Facts about the most famous human ancestor: Lucy read more at here www.spinonews.com/index.php/item/733-facts-about-the-most-famous-human-ancestor-lucy

Researchers at University of Texas at Austin founded the most famous fossil of a human ancestor Lucy, a 3.18-million-year-old specimen of Australopithecus afarensis is among the oldest, most complete skeletons of any adult, erect-walking human ancestor.

John Kappelman and Richard Ketcham, professors at UT Austin anthropology and geological sciences studied Lucy.

The fossil replacing to the High-Resolution X-ray Computed Tomography Facility (UTCT), to scan materials as solid as a rock and at a higher resolution than medical CT. Using this machine, they scanned all of her 40-percent-complete skeleton to create a digital archive of more than 35,000 CT slices. CT is nondestructive, you can see what is inside, the internal details and arrangement of the internal bones.

After studying Lucy, kappelman noticed something exceptional, the right humerus was fractured in a manner not normally seen in fossils, preserving a series of sharp, clean breaks with tiny bone fragments and slivers still in place.  

Kappelman said, “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.”

Dr. Stephen Pearce, an orthopedic surgeon at Austin, confirmed the injury caused by a fall from considerable height when the conscious victim stretched out an arm in an attempt to break the fall. Without any evidence of healing, Kappelman concluded the breaks occurred perimortem, or near the time of death.

The question remained: How could Lucy have achieved the height necessary to produce such a high velocity fall and forceful impact?

Kappelman declare that because of her size about 3 feet 6 inches and 60 pounds Lucy probably foraged and sought nightly refuge in trees. Comparing with chimpanzees Lucy probably fell from a height of more than 40 feet, hitting the ground at more than 35 miles per hour.

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.

In addition to the study, the Ethiopian National Museum provided access to a set of 3-D files of Lucy's shoulder and knee for the public to download and print so that they can evaluate the hypothesis for themselves.