"Dinosaurs are considered to be reptiles. Unlike most reptiles dinosaurs all walked with their legs directly below their hips. This is different than a lizard or a crocodile where the top section of the limb is splayed out horizontally from the body and the lower section goes from the "knee" joint straight down to the ground. Because of this lizards and crocodiles move low to the ground and almost appear to be dragging themselves around on their bellies. In contrast, dinosaurs walked in an upright manner (Though a few species, likeTriceratops, did retain the lizard-like sprawl on it's front legs as it lumbered about)." ...more: