Buff upper arms let Lucy climb trees
Arm, leg bone X-ray data provide clues to famous hominid’s mobility
ARM STRONG Relatively long, robustly built upper arms let Lucy, the famous 3.2-million-year-old hominid, spend a lot of time in trees, scientists say. Scans of Lucy’s fossils also suggest she walked less efficiently than people today do.
J. Kappelman/Univ. of Texas at Austin