Soft tissues rarely preserve in the fossil record, rather scientists are mostly left with just the skeletal material. Yet, muscles animate the body. They allow an animal to move, walk and run. To understand how an extinct species may have moved, scientists first need to reconstruct the missing soft tissues of the skeleton with an understanding of volume and the composition within the body. In the new study, University of Cambridge’s Dr. Ashleigh Wiseman 3D-modeled the leg and pelvis muscles of Australopithecus afarensis using MRI and CT scans of ‘Lucy,’ the famous fossil specimen discovered in the Hadar region of Ethiopia in the 1970s.
Australopithecus afarensis was an early human species that lived in East Africa over 3 million years ago.
Shorter than us, with an ape-like face and smaller brain, but able to walk on two legs, it adapted to both tree and savannah dwelling — helping the species survive for almost a million years.
Named for the Beatles classic Lucy in the Sky with Diamonds, Lucy is one of the most complete examples to be unearthed of any species of Australopithecus — with 40% of her skeleton recovered.
Dr. Wiseman was able to use recently published open source data on the Lucy fossil to create a digital model of the 3.2 million-year-old hominin’s lower body muscle structure.
She recreated 36 muscles in each leg, most of which were much larger in Lucy and occupied greater space in the legs compared to modern humans.
For example, major muscles in Lucy’s calves and thighs were over twice the size of those in modern humans, as we have a much higher fat to muscle ratio. Muscles made up 74% of the total mass in Lucy’s thigh, compared to just 50% in humans.
Paleoanthropologists agree that Lucy was bipedal, but disagree on how she walked. Some argue that she moved in a crouching waddle, similar to chimpanzees when they walk on two legs. Others believe that her movement was closer to our own upright bipedalism.
Research in the last 20…
Read the full article here