Dinosaurs are a group of ancient reptiles that had a set of particular skeletal features.
The hips, hind legs, and ankles were specialized and allowed the legs to move directly under the body, rather than extending out from the side of the body as in modern lizards. This arrangement enabled dinosaurs to bring their knees and ankles directly below their hips and provided the necessary attachments for very strong leg muscles. The front legs were adapted for grasping prey, for supporting weight, or for walking and running. These skeletal features separated dinosaurs from other ancient reptiles such as Dimetrodon , the plesiosaurs, and pterosaurs. Maintained by Eastern Publications Group Web Team .