New study of 7-million-year-old fossils from Chad proves Sahelanthropus tchadensis walked upright while still climbing trees.

Learn how detailed 3D analysis uncovered evidence that upright walking emerged near the very start of the human lineage.

Humans have been walking on two legs for millions of years. All vertebrate species have a pelvis, but only humans use it for upright, two-legged walking.* The evolution of the human pelvis, and our ...