Tracings done around the elephant's feet, showing their relative sizes.

While working with Angus, Dr. Sereno and Jeff Ogradnik noticed that the sole of the forefoot was much larger than the sole of the hind foot. The difference was nearly 1.5 times - the same difference they measured for the weight of the limb supported. That means that each sole is designed to carry the same load per unit area.

Footprint size, therefore, is a good estimator for the amount of total body weight carried by a limb.

As with limb circumference, sauropod footprints show the opposite condition to elephants. The hind print is much larger than the foreprint, confirming that most of the body mass of a sauopod like Jobaria was in the rear, borne by the hind limbs.