How wide can a dinosaur open its mouth? According to a new study, the Jurassic predator allosaurus could swing its jaws down at a terrifyingly wide right angle, opening its maw nearly 80 centimeters to bite massive prey, Reutersreports. The larger Tyrannosaurus rex could open its jaws at nearly the same angle, while a related plant-eating dinosaur had a much smaller gape of 43.5 degrees. The findings—published Tuesday in Royal Society Open Science—are consistent with measurements from modern animals, which show that carnivores tend to open their mouths wider than herbivores.