Plateosaurus was one of the best-known of the prosauropods. This is the family of large plant-eating dinosaurs with long necks and long tails. They were the great-grandparents of the sauropods. It was a very common dinosaur during the late Triassic period. Skeletons of Plateosaurus have been found in over 50 places in Europe, in the area that is now Germany, France and Switzerland. It was the first of the huge herbivores. This means that it only ate plants. It was about 27 feet long, which is about the size of a school bus. It weighed as much as 1,500 pounds.
Plateosaurus walked on four thick legs. Its hind legs were bigger than its front legs and carried the weight of the dinosaur. It could stand up on its back legs to reach food in high places or defend itself against hungry predators. It had a long neck and a very long tail. It had a small head with a long snout. Its hands were large, with five fingers, and had sharp claws. Plateosaurus was most likely able to grab and hold its food with its hands. On its thumb was a large claw that it used to defend itself against predators. It had sharp, leaf-shaped teeth that could tear tough leaves from plants. It probably ate larger plants like conifers and cycads. It also had cheeks. Cheek pouches were useful for holding plant mush while it chewed.
Plateosaurus may have swallowed pebbles to help mash up tough leaves and other plant food in its stomach. These stones are called “gizzard stones” or “gastroliths”. The food would go down to the dinosaur’s gizzard and the stones would help grind the plant matter into a soft mush. Then it would be sent to the stomach. Plateosaurus lived in large groups like cattle. They may have migrated - or moved - twice a year across the desert-like land in one big group to look for more food. To protect the herd against predators, the younger dinosaurs would walk at the center of a group while the stronger grown-up Plateosaurus walked along the edges.