Professor Lee Burger is keeping mum on the latest hominid finds for now. (Oupa Nkosi, M&G)
This week six international scientists, with chest measurements of no more than 18cm, will climb down into a cave about 30m underground at an undisclosed location in the Cradle of Humankind.
The treasure? Hominid fossils that are "vulnerably exposed", says the University of Witwatersrand’s Professor Lee Berger. With Gauteng in its rainy season, time is of the essence. "I realised history would not judge me well if we delayed the excavation."
Berger shot to international fame following his 2008 discovery of Australopithicus sediba, a hominid with a mixture of human and ape characteristics. The find, which resulted in many papers and a cover story in the journal Science, put Southern Africa back on the palaeosciences map. "It proved there was more to be discovered," Berger says.
He describes the latest find – the first since he became National Geographic’s explorer-in-residence earlier this year – as "spectacular". He told journalists this week that the fossils were hominids, but he would not divulge any more details. He says the team first has to excavate and retrieve them.
But that is not a simple task: the cave where the fossils are is about 30m underground and can only be accessed through a small opening, hence the 18cm chest restriction.
When Berger put out a call on social media for "skinny anthropologists, biologists, cavers, not afraid of confined spaces", people thought he was joking. But within 10 days he had a list of 57 qualified candidates, from which he chose six, all women.
"If 1% of people on Earth go caving, these are the 1% of those people," he says, adding that the cavers had dropped everything to come from as far afield as Canada, the United States and Australia.
Although the fossils were only discovered by geologist Pedro Boshoff and his two assistants, Steve Tucker and Rick Hunter, at the beginning of last month, the six scientists – who will be supported by an above-ground team of 30 to 40 researchers, including Berger, who pats his ribcage ruefully – will explore the cave and bring the fossils to the surface within the next three weeks, he says.
He is aware of the danger of spelunking and says that "only a limited number of people will be allowed to the access-restricted site".
Updates on the excavation, called the Rising Star Expedition, can be found on National Geographic’s blog. National Geographic is a partner in the expedition.
"Our aim is to get the fossils out carefully, study them, compare them to other fossil material from around the world and then proceed to analyse and describe them," Berger says.
The team is hoping to publish its findings late next year.
Although A. sediba was found in 2008, a full catalogue of the fossils was only published last year, which makes the 2014 target ambitious.
However, unlike A. sediba, the new fossils will not have to be sent overseas for analysis. With increased attention focused on South African palaeoscience it has been designated as a geographic advantage research field and the department of science and technology this year launched a Palaeosciences Centre of Excellence at Wits.
"We have tremendous technology here," says Berger. "Our science has exploded. We have a micro CT scanner [which allows non-invasive scanning of fossils], 3D printers [which take the data from the scanner and make a model of the fossil]. We don’t need that [to send fossils overseas for testing] anymore."
In fact, technology is going to play a large role in the excavation, although Berger would not be drawn on what technology because, as he says, "we will be trying lots of different kinds, and some might not work".
"I will be in that cave, but not in person."