The hyoid bones of extinct species of the past were compared to the hyoid bones of present-day avian species and alligators.
They looked at hyoids in dinosaurs and in their closest living relatives, birds and crocodilians, to see if they could lick the problem of tongue-wagging capabilities in extinct dinosaurs. "But, they offer key insights into the lifestyles of extinct animals", said lead author Zhiheng Li, an associate professor at the Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences.He conducted the work while earning his Ph.D.at the UT Jackson School of Geosciences.
Portrayals of dinosaurs with lizard-like tongues hearken to early interpretations of the beasts as oversized lizards. This finding indicates that "the theatrical reconstructions of dinosaurs sticking their tongues out between their jaws are wrong", as reported the co-author of this research, Professor Julia Clarke.
Scientists revealed that many dinosaurs, such as the Tyrannosaurus rex, could not stick their tongues out.
Most of the dinosaurs the team studied had short and simple hyoids, similar to those of alligators and crocodiles.
The latest from researchers at the University of Texas, Austin, and the Chinese Academy of Sciences was also pretty similar but focused specifically on the mouths of ancient predators. The small arms of the T-Rex are so well-known that they often precede the dinosaurs' incredible reputation.
The researchers took high-resolution images of the hyoid muscles and bones from three alligators and 13 different species of bird and compared these to fossils of pterosaurs and Tyrannosaurus Rex.
The study was published on June 20 in the journal PLoS ONE. They think the range of shapes could be related to flight ability, or in the case of flightless birds such as ostriches and emus, evolved from an ancestor that could fly.
Beyond simply being a fascinating look at how dinosaurs compare to their modern counterparts (gators aside, at least), the researchers suspect it has something to do with flight.
So much for those dramatic depictions of dinosaurs, with their gaping mouths and huge waving tongues.
The researchers suggest that when dinosaurs traded their hands for wings, tongues became more important for manipulating their meals. They were particularly looking at the hyoid bones, which anchor the tongue to the body.
'Birds, in general, elaborate their tongue structure in remarkable ways. Hyoid similarities between dinosaurs and crocodilians suggest that their tongues resembled each others' as well, so dinosaurs were probably not capable of the tongue-stretching feats exhibited by birds, Clarke said. "That is one of the hypotheses that we put forward". Plant-eaters like Triceratops and the ankylosaurs, which had to chew their food, also had complex hyoid bones.
However, the researchers note that the fossil record as yet can't pin down when these changes to the windpipe occurred.