Core Viewpoint - A new study suggests that the Sahelanthropus tchadensis, an ancient hominin that lived approximately 7 million years ago in Africa, likely possessed the ability to walk upright, providing new evidence that it may be the oldest known human ancestor [1] Group 1 - The Sahelanthropus tchadensis fossils, which exhibit a mix of ape and human characteristics, were discovered in 2001 in a desert in Chad, with the initial find being a skull followed by several limb bones [1] - There has been long-standing debate in academia regarding whether Sahelanthropus tchadensis is a direct ancestor of humans or an extinct side branch of hominins, with a key point of contention being its ability to walk upright [1] Group 2 - Researchers from New York University and other institutions utilized 3D imaging and other technologies to analyze the limb bones of Sahelanthropus tchadensis, identifying three anatomical features that support the capability for upright walking [1] - The findings indicate that the ability to walk upright emerged early in primitive humans, suggesting that Sahelanthropus tchadensis may have resembled modern chimpanzees or bonobos and lived in wooded areas, capable of walking upright on the ground while still spending considerable time foraging and sheltering in trees [1]