T-Rex’s Tongue Was Anchored In Its Mouth And Could Not Move, Research Shows

Dean MouhtaropoulosGetty Images

With a new entry in the long-running Jurassic Park series set to release this week, it’s quite fitting that a new piece of dinosaur trivia has come to light, just in time to change our preconceived notions of how the prehistoric creatures roamed the Earth.

In a study published in PLOS One (via Gizmodo), scientists have discovered that most dinosaurs, including the ferocious T-Rex, were unable to move their tongues around freely. Instead, most of them would have had their tongues anchored to the bottom of their mouth, not entirely different from an alligator. Up until now, dinosaurs have been portrayed as having tongues that are able to be freely moved around.

Scientists and researchers from both the University of Texas at Austin and the Chinese Academy of Sciences came to this conclusion by comparing the bones of long extinct dinosaurs, alligators, and pterosaurs (winged lizards) to those of more modern birds and alligators. Specifically, they compared hyoid bones, which act as an anchor for the tongue in both humans and other animals. However, in birds, hyoid bones can be extended greatly.

In order to compare the bone and jaw structures of each animal, high-resolution photos and scans of hyoid muscles and bones were taken from over a dozen modern animals, including 13 different species of bird and three alligators. Most fossil specimens were sourced from northeastern China, and were scrutinized for preservation of the fragile bones around the tongue. The fossils were those of smaller, bird-like dinosaurs, as well as the Tyrannosaurus rex and the aforementioned pterosaur.

Muscle and bone scans
Muscular, fleshy, bone or cartilage elements of the tongue in extant archosaurs and outgroups - Credit: Li et. al, 2018Featured image credit: PHYS One(CC BY 4.0 )

When comparing the scans and images, researchers found that the hyoid bones of most dinosaurs were very similar to those found in alligators and crocodiles. These bones, which were short and simple in structure, indicate that the tongues in dinosaurs were anchored and therefore far less mobile than originally thought to be.

In a statement found on EurekAlert, co-author and Jackson School Professor Julia Clarke stated that the findings detailed in the study mean that reconstructions and depictions that show dinosaurs with outstretched tongues are misleading and incorrect.

“They’ve been reconstructed the wrong way for a long time. In most extinct dinosaurs their tongue bones are very short. And in crocodilians with similarly short hyoid bones, the tongue is totally fixed to the floor of the mouth.”

Zhizheng Li, an associate professor at the Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences and lead author of the paper, hopes that scientists can further research the changes that birds’ mouths and throats have undergone over time.