A recent study, published in the Royal Society Publishing suggested that the feeding and dietary habits of dinosaurs were linked to the muscle strain capabilities of their jaw.

Three members of the theropods family of dinosaurs were studied in the investigation: Allosaurus fragilis a bipedal predator, Tyrannosaurus rex, a bipedal carnivore and Erlikosaurus andrewsi, a herbivore. Theropods were a diverse group of two-legged dinosaurs that included the largest carnivores ever to walk the Earth.

Researchers have taken a closer look at the jaws of a T. rex and have found that the feeding style and dietary preferences of dinosaurs was closely linked to how wide they could open their jaws. Credit: Stephan Lautenschlager/University of Bristol

Dr. Stephan Lautenschlager explained during a press release, “Theropod dinosaurs, such aTyrannosaurus rex or Allosaurus, are often depicted with widely-opened jaws, presumably to emphasize their carnivorous nature. Yet, up to now, no studies have actually focused on the relation between jaw musculature, feeding style, and the maximal possible jaw gape.”

The study

Dr. Lautenschlager and a group of investigators from Bristol’s School of Earth Sciences were able to determine the muscle strain of these dinosaur’s gape angle by using digital models and computer analysis. They simulated jaw opening and closing while measuring the length changes in the digital muscles. Researchers also compared their finding with data previously reported of the theropods living relatives such as crocodiles and birds.


The study suggested that the two carnivore dinosaurs were capable of a wide gape up to 90 degrees and the Erlikosaurus andrewsi had a wide gape of just 45 degrees. Investigators then related these finding to the feeding styles and dietary preferences of dinosaurs.

The two meat eaters had more muscle force in the range of jaw angles studied for biting through meat and skin and crushing bone. The Tyrannosaurus rex had a slightly stronger built than the Allosaurus fragilis, but both were strong enough to be predators.

This is why the author of the study, Dr. Lautenschlager, argued that the muscle used for opening and closing the jaw restricts the animal to what he can and cannot eat due to the muscle’s stretch limit.

Source: The Royal Society Publishing