The 3.18 million-year-old human ancestor Lucy may have frequently climbed trees and nested in them at night to avoid predators, a new study of the hominim's fossilised skeleton suggests.


Scientists from the Johns Hopkins University and the University of Texas at Austin in the US said that the scan shows that Lucy's upper limbs were heavily built, similar to champion tree-climbing chimpanzees, supporting the idea that she spent time climbing and used her arms to pull herself up. The fact that her foot was better adapted for upright walking than grasping may mean that climbing placed additional emphasis on Lucy's ability to pull up with her arms and resulted in more heavily built upper limb bones, researchers said.


Exactly how much time Lucy spent in the trees is difficult to determine, they said. A recent study suggested that Lucy died from a fall out of a tall tree. This new study adds to evidence that she may have nested in trees at night to avoid predators, they added.