A 7-Million-Year-Old Skull Starts a Debate: Did Our Oldest Ancestor Walk Upright?

Did our earliest known ancestor already walk on two legs seven million years ago? The discovery of Sahelanthropus tchadensis, nicknamed "Toumaï," transformed our understanding of human origins, but scientists remain deeply divided over one crucial question. New analyses of the skull and limb bones are reigniting one of paleoanthropology's most fascinating debates: when did humanity truly stand up?