A juvenile Edmontosaurus disappears into the massive, lipped mouth of Tyrannosaurus. Credit: Mark Witton
A recent research study challenges the depiction of predatory dinosaurs like Tyrannosaurus rex with exposed teeth, suggesting they had scaly, lizard-like lips rather. The findings suggest that lots of popular dinosaur depictions, including the renowned Jurassic Park T. rex, are incorrect.
A brand-new study recommends that predatory dinosaurs, such as Tyrannosaurus rex, did not have permanently exposed teeth as portrayed in movies such as Jurassic Park, however instead had scaly, lizard-like lips covering and sealing their mouths.
Artists and scientists have debated whether theropod dinosaurs, the group of two-legged dinosaurs that includes predators and leading predators like T. rex and Velociraptor, along with birds, had lipless mouths where constantly visible upper teeth hung over their lower jaws, comparable to the mouth of a crocodile.
A recent research study challenges the representation of predatory dinosaurs like Tyrannosaurus rex with exposed teeth, recommending they had scaly, lizard-like lips instead. The findings imply that many popular dinosaur depictions, consisting of the renowned Jurassic Park T. rex, are inaccurate. She included: “Dinosaur teeth have really thin enamel and mammal teeth have thick enamel (with some exceptions). Dr Witton said: “Some take the view that were unaware about the look of dinosaurs beyond basic features like the number of toes and fingers. Our study, and others like it, reveal that we have a significantly great deal with on numerous aspects of dinosaur look.
T. rex skull and head restorations. Credit: Mark Witton
However, an international team of researchers challenge some of the best-known depictions, and state these dinosaurs had lips similar to those of lizards and their relative, the tuatara– an unusual reptile found only in New Zealand, which are the last survivors of an order of reptiles that grew in the age of the dinosaurs.
In the most detailed study of this concern yet, the researchers took a look at the tooth structure, wear patterns and jaw morphology of lipped and lipless reptile groups and found that theropod mouth anatomy and functionality resembles that of lizards more than crocodiles. This indicates lizard-like oral tissues, consisting of scaly lips covering their teeth.
These lips were most likely not muscular, like they remain in mammals. A lot of reptile lips cover their teeth however can not be moved individually– they can not be curled back into a snarl, or make other sorts of motions we associate with lips in human beings or other mammals.
Research study co-author Derek Larson, Collections Manager and Researcher in Palaeontology at the Royal BC Museum in Canada, stated: “Palaeontologists frequently like to compare extinct animals to their closest living loved ones, however in the case of dinosaurs, their closest family members have been evolutionarily unique for hundreds of millions of years and today are incredibly specialised.
” Its quite exceptional how comparable theropod teeth are to monitor lizards. From the tiniest dwarf screen to the Komodo dragon, the teeth function in similar way. So, monitors can be compared rather positively with extinct animals like theropod dinosaurs based on this resemblance of function, even though they are not closely associated.”
Tyrannosaurus rex shouting with its mouth shut, like a vocalising alligator. With its mouth closed, all of the massive teeth of T. rex would be invisible behind its lips. Credit: Mark Witton
Co-author Dr Mark Witton from the University of Portsmouth said: “Dinosaur artists have actually gone back and forth on lips considering that we began restoring dinosaurs throughout the 19th century, however lipless dinosaurs became more popular in the 1980s and 1990s. They were then deeply rooted in pop culture through movies and documentaries– Jurassic Park and its follows up, Walking with Dinosaurs and so on.
” Curiously, there was never ever a dedicated research study or discovery instigating this modification and, to a large degree, it probably reflected choice for a brand-new, ferocious-looking aesthetic rather than a shift in clinical thinking. Were overthrowing this popular depiction by covering their teeth with lizard-like lips. This implies a great deal of our preferred dinosaur depictions are incorrect, including the renowned Jurassic Park T. rex.”
The outcomes, published in the journal Science, found that tooth wear in lipless animals was noticeably various from that seen in carnivorous dinosaurs and that dinosaur teeth were no larger, relative to skull size, than those of modern-day lizards, indicating they were not too huge to cover with lips.
A half-grown Tyrannosaurus, sporting a complete set of lips, diminishes Struthiomimus, a beaked ostrich dinosaur. Credit: Mark Witton
Also, the circulation of little holes around the jaws, which provide nerves and blood to the gums and tissues around the mouth, were more lizard-like in dinosaurs than crocodile-like. Designing mouth closure of lipless theropod jaws showed that the lower jaw either had to crush jaw-supporting bones or disarticulate the jaw joint to seal the mouth.
” As any dental practitioner will tell you, saliva is important for maintaining the health of your teeth. Teeth that are not covered by lips run the risk of drying and can be subject to more damage during feeding or battling, as we see in crocodiles, but not in dinosaurs,” stated co-author Kirstin Brink, Assistant Professor of Palaeontology at the University of Manitoba.
She added: “Dinosaur teeth have extremely thin enamel and mammal teeth have thick enamel (with some exceptions). Crocodile enamel is a bit thicker than dinosaur enamel, but not as thick as mammalian enamel. There are some mammal groups that do have actually exposed enamel, however their enamel is modified to endure direct exposure.”
A one-sheet summary of the main examinations and conclusions of the study. Credit: Mark Witton
Thomas Cullen, Assistant Professor of Paleobiology at Auburn University and research study lead author, stated: “Although its been argued in the past that the teeth of predatory dinosaurs might be too big to be covered by lips, our research study shows that, in reality, their teeth were not atypically big. Even the giant teeth of tyrannosaurs are proportionally comparable in size to those of living predatory lizards when compared for skull size, declining the idea that their teeth were too big to cover with lips.”
The results supply new insights into how we rebuild the soft tissues and look of dinosaurs and other extinct species. This can offer essential details on how they fed, how they kept their oral health, and the more comprehensive patterns of their development and ecology.
Dr Witton stated: “Some take the view that were unaware about the look of dinosaurs beyond basic features like the number of fingers and toes. Our study, and others like it, show that we have an increasingly good manage on lots of aspects of dinosaur appearance.
The researchers mention that their research study does not state that no extinct animals had actually exposed teeth– some, like sabre-toothed meat-eating mammals, or marine reptiles and flying reptiles with very long, interlocking teeth, probably did.
For more on this research study, see Deadly Teeth of T. rex Were Hidden Behind Scaly Lips.
Referral: “Theropod dinosaur facial reconstruction and the significance of soft tissues in paleobiology” by Thomas M. Cullen, Derek W. Larson, Mark P. Witton, Diane Scott, Tea Maho, Kirstin S. Brink, David C. Evans and Robert Reisz, 30 March 2023, Science.DOI: 10.1126/ science.abo7877.
