|Mounted skeleton of Plateosaurus, Eberhard-Karls-University Tübingen, Germany|
Plateosaurus (meaning 'flat lizard') is a genus of plateosaurid prosauropod dinosaurs. They lived during the Norian and Rhaetian stages of the Upper Triassic period, around 216 to 199 million years ago in what is now Europe.
The Plateosaurus was the first long-necked plant eater in the Triassic. An adult Plateosaurus could weigh up to 1,500 pounds (680 kg) and grow 27 feet (8.2 m) long. They used both hands to pull leaves off trees, but since they had weak teeth, they used their sharp thumb claws to defend themselves against predators.