The work could also lead to a rethinking of how some of the first land creatures stood and walked. Mammals tend to have legs and limbs that drop vertically from the pelvis to the ground, while those of reptiles tend to extend away from the body horizontally before turning back downward. The new reptiles had a "mammalian" arrangement for their limbs.
"We know from the trackways that these animals had their feet planted almost under their body," Berman said, "whereas in textbooks, they give them a sprawling gait as if the limbs are extended out from the body considerably. This just isn't true. You look at the trackway and you see that the footprints are very close to the midline of the body."