah Bloodworth

The Tyrannosaurus rex, whose name translates to king of the tyrant lizards, is the aggressive poster child of dinosaurs. The proclaimed king of the dinosaurs reigns over our books, museums and most recently, movies such as “Jurassic World 2” — where the T. rex is featured on a poster.

While T. rex were certainly voracious predators throughout the Late Cretaceous period, which took place 68 to 66 million years ago, new discoveries, including some from the Jackson School of Geosciences, might change our assumptions about the all-mighty T. rex.

Images of the T. rex often feature a wide-open mouth, revealing a gnarly tongue stretching out among some spine-chilling and spine-cracking teeth. However, UT researchers recently debunked the myth that the T. rex could even stick out its tongue. Instead, their tongues were likely rooted to the bottom of their mouth like crocodilians, according to the research.

Zhiheng Li, lead author of the study published in PLOS One in June, said the team discovered this by comparing U-shaped hyoid bones, which support the tongue, among a long ancestry of crocodilians, birds and dinosaurs.

“The short and delicate hyoid does not support prior popular conceptual reconstruction for the T. rex’s tongue that can stick out their mouth,” Li said. “I have concern about their super muscular and extended tongue reconstruction in the media. But without the mobile tongue, T. rex still can still be of ferocity.”

Li said the team’s data improves the understanding of the evolution of anatomical traits that lead to hyoid variation in living birds, which are related to dinosaurs. In fact, according to National Geographic, the discovery of protofeathers, or featherlike filaments on the T. rex cousin Dilong paradoxus, ruffled some feathers about whether the T. rex was a scaly beast at all.

UT geology professor Julia Clarke, who also studied hyoid bone structures, said while the T. rex may have not been fully covered in protofeathers, it had many birdlike characteristics.

“Based on the evidence to date, I think portions of the animal had skin and some scales, but other parts had bristlelike filaments that we think are feather precursors,” Clarke said. “There might be many birdlike aspects of T.rex including protofeathers in that lineage. … Tongue mobility is not one of them.”

The T. rex tongue may be crocodilian, but its body could have looked more like a chicken. And according to a paper published in the scientific journal Nature, a T. rex could only run a little faster than a chicken, if it all. Because the T. rex had thick legs and an imposing size, the study concluded that it is extremely unlikely the dinosaur could have reached speeds higher than 20 mph. Chickens can only run 9 mph.

T.rex aren’t even the largest predatory dinosaur to have lived. According to a 2016 Nature paper, the Spinosaurus, which lived at the same time as T.rex, took that title at an estimated 52 to 59 feet long and 7.7 to 9.9 tons — a little more than the weight of an African elephant.

Clarke’s 2016 research even found that the T. rex may have been closed-mouth vocalizers, meaning that it would have emitted sound through its neck rather than its mouth. This would result in a coo, like a pigeon, or even a quack. Clarke said the media’s representation of the T. rex, up to its wicked intentions, is film fantasy.

“(The media) is largely not particularly accurate in (portraying the T. rex’s) speed, when and how it makes noise, the evil glint in its eye — I think all of these are not accurate,” Clarke said.

Despite all the facts, T. rex are still regarded as one of the best dinosaurs to ever roam this planet and will no doubt continue to star in our media at varying degrees of accuracy.

Long live the king.