Final answer:
Sauropods used a quadrupedal stance for support and locomotion, walking on all four legs.
Step-by-step explanation:
Bipedal dinosaurs, such as sauropods, used a specific stance for support and locomotion. The stance they used is called 'quadrupedal stance', which means they walked on all four legs. In this stance, their forelimbs and hindlimbs were roughly equal in length, resulting in a stable and balanced posture. This stance allowed sauropods to support their massive bodies and move efficiently on land.