UPDATE: A groundbreaking study published on January 3, 2026, by researchers from New York University reveals that the ancient fossil Sahelanthropus tchadensis, dating back seven million years, could walk upright, potentially rewriting the early narrative of human evolution. This urgent finding suggests that bipedalism may have originated much earlier than previously believed.
Scientists have uncovered compelling anatomical evidence indicating that Sahelanthropus, despite its ape-like features and small brain, was capable of bipedal movement. The revelation stems from a significant skeletal structure—the femoral tubercle—previously linked only to human ancestors. This structure is crucial for the iliofemoral ligament, the strongest ligament in the human body, essential for upright walking.
The study’s lead author, Scott Williams, an associate professor at New York University, emphasized the importance of this discovery, stating, “Sahelanthropus tchadensis was essentially a bipedal ape that possessed a chimpanzee-sized brain and likely spent a significant portion of its time in trees, foraging and seeking safety.” This suggests that our ancestors may have adapted to bipedalism much earlier than previously thought, challenging long-standing views on human origins.
The research team, comprising experts from New York University, University of Washington, Chaffey College, and University of Chicago, utilized advanced 3D imaging and other analytical techniques to analyze the fossil’s leg and hip structures. Their findings were published in the journal Science Advances.
The fossil was first discovered in the Djurab desert of Chad in the early 2000s, sparking debates about its locomotion capabilities. Initial studies focused mainly on the skull, leaving questions about its walking abilities unresolved. However, the recent analysis of additional bones, including the femur and ulnae, has reignited discussions about whether Sahelanthropus should be classified as a hominin.
The researchers identified three key features in Sahelanthropus that support its ability to walk upright, including femoral antetorsion and the gluteal complex, which had been suggested by earlier research. Additionally, the fossil’s limb proportions offer further clues, as the relatively long femur compared to its ulna deviates from the ape-like structure typically seen in non-bipedal species.
Williams concludes, “Our analysis of these fossils offers direct evidence that Sahelanthropus tchadensis could walk on two legs, demonstrating that bipedalism evolved early in our lineage and from an ancestor that looked most similar to today’s chimpanzees and bonobos.”
This vital discovery not only enhances our understanding of human evolution but also raises new questions about the development of bipedalism and its implications for our ancestors’ lifestyles. As the debate continues, researchers and enthusiasts alike are eager to see how this new evidence will reshape the narrative of human origins.
Stay tuned for more updates as this story develops—scientists are now poised to delve deeper into the implications of these findings on the evolutionary timeline.
