Laetoli

A comparison of three-dimensional scans of hominin footprints. Top) A footprint made by an experimental subject using a normal, "extended" gait. Middle) A footprint made by an experimental subject using a "bent-knee, bent-hip" gait. Bottom) A Laetoli footprints. From Raichlen et al., 2010. About 3.6 million years ago, at a spot now in Laetoli, Tanzania, a pair of hominins trudged through the ashfall dumped onto the landscape by a nearby volcano. We don't know for certain what they looked like (it is generally believed that they were Australopithecus afarensis from the presence of fossils…

In 1978, a paleoanthropological team including Mary Leakey, Richard Hay, and Tim White made a startling discovery at Laetoli, Tanzania; in a bed of volcanic ash that would later be dated to about 3.5 million years old were the footprints of ancient hominids. The preserved trackway, found to contain the footprints of three individuals of the same species walking in the same direction during a very short period of time (possibly walking together as a group), would become one of the most important and iconic of hominid fossils, the fact that hominids were walking upright 3.5 million years ago…