The Dinosaurs

The dinosaurs were a large group of reptiles that were dominant large vertebrates (animals with backbones) for most of the meso era 245-65 million of years ago. There appeared some 230 million years and were distinguished from other scaly, egg laying reptiles by an important: dinosaurs had an erect limb stance. This enabled them to keep their body is well above the ground unlike the sprawling and semi sprawling stance of other reptiles. The head of the dinosaurs femur fitted into a socket in its pelvis producing effect and mobile locomotion. Dinosaurs are categorised into two groups according to the structure of their pelvis saurischian (lizard hipped) and ornithischains it’s slanted back, parallel to the ischium (another part of the pelvis). Dinosaurs raised in size from smaller than a domestic cat to the biggest land animal ever known. The Dinosauria world the most successful and vertebrates ever and survived for 165 million years until most common extinct 65 million years ago.