In 1994, paleoanthropologist Ronald Clarke uncovered foot bones in Sterkfontein Cave northwest of Johannesburg, South Africa, that he believed may belong to monkeys.
Clarke spent the next 20 years excavating the site to reveal 90% of a far more fascinating skeleton.
The skeleton, dubbed Little Foot, was initially thought to be the most complete example of an Australopithecus fossil ever found. Australopithecus were early humans from 2 million to 4 million years ago.
Little Foot may have been the first to walk
The skeleton was dated to be 3.67 million years old, belonging to an elderly female approximately 130 centimeters tall. The discovery is especially important because it is the first example of a skeleton from this period with intact ribs.
This means that researchers can analyze how Little Foot may have walked. Her legs were found to be longer than her arms, distinctly opposite from her predecessor the ape-like Ardipithecus species.
Researchers argue for a new species classification
“This hominin, for the first time in the fossil record, had longer lower limbs than upper limbs, like ourselves."
"This is an important finding, as the slightly older hominid Ardipithecus, which came before Australopithecus, had longer arms than legs – more like other great apes such as the gorilla,” said Professor Robin Crompton, Honorary University of Liverpool Research Associate in Musculoskeletal Biology.
This allowed the researchers to argue that Little Foot is actually an entirely new species. Clarke, the skeletons finder classifies Little Foot as an A. Prometheus.
Decades of painstaking work pays off
A series of papers published about the analysis of Little Foot's skeleton have provided extensive evidence that Little Foot might be a distinct interim species that developed from a tree-climbing hominin to walking on two legs.
The analysis of the skeleton is yet to be peer-reviewed but the latest paper from the research team, titled :
'Functional Anatomy, Biomechanical Performance Capabilities and Potential Niche of StW 573: an Australopithecus Skeleton (circa 3.67 Ma) From Sterkfontein Member 2, and its significance for The Last Common Ancestor of the African Apes and for Hominin Origins’, can be read online here.
The skeleton took so long to remove from its location due to the bones very delicate structure. The hard rock around the skeleton makes excavation a painstaking process.
“The fossilized bone is actually softer than the matrix,’ says Crompton. “It’s been an absolute devil to get it out.” Research and analysis will continue on Little Foot to start to understand the world she lived in.
Already the research team has been able to offer some insights into Little Foot's life.
“Although Little Foot’s legs were longer than her arms, they had not yet achieved the great relative leg length found in humans. Thus, she would not have been as good at carrying objects as we are. However, she would have been much better at climbing trees than modern humans," Professor Compton offered.
“It is most likely that she would have resided in an area that was a mix of tropical rainforest, broken woodland and grassland, through which she would roam around. She would have lived primarily on forest fruits and leaves”.