They conclude that Lucy died fallen from a tree

2016/08/29 Galarraga Aiestaran, Ana - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Eboluzioa
• Paleontologia
• Arkeologia

Although 42 years have elapsed since Lucy's fossil bones were discovered, archaeologists continue to emerge new data on one of our best-known ancestors.

On this occasion, high-resolution computed tomography has given them the opportunity to know that Lucy died collapsed from height, probably from a tree. According to the researchers, this reinforces the hypothesis that their species (Australopithecus afarensis), despite being bipedal, also circulated through the trees.

Among the fossils of human ancestors, the Lucy skeleton is one of the oldest (3.18 million years) and most complete (40% of the total). To learn how Lucy died, researchers from the Universities of Texas and Addis Ababa have studied these bones, both directly and through computed tomography.

This technique allows to observe the structure of the bones in three dimensions in detail, without causing any damage to the bones. Thus, they discover that their ruptures did not occur after death, but were alive or dead. They have even come to the conclusion that they fell high and broke with a strong blow.

Based on bone fractures

According to the researchers, one of the bones shown below is the humerus on the right. In fact, they have seen that it broke due to the compression that the bone suffers after a fall, hit the ground and stretch the arms to protect the body and place the hands on the ground. This hypothesis coincides with the fracture of the right scapula and other bones and joints.

The bones on the left also suffered the impact of the fall, but to a lesser extent, which, according to the researchers, would indicate that it fell to the right. In the pelvis, spine, neck, skull and maxilla, fall remains have also been seen. In addition, they have shown that they fossilized how the bones were broken, that is, Lucy did not form, died by fall.

Researchers have also calculated Lucy's height and speed of fall. With a length of one meter and a weight of 27 kg, they estimate that it fell from 12 meters and that the ground shot at 60 kilometers per hour. Even more: Based on the habitat and lifestyle of the species Australopithecus afarensis, they believe it would fall from a tree.

In fact, the director of the research, John Kappelman, believes that Lucy and his companions were as arboreal as the earthlings, but that being bipedal prevented them from a certain measure, the ability to walk in the trees. Therefore, they would probably have a higher risk of falling than tree species.