By Ashley Strickland, CNN
(CNN) — Scientists can now come face to face with an early human ancestor nicknamed Little Foot who lived 3.67 million years ago, thanks to digital reconstruction technology.
Renowned paleoanthropologist Ronald Clarke identified four tiny bones in the University of the Witwatersrand’s museum collection and went on to discover Little Foot’s nearly pristine fossil in the 1990s in the Sterkfontein Caves northwest of Johannesburg, South Africa. Full excavation of the remains took a painstaking 20 years, but it was worth it.
At 90% intact, the specimen is the most complete known skeleton belonging to Australopithecus, chimpanzee-like ancestors who were able to walk upright on two feet but also adept at climbing trees to escape from predators like sabre-toothed cats.
The skeleton represents the oldest evidence of human evolution in southern Africa, said Dr. Amélie Beaudet, an honorary researcher in the School of Geography, Archaeology and Environmental Studies at the University of the Witwatersrand, Johannesburg, who has studied the fossil unearthed from the Cradle of Humankind World Heritage Site for years.
However, Little Foot’s skull, which became crushed as surrounding cave sediment grew heavier and shifted over time, has been difficult to study. The skull distortion was so extensive that physical reconstruction wasn’t possible.
Now, Beaudet and her colleagues have digitally rearranged the facial bones to their rightful places, providing a clearer look at Little Foot’s face — and hinting at features that may be shared across the human family tree.
“Only a handful of Australopithecus fossils preserve an almost complete face, making Little Foot a rare and valuable reference point,” said Beaudet, lead author of the study published Monday in the journal Comptes Rendus Palevol, in a statement. “Little Foot’s face preserves key anatomical regions involved in vision, breathing and feeding, and its skull will offer further key elements for understanding our evolutionary history.”
Reconstructing a fossilized face
Little Foot’s fossilized remains left South Africa for the first time so researchers could capture precise images of the inner structures of her face, which had never been seen.
The skull was shipped to England so it could go through high-resolution scanning at the Diamond Light Source synchrotron, located at the Harwell Science and Innovation Campus in Oxfordshire.
The machine scanned the skull using bright, nondestructive X-rays, generating over 9,000 high-resolution images and terabytes of data. A supercomputer at the University of Cambridge processed the images and rendered the facial bones in 3D, enabling a digital reconstruction of the face.
Realigning the bones virtually in their correct anatomical positions revealed the upper part of the face for the first time, including the orbital region where Little Foot’s eyes would have been.
Her reconstructed face was then compared with three other Australopithecus specimens, including one from South Africa and two from Ethiopia, as well as modern great apes.
The size of Little Foot’s face fell between that of a gorilla and an orangutan, while the shape was closer to what is seen in orangutans and bonobos.
The team was surprised to find that the face size, as well as the shape and measurements of her eye sockets, were also more similar to the East African Australopithecus fossils, despite the fact that Little Foot was found in South Africa.
“All this shows the complexity of the patterns of variation in the genus Australopithecus and the latter’s proximity to the great apes,” said Dr. Zeray Alemseged, Donald N. Pri