Plateosaurus evolved in the Late Triassic period and lived through to the Early Jurassic period. It was the first of the giant dinosaur herbivores, growing to around 9 metres long and 3-4 metres high. It had a long tail, long hind limbs, and a small head at the end of a fairly long neck. It had leaf-shaped teeth, and a beak-like jaw. Plateosaurus belonged to a group known as the prosauropods and was a relative - though not an ancestor - of the gigantic sauropods of the Jurassic and Cretaceous. Until their appearance all herbivores had been squat, short-necked animals incapable of reaching high foliage. Plateosaurus and the other prosauropods were the first dinosaur group to feed exclusively on plant-matter. Although Plateosaurus walked on four legs, palaeontologists believe that it could rear up on its hind legs and use its powerful clawed hands to pull in succulent branches. It was the first animal to evolve the ability to feed on relatively high vegetation. Many fossils of these dinosaurs have been found throughout Europe and several species have been identified. The abundance of Plateosaurus fossils at some localities has prompted the suggestion that they lived in herds and even that they migrated to avoid seasonal droughts.