You’ve seen the picture: a terrible T Rex, baring his teeth, tongue stretching out of his mouth. But new research says there is a problem with the classic image. Dinosaurs couldn’t stick out their tongues.

What’s wrong with this image? Image via all dinosaurs.

Despite the pictures you have seen in movies, new research, published June 20, 2018, in the peer-reviewed journal PLOS EN, reveals that dinosaurs could not stick out their tongues like lizards. Instead, their tongues were probably rooted to the bottom of their mouths in a way similar to alligators.

Researchers from the University of Texas at Austin and the Chinese Academy of Sciences made the discovery by comparing the hyoid bones – the bones that support and sharpen the tongue – of modern birds and crocodiles with those of their extinct dinosaurs.

The results indicate that the hyoid bones of most dinosaurs were like alligators and crocodiles, ie – short, simple and connected to a tongue that was not very mobile. The study’s co-author Julia Clarke from the University of Texas said these findings mean that dramatic reconstructions that show dinosaurs with tongues extending out between their jaws are wrong. Clarke said in a statement:

They have been incorrectly reconstructed for a long time. In most extinct dinosaurs, their tongue bones are very short. And in crocodiles with similarly short hyoid bones, the tongue is completely fixed to the floor of the mouth.

Fossils discovered in northeastern China with the sensitive hyoid bones – the bones that support and sharpen the tongue – are still preserved. The blue and green arrows point to the hyoid device. Image via Li et al. 2018th

According to a statement from the University of Texas:

The researchers made their discovery by comparing the hyoid bones of extinct dinosaurs, pterosaurs, and alligators to the hyoid bones and muscles of modern birds and alligator specimens. Hyoid bones act as anchors to the tongue of most animals, but in birds, these bones can extend to the tip. Since extinct dinosaurs are related to crocodiles, pterosaurs and modern birds, comparing anatomy between these groups can help researchers understand the similarities and differences in tongue anatomy and how properties evolved over time and across different lines.

What’s wrong with this image? Dinosaurs in reconstructions often appear with tongues wildly waving – a feature that is inaccurate, according to new research. Image via Spenser Wright / University of Texas at Austin.

The research also suggests that there is a link to the origin of aviation and an increase in heavy diversity and mobility. Unlike the short hyoid bones of crocodiles, the researchers found that pterosaurs, bird-like dinosaurs, and live birds have a great diversity in hyoid bone shapes. They believe that the range of forms may be related to flight ability, or in the case of flightless birds like ostriches and emus, developed from an ancestor who can fly. The researchers suggest that taking to the sky could have led to new ways of feeding that could be linked to diversity and mobility in tongues.

Zhiheng Li, associate professor at the Key Laboratory of Vertebrate Evolution and Human Origins at the Chinese Academy of Sciences, is the study’s lead author. Li said:

Tongues are often overlooked. But they do offer key insights on extinct animal life.

Heavy and hyoid reconstructions from live taxa of birds and reptiles. Image via Li et al. 2018th

Summary: New research reveals that dinosaurs couldn’t stick out their tongues.

T-rex

Tyrannosaurus is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex (rex meaning “king” in Latin), often called T. rex or generally T-rex, is one of the most well represented by the major theropods. Tyrannosaurus lived throughout what is now western North America, on what was then an island continent known as Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations from the Maastrichtian age during the Upper Cretaceous period, 68 to 66 million years ago. It was the last known member of the tyrannosaurids, and among the last non-bird dinosaurs to exist before the Cretaceous-Paleogene event.