Reconstructing the jaw muscles and measuring the bite force of these animals shows surprising variation in eating styles among the first herbivorous dinosaurs. The skulls of early dinosaurs are helping scientists at the Natural History Museum and the University of Bristol understand how some of the earliest herbivores may have evolved different ways of eating plants. Much is already known about how different dinosaurs consumed their food, but relatively little is understood about how they evolved their preferred eating styles. Senior author and palaeontologist at the Museum, Professor Paul Barrett, confirmed: “If you want to understand how dinosaurs diversified into so many different types so effectively, it’s critical to learn how they evolved to feed on such a wide variety of vegetation in so many different ways. This diversity in feeding mechanisms set them up to dominate life on land for millions of years to come.” The team studied five dinosaur skulls from the plant-eating group Ornithischia; Heterodontosaurus, Lesothosaurus, Scelidosaurus, Hypsilophodon and Psittacosaurus, with many of the key specimens coming from the Museum’s own collections. These five species constitute the earliest representatives of what would become the major herbivore dinosaur groups. Later ornithischian dinosaurs, like Triceratops and Stegosaurus, show a wide range of adaptations to eating plants yet their early relatives have not been examined properly, until now.