“Lucy [might] have been run over by a stampede of larger animals, elephants or large bovids or antelopes, prior to her being washed into a water environment where fossilization began”. A new study based on an analysis of Lucy’s fossil by the university suggests she died after falling from a tree.
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Lead researcher Professor John Kappelman said he had first studied the skeleton – which is 40 per cent intact – when Lucy was brought to the U.S. in 2008.
University of Texas researchers, including Kappelman, in 2009 completed the first high-resolution CT scan of Lucy when the fossil toured the United States.
For decades, people who have spent their careers studying Lucy’s bones have debated how much time she spent in trees. “CT is nondestructive. So you can see what is inside, the internal details and arrangement of the internal bones”. “We see that the right arm is more severely fractured than the left”. A well-timed stampede while her corpse was still fresh could have caused the still-fresh bones to break this way.
But how did she come to rest in that shallow stream?
“Our hypothesis suggests that the fractures in Lucy’s shoulder were produced when she stretched out her arms in a last desperate attempt to break her fall”.
Additional “compressive fractures” in Lucy’s legs, forearms, pelvis and thorax, including the first rib – a hallmark of severe trauma – are also consistent with a fall, illustrating in a brutal, if prehistoric, way the ditty about how “the thigh bone’s connected to the hip bone”. It’s a scientific estimation of what Lucy may have looked like in life. But given her small size – 3-foot-6 and 60 pounds – she probably sought nightly refuge from predators by climbing into trees, the study suggests.
The scans revealed that the fracture in Lucy’s bone resulted from her hand hitting the ground after a fall, impacting her shoulder, and creating a unique mark on her humerus. A team led by Dr. Kappelman used CT scans to examine every bump and crack in her bones in an effort to reconstruct the individual hominin’s life – and death.
“It’s this jump of empathy across time and space that really allowed me to identify with her in a way that I hadn’t before”. “When I better understood the potential cause of her death, I could picture her broken body lying there at the foot of the tree”.
Kappelman reasons that because Lucy was both terrestrial and tree-dwelling, features that permitted her to move efficiently on the ground may have compromised her ability to climb trees. He found many more breaks, all consistent with a long fall. He’s had something like 10 specialists take a look at Lucy’s big break. This means that, “at a minimum, she climbed up a tree at night, slept there for some hours, and climbed down from that tree in the morning”, Kappelman said, adding that she might have sometimes foraged for food in trees too.
Writing in the journal Nature, researchers from the USA and Ethiopia describe a “vertical deceleration event” which they argue caused Lucy’s death. The 3-D files and other materials will be available at eLucy.org.
At that website, university officials even provide student activities ideal for educators – including printer-friendly, life-sized renderings of the ancient skeleton, a nine-piece puzzle, book marks and a fun word search.
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The research team’s conclusion that Lucy likely fell from a tree, specifically – a conclusion they came to by estimating the force of a fall from the heights at which chimpanzees and other primates typically nest in trees – only makes the study harder to swallow for some paleontologists. And UTCT was supported by three grants from the U.S. National Science Foundation.
