[Animals] The myth is over! The Tyrannosaurus rex had lips and they fulfilled an unexpected role

[Mockys.]

 

 

The question of whether or not dinosaurs had lips has been the subject of debate among hobbyists and some experts for years. Discussions have often centered on whether the addition of lips, like the fluffy body coverings, made dinosaurs less impressive and frightening to their fans than traditional toothed representations, and what evidence might justify such a change. AND

The new study finally offers some tangible evidence to settle the question, going beyond aesthetics to delve into the biology of extinct animals.

"There are many interpretations in paleoart. It's good to have scientific data to back it up," says Brink, a paleontologist at the University of Manitoba.

The proof of the discovery: the evolution of the dinosaurs
To determine whether dinosaurs like T. rex had exceptionally long teeth, Cullen (now at Auburn University), Brink, and their colleagues examined the anatomy of living lizards and crocodiles, the microscopic structure of dinosaur teeth, and compared the tooth size with skull dimensions in species ranging from T. rex to smaller carnivores such as Velociraptor and Coelophysis.

The star specimen, however, was the T. rex nicknamed Sue, the largest and most complete representative of the famous species (and exhibited at the Field Museum in Chicago). Although Sue appeared to have extra-long jaws, paleontologists found that her teeth had the same ratio to skull size as those of modern-day monitor lizards, and therefore did not require extraordinary lips to cover them.
 

A fundamental part of the research was to find modern analogues. Modern birds (descendants of dinosaurs) lack teeth, and crocodiles are evolved reptiles that live in water. However, while not as closely related, reptiles like monitor lizards are more useful because of their kinship with dinosaur anatomy.

(Discover more: They find a bird from the age of dinosaurs trapped in amber)

"This study is great paleontological forensic detective work," says University of Edinburgh paleontologist Steve Brusatte, who was not involved in the new research.

General analysis of it suggests that T. rex and other similar dinosaurs did not have very long teeth for their size: the lips could have easily covered their teeth. Most tellingly, dinosaur tooth enamel is relatively thin, and would have been prone to drying out if constantly exposed to air.

The lips would have kept their teeth moist and functional, something crocodiles don't have to worry about as aquatic animals.

"Cullen and his colleagues make an excellent case for the presence of extraoral tissues in non-avian theropods," says University of Pennsylvania paleontologist Ali Nabavizadeh, who was not involved in the new study.

Lips may not be unique to theropods. Recent studies of various herbivorous dinosaurs, such as long-necked sauropods and horned ceratopsians, have found evidence of gums, cheeks, and other soft tissue covering their teeth.

 

https://www.nationalgeographicla.com/ciencia/2023/03/se-termino-el-mito-el-tiranosaurio-rex-tenia-labios-y-cumplian-un-rol-impensado#:~:text=A pesar de que Sue,unos labios extraordinarios para cubrirlos