The process of determining which fractures were perimortem (those that appeared near the time of death) and which were postmortem (after death) was an incredibly difficult procedure. In agreement with most paleontological research, the team concluded that most fractures were indeed postmortem, and were likely generated by geological and zoological processes that afflict many examples of biological remains.
With the help of CT scanning techniques, the team reassessed a few of these fractures and concluded that they resemble those in human patients whom have undergone a form of high-energy trauma, like an impact event. These mostly occur today in those that are in an automobile accident or that fall from a significant height. With the invention of such vehicles still over 3 million years away, this means that they must have been caused by a vertical fall.
After these first shoulder fractures were located, the team went through the fossil bone-by-bone, joint-by-joint, until they matched them up with others that had previously gone unidentified. It was clear that a vertical deceleration event, as it’s technically known, was the only rational explanation for her death.
Lucy was not ideally adapted to living in trees nor was she the best two-legged walker, which means that either a terrestrial predator or a fall was always likely to finish her off. Being a small creature just 1.07 meters (3.5 feet) tall, concealing herself in trees would have been a good survival mechanism against any aggressors, but she may have also been foraging there.
Cracking the coldest case. UT Liberal Arts via YouTube
Precisely why she fell will likely always remain a mystery, and as there is only one example of her kind dying from falling from a tree, some may say that this doesn’t show that all A. afarensis were habitual tree-climbers. Still, it’s a distinct possibility, and one that this paleontological CSI study has brought to the fore once more.