Researchers from the University of Bristol have now revealed that the feeding style and dietary preferences of dinosaurs were closely linked to how wide they could open their jaws.
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‘Yet, up to now, no studies have actually focused on the relation between jaw musculature, feeding style and the maximal possible jaw gape. They used them only in cases when they had to capture a larger prey.
Overall, researchers concluded that the T. rex and Allosaurus were capable of opening their jaws up to 90 degrees, while Erlikosaurus dinosaurs could only open their jaws up to 45 degrees, according to the release.
The herbivore, E. andrewsi, however, kept in line with the typical traits of plant-eating animals, and displayed a small jaw gape.
Lead scientist Dr Stephan Lautenschlager, from the School of Earth Studies at the University of Bristol, said: ‘Theropod dinosaurs, such a Tyrannosaurus rex or Allosaurus, are often depicted with widely-opened jaws, presumably to emphasise their carnivorous nature.
It may not come as a huge surprise to anybody who has seen Jurassic Park, but scientists have discovered the Tyrannosaurus rex could open its mouth really wide.
The study examined three species, meat-eaters Allosaurus fragilis, Tyrannosaurus rex and herbivore Erlikosaurus andrewsi.
The T. rex boasted a large, massively built skull with dagger-like teeth.
– Erlikosaurus andrewsi: closely related to the two theropods above, but a plant-eating animal.
Researchers created detailed computer models to fully understand the relation between muscle strain and jaw gape.
Dr. Lautenschlager also said that, “All muscles, including those used for closing and opening the jaw”, can only handle a maximum stretch before it suffers tear. The dinosaur species in the study were also compared to their living relatives, crocodiles and birds, for which muscle strain and maximal jaw gape are known.
The computer models also tested the strain on muscles during various jaw movements.
Among dinosaurs, T. rex appears to have had the best-sustained bite force, which would have allowed the dino to rip through flesh and skin, and to crush bone.
Its maximum jaw gape angle was larger than Tyrannosaurus rex, an even bigger carnivore that roamed North America about 66 million years ago and was certainly no slouch in this capability. This limit describes how wide an open can open its mouth and jaws and up to what size it can feed on.
Citation: ‘Estimating cranial musculoskeletal constraints in theropod dinosaurs,’ Stephan Lautenschlager. Published 4 November 2015.DOI: 10.1098/rsos.150495.
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The study suggests that Hollywood depictions of Tyrannosaurus rex and other prehistoric predators with terrifying gaping jaws are probably right.
