A digital reconstruction of the face of the millennia-old fossil ‘Little Foot’ offers fresh insight into early human evolution, according to a study.

The study, led by researchers at Wits University in Johannesburg, South Africa, used advanced 3D scanning technology to digitally reconstruct the fossilised face of Little Foot.

First discovered in South Africa’s Sterkfontein Caves in 1994, Little Foot is one of the most complete skeletons of an early human, or hominin, ever found. Since then the skeleton has been much studied; however, investigation of the face has been challenging due to distortion caused by millions of years of geological processes. Researchers have found it impossible to correct these distortions using physical reconstruction methods. 

Partnering with the UK’s national synchrotron science facility, Diamond Light Source, the research team used high‑resolution synchrotron scanning and advanced virtual reconstruction techniques to digitally reassemble Little Foot’s facial bones.

Using a 3D scanning technique known as synchrotron X-ray micro-computed tomography on the I12 beamline, the team captured high-resolution internal and external structural data from the fossil without causing damage.

With the resulting digital reconstruction they could then compare Little Foot’s fossilised face with other extant great apes, as well as with three other Australopithecus fossils, a genus of early human ancestors that lived in Africa between about 4 million and 2 million years ago. These included a younger specimen from South Africa and two Ethiopian specimens. 

Analysing nine linear facial measurements between these fossils, the results show that the overall size of the face, the shape and dimensions of the eye sockets, and the general facial architecture of Little Foot more closely resemble the East African fossils than the younger South African comparative specimen.

“This pattern is unexpected, given the geographic origin of Little Foot, and suggests a more dynamic evolutionary history than previously assumed,” said Dr Amélie Beaudet, a previous postdoctoral fellow and current honorary researcher at Wits University.

Little Foot, for instance, may represent a lineage closely related to East African populations, while later South African hominins developed more distinct facial features through local evolutionary processes.

The study also identified evidence of selective pressures acting on the orbital region, which may relate to changes in visual capacity and ecological behaviour.

“Besides the fact that our study, limited to one anatomical region and a couple of comparative fossil specimens, provides additional data on the affinities between Australopithecus populations across Africa, we demonstrate that the orbital part of the face has possibly been under evolutionary pressure at that time,” said Beaudet.

The hominin face evolved over time to become less projected and more gracile, but the timing and mechanisms driving these changes remain unclear. This study contributes data towards answering these questions. 

“Rather than viewing early hominin evolution as occurring in isolated regions, the study supports the idea of Africa as a connected evolutionary landscape, with populations adapting to ecological pressures while remaining linked through shared ancestry,” said Professor Dominic Stratford of Wits University, who is also director of research at the Wits Sterkfontein Caves.

As further digital reconstructions are completed, the researchers hope to further refine our understanding of how early hominins moved, interacted and diversified across Africa.

“The face is only part of the story. Other parts of the skull, especially the braincase, remain distorted by plastic deformation and will require similar digital reconstruction to better understand brain size and organisation in this early hominin,” said Beaudet.