In June 1997, a former tour guide at the Sterkfontein Caves, Stephen Motsumi, was trying to find a connecting piece to a shin bone on a muddy wall in one of the chambers.
With only his headlamp illuminating the pitch-black cavern, he and Nkwane Molefe gently brushed aside the soil and mud, exposing a white patch in the rock that matched the cast he held in his hand.
Motsumi, now in his 60s and living in Brits, didn’t immediately realise he had unearthed a vital clue that would lead to the discovery of the world’s oldest almost complete skeleton of a human ancestor (at about 3.67‑million years old), nicknamed Little Foot, after just a day and a half of searching.
World-renowned palaeontologist Professor Ron Clarke told the Mail & Guardian this week: “I drove into the site and he [Motsumi] came out to meet me in the car, and said: ‘Oh, you know that bone you asked us to look for? I think we’ve found it.’ He was very deadpan, so I thought: ‘Well, maybe he thinks he’s found it.’
“The chances of finding it was like looking for a needle in a haystack,” Clarke added. “And the fact that they found that contact opened up the potential to find the whole skeleton.”
The Little Foot skeleton, which scientists believe is of a 30-year-old, 1.5m-tall woman, was found 10m deep.
In 1994, Clarke was digging around in a box filled with animal bones at Sterkfontein when he discovered what appeared to be an ankle bone of one of man’s oldest relatives, Australopithecus prometheus. Three years later, he happened on a broken shin bone that led him to suspect there may be an entire skeleton waiting to be excavated.
Although Little Foot belongs to the same zoological hominid group as humans, it is not a Homo species.
The skeleton, which took 20 years to excavate, clean and reconstruct, was unveiled at the University of the Witwatersrand’s Evolutionary Studies Institute on Wednesday by Clarke and his team.
When Motsumi saw the skeleton in its entirety, he was amazed and re-energised: “It was a great, great moment for me … But there’s still a lot of work to be done … Palaeontology is so exciting, not only because of the hominids but because of everything you find. My wish is to have my job again for another five years,” he told Christa Kuljian, author of Darwin’s Hunch.
Motsumi had been employed as a tour guide in Sterkfontein but left the job and went to work in the field alongside palaeontologist Alun Hughes and, later, Clarke.
On Wednesday, as Clarke grabbed the world’s attention while introducing Little Foot, he was at pains to credit Motsumi and Molefe.
“Stephen and Nkwane were very, very meticulous. They were dedicated to what they did. A lot of people might have thought we’ll just have a superficial look and that’s it. But they went on looking intensely for one-and-a-half days,” Clarke said.
He told Kuljian that the late Wits professor Phillip Tobias was also determined to credit the pair for their discovery. The acknowledgement of black professionals in the palaeontological sciences only started at the turn of democracy in South Africa, Kuljian explains in her book.