All dinosaur skeletons show that these creatures had a “fully improved stance.” In other words, dinosaur legs were held straight under their bodies at all times. This enabled dinosaurs to grow bigger, cover longer distances, and move faster, compared to their reptile relatives that had their legs spread out on either side of their body. The dinosaur stance also enabled some of the animals to become bipedal (walk on two legs). It also helped all dinosaurs with something called “locomotor stamina,” which is the ability to run and breathe at the same time.