A long-awaited, high-tech analysis of the upper body of famed fossil “Little Foot” opens a window to a pivotal period when human ancestors diverged from apes, new USC research shows.
Little Foot’s shoulder assembly proved key to interpreting an early branch of the human evolutionary tree. Scientists at the Keck School of Medicine of USC focused on its so-called pectoral girdle, which includes collarbones, shoulder blades and joints.
Although other parts of Little Foot, especially its legs, show humanlike traits for upright walking, the shoulder components are clearly apelike, supporting arms surprisingly well suited for suspending from branches or shimmying up and down trees rather than throwing a projectile or dangling astride the torso like humans.
The Little Foot fossil provides the best evidence yet of how human ancestors used their arms more than 3 million years ago, said…