How jaws influenced dinosaurs diets

London: Just how serious was the killer T rex dinosaur's bite? Researchers have now revealed that the feeding style and dietary preferences of dinosaurs were closely linked to how wide they could open their jaws. Using digital models and computer analyses, Dr Stephan Lautenschlager studied the muscle strain during jaw opening of three different theropod dinosaurs with different dietary habits.

Theropods were a diverse group of two-legged dinosaurs that included the largest carnivores ever to walk the Earth.

The research looked at T rex, a large sised meat-eating theropod with a massively built skull and up to 15 cm long teeth and two other predatory and meat-eating theropods. All muscles, including those used for closing and opening the jaw, can only stretch a certain amount before they tear.

The results found that the carnivorous Tyrannosaurus and Allosaurus were capable of a wide gape (up to 90 degrees) while the herbivorous Erlikosaurus was limited to a small gape (around 45 degrees).

Between the two carnivores, Tyrannosaurus could produce a sustained muscle (and, therefore, bite) force for a wide range of jaw angles, which would be necessary for biting through meat and skin and crushing bone.