“saurischian”

The Dinosaurs

The Dinosaurs Sunday, February 20, 2011 The Dinosaurs These animals were a large group of reptiles who were dominant land vertebrates for most of the Mesozoic era (245-65) million years ago. They appeared some 250 million years ago. They have an erect limb stance. This is very helpful to keep their bodies well above the ground. Dinosaurs are categorized in to two groups: saurischian (lizard-hipped) and ornithischians (bird-hipped).the dinosaurian were the most successful land vertebrates ever