After 20 years of slow and careful excavation, the world’s most complete skeleton of an ancient human ancestor has just been discovered.

It belongs to the genus Αustralopithecus, and is 3.67 million years old. It is by far the most complete hominin skeleton in the world at over 1.5 million years old, and the oldest hominin skeleton ever found in South Africa. Its name is “Little Foot” – because the discovery of the skeleton began with four small foot bones.

“This is one of the most remarkable fossil discoveries made in the history of human origins research and it is a privilege to unveil a find of this importance today,” said Ron Clarke, from the Institute of Evolutionary Studies at the University of the Witwatersrand in johannesburg. who discovered the skeleton 20 years ago.

Little Foot is not the oldest hominin skeleton ever found: that honor goes to Αrdi, a hominin who lived in Ethiopia 4.4 million years ago. But Little Foot is significantly more complete than Αrdi and can be more informative.

Little Foot is expected to be able to provide a wealth of information about our early Αustralopithecus ancestors: how they moved, how their skeletons were put together, what they looked like.

Isotope analysis of fossilized tooth enamel may even help fill in some gaps about the environment Little Foot lived in and the food he ate.

Little Foot is relatively small, measuring about 135 centimeters (4 feet, 4 inches). She is a female skeleton, as determined by her pelvic structure, face, and teeth. The bones are believed to have belonged to a girl who died falling down a shaft into the caves below.

Importantly, her presence suggests that hominids spread further across Africa than previously thought, and she is the first skeleton to allow a comparison between arm length and leg length in a single individual.

Her legs were longer than her arms, which shows that she is much more like humans than apes. She walked upright and probably lived in the trees.

The fossilized skeleton was first found in the Sterkfontein Caves, not far from Johannesburg, more than 20 years ago.

Clarke was alerted to its presence in 1994 by foot and leg bones that had been gouged out of the rock by lime miners years earlier, but it was not until 1997 that the remainder of the skeleton was found, deep within the cave.

It was embedded in a concrete-like rock called a breccia, so digging it out of the cave was slow work. Large blocks of the breach, in which the skeleton was embedded, were painstakingly removed from the cave. It took until 2012.

Meanwhile, in a laboratory, a team of experts carefully removed the gap that surrounded the skeleton.

“My assistants and I have worked painstakingly cleaning the bones from the breccia blocks and reconstructing the full skeleton to this day,” Clarke said.

“The process required extremely careful excavation in the dark environment of the cave. Once the upward-facing surfaces of the skeletal bones were exposed, the gap in which their lower parts were still embedded had to be carefully undermined and removed in blocks for further cleaning in Sterkfontein’s laboratory.”

Researchers around the world are currently studying the skeleton to learn more about this amazing specimen, and we can expect peer-reviewed studies in the coming years.