Which physical characteristic is associated with quadrupedalism?

The physical characteristic associated with quadrupedalism is a long and narrow pelvis. This pelvic structure allows for the proper support and balance required for an animal whose locomotion relies on moving on all fours. Quadrupeds, such as many mammals, have evolved a pelvis that is elongated to facilitate the efficient movement of their limbs, providing stability during running, walking, or climbing.

In contrast, a short, bowl-like pelvis is typically found in bipedal organisms, as it supports an upright posture and is better suited for walking on two legs. An angled big toe is more indicative of adaptations for bipedalism, allowing for a stable push-off during walking and running, whereas a vertical posture relates directly to how an organism stands and moves on two legs rather than four. Quadrupedalism focuses on adaptations that enhance mobility on all fours, making the long and narrow pelvis essential for this form of locomotion.