## Introduction The remains of the earliest human ancestor, Sahelanthropus tchadensis, have been discovered by a team of researchers. This groundbreaking discovery confirms that this primitive human ancestor walked on two legs. ## The Discovery A team of researchers conducted an in-depth study of the Sahelanthropus tchadensis remains. They used 3D geometric morphometrics to examine the fossils. ## The Result The analysis results show that the Sahelanthropus tchadensis had a femur with a femoral tubercle, a bony protrusion that is present only in some primitive human ancestors. This suggests that this ancient human ancestor walked on two legs. ## Implications The discovery of the Sahelanthropus tchadensis confirms that the earliest human ancestor was a primitive human who walked on two legs. This has significant implications for our understanding of human evolution. ## Conclusion In conclusion, the discovery of the Sahelanthropus tchadensis is a revolution in our understanding of the earliest human ancestor. This discovery confirms that this primitive human ancestor walked on two legs and has significant implications for human evolution. ## References For further information, please read the study published in Science Advances.