With the help of a sophisticated engineering tool, researchers have unlocked the secrets of one dinosaur's bite. The new work, published today in the journal Nature, sheds light on the feeding behavior of Allosaurus, a Jurassic predator about which fairly little is known.
Paleontologist Emily Rayfield of the University of Cambridge and her colleagues employed a technique often used to test the strength of bridges--finite-element analysis (FEA)--to create a digital model of Allosaurus's skull. They then used the computer simulation to explore how the bone would have responded to stresses transmitted during feeding. Even though the carnivorous biped sported a mouthful of sabre-like teeth, the team found that the beast actually had a relatively weak bite--far weaker than that of its mighty cousin T. rex. The analysis revealed that although the dinosaur's skull would have been able to withstand considerable impact, its teeth would not have been able to survive heavy loading.
Rayfield and her colleagues suggest that the seemingly paradoxical combination of a strong skull and a weak bite is an adaptation to a certain feeding strategy similar to that seen in Komodo dragons. Whereas T. rex inflicted a fatal bite with its powerful, crushing jaws, Allosaurus may have lunged head-on into its prey, delivering a high-impact bite in a manner akin to a person wielding a hatchet, and then sliced flesh away on retracting.
"Allosaurus may have 'traded' a heavy skull and bite strength for greater speed and mobility of upper-jaw impact in order to capture lighter and more agile forms such as ornithopod dinosaurs," the team writes. "Allosaurus might have ambushed larger, more dangerous prey (for example, stegosaurs and sauropods) by inflicting a sudden devastating high-impact attack bite before the defender could retaliate."