Lucy, one of the best known ancestors of humans to ever roam the earth, may have died after a fall from a tree, University of Texas researchers said on Monday after studying her 3.18-million-year-old fossilized remains.
A high resolution X-ray CT (computed tomography) study of Lucy, a female hominid, indicates she suffered fractures to her right humerus not typically seen in fossils. There were also less severe fractures on the left shoulder and other compressive fractures throughout the skeleton, they said.
The injuries were consistent with those "caused by a fall from considerable height when the conscious victim stretched out an arm in an attempt to break the fall," according to the research from John Kappelman, a University of Texas anthropology and geological sciences professor, who consulted with Stephen Pearce, an orthopedic surgeon at Austin Bone and Joint Clinic.
"This compressive fracture results when the hand hits the ground during a fall, impacting the elements of the shoulder against one another to create a unique signature on the humerus," Kappelman said in a statement.
Lucy's skeleton was unearthed in 1974 in Ethiopia and since then researchers around the world have been looking at the fossil of the hominid to find its links to modern humans.
Kappelman speculated Lucy, who was about 3 feet, 6 inches (107 cms) in height, foraged and sought nightly refuge in trees.
Her injuries indicate she fell from a height of about of more than 40 feet (12 meters).
University of Texas researchers, including Kappelman, in 2009 completed the first high resolution CT scan of Lucy when the fossil toured the United States. The study resulted in some 35,000 CT electronic slices, which were then studied by university researchers.
"When the extent of Lucy's multiple injuries first came into focus, her image popped into my mind's eye, and I felt a jump of empathy across time and space," Kappelman said.
"Lucy was no longer simply a box of bones but in death became a real individual: a small, broken body lying helpless at the bottom of a tree."