The famous human ancestor known as Lucy walked the Earth some 3 million years ago, but it was her tree climbing that might have led to her demise, a new study suggests. An analysis of her partial skeleton reveals breaks in her right arm, left shoulder, right ankle, and left knee—injuries that researchers say resulted from falling from a high perch such as a tree. Lucy likely died quickly, said John Kappelman, an anthropologist at the University of Texas at Austin, who published the findings Monday in the journal Nature. But several other researchers, including Lucy's discoverer, disagree. They contend most of the cracks in Lucy's bones are well documented and came after her death from the fossilization process and natural forces such as erosion, reports the AP.
The split highlights the difficulty of pinpointing a cause of death from fossilized remains. Scientists rarely know how early humans died because skeletons are incomplete (Lucy's is 40% complete) and bones tend to get crushed under sand and rocks. The Texas team examined Lucy's bones and used high-tech imaging. Kappelman said the scans revealed multiple broken bones and no signs of healing, suggesting the injuries occurred around the time of death. He reconstructed her final moments: The 3-foot-6-inch Lucy fell from at least 40 feet and hit the ground at 35mph. She landed on her feet before twisting and falling. Such an impact would have caused internal organ damage. Fractures on her upper arms suggest she tried to break her fall. Read more about the study's detractors here. (Read more Lucy stories.)