Species: Likely Homo erectus, our direct ancestor. The footprints found in Ileret, Kenya represent the oldest undisputed evidence of hominins walking upright in an efficient manner characteristic of modern humans. Our style of upright walking, which Homo erectus appears to have shared, is energy-efficient and adapted for long distances. It involves a long stride with a spring-like mechanism in the arch of the foot. These particular footprints demonstrate a well-developed arch and a long stride, culminating in a propulsive toe-off similar to us.

By this period, Homo erectus set a precedent for the locomotion seen in future hominin species, including Homo heidelbergensis, Neanderthals, Denisovans, and even the shorter Homo floresiensis.