New fossil autopsy say that "Lucy" fell from tree

Lucy, an ancient ambassador of a prehuman species called Australopithecus afarensis, fell from a tree in Ethiopia nearly 3.2 million years ago, killing one of humankind's most famous ancestors, believe researchers at the University of Texas based on a detailed digital examination of the fossil.

Some of the damage to Lucy’s 3.2-million-year-old partial skeleton most likely occurred when she fell from a height of 13 meters or more, say paleoanthropologist John Kappelman of the University of Texas at Austin and his colleagues.

 Kappelman was the lead author of the study on Lucy.

Bone breaks from head to ankle fit a scenario in which Lucy dropped the equivalent of least four to five stories, landing feet first before thrusting her arms out in an attempt to break her fall, Kappelman says.

Tellingly, the ancient female’s right shoulder blade slammed into the top of her upper arm bone, Kappelman says. The shoulder end of Lucy’s arm bone displays sharp breaks, as well as bone fragments and slivers forcibly driven into the shaft.

 Paleoanthropologist Donald C. Johanson, who helped find the bones in the 1970s, told the Times that it was more likely that the fractures occurred long after her death, as her skeleton was buried under sand rather than a tree fall.
Paleoanthropologist Tim White of the University of California said that Cracks and breaks throughout Lucy’s skeleton occurred after her death.

Bone cracking was caused by fossilization and by pressure on fossils embedded in eroding sandstone. Fossilization-related breakage much like Lucy’s including extensive shoulder-joint damage appears on the bones of a variety of non climbing animals, including gazelles, hippos and rhinos.