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Thursday 7 December 2017

"Little Foot", the oldest complete hominin fossil makes its appearance

'Little foot', a 3.67 million year old australopithecine hominin made its formal debut at the University of the Witwatersrand in Johannesburg on December 6. Originally discovered in the mid-1990s, it has taken two decades to remove the fossil from the surrounding rock and prepare it. What makes 'Little foot' so remarkable is that it is the oldest complete hominin fossil ever found.

The fossil evidence for human evolution, which shows an unmistakable trend towards bipedality and increasing cranial capacity over time was compelling well before this discovery, but both its age and near-complete status make this one of the greatest discoveries in palaeoanthropology. It also underscores the point, one that should be obvious by now, that denial of the fact of human evolution is simply no longer credible.

Over two years ago, I commented on 'Little foot', noting that:

We also know that it is quite old. [Professor Ron]Clarke and his colleagues have published an article in Nature [1] in which they state that 'Little Foot' at around 3.67 million years old. If this date is confirmed, this would place 'Little Foot' on a line ancestral to our species. Irrespective of the date, not only do we have yet another transitional fossil given its primitive skull, its more modern hands, and feet with ape-like and human-like features [2] but we have an astonishingly complete fossil. [1]
How complete? Take a look:

   MUJAHID SAFODIEN/AFP/Getty Images (Source)

The fossil was found over a three year period between 1994-1997 at the Sterkfontein caves, 40km north-west of Johannesburg in a process that could only be described as painstaking:
After lying undiscovered for more than 3.6 million years deep within the Sterkfontein caves about 40km north-west of Johannesburg, Clarke found several foot bones and lower leg bone fragments in 1994 and 1997 among other fossils that had been removed from rock blasted from the cave years earlier by lime miners. Clarke sent his assistants Stephen Motsumi and Nkwane Molefe into the deep underground cave to search for any possible broken bone surface that might fit with the bones he had discovered in boxes. Within two days of searching, they found such a contact, in July 1997.
Clarke realised soon after the discovery that they were on to something highly significant and started the specialised process of excavating the skeleton in the cave up through 2012, when the last visible elements were removed to the surface in blocks of breccia. "My assistants and I have worked on painstakingly cleaning the bones from breccia blocks and reconstructing the full skeleton until the present day," says Clarke. [2]
Just how painstaking?
The process of removing the bones from the caves was painstaking, as the fossil had "very fragile bones", which were "extremely soft" and "buried in a natural concrete-like material", he added.

"We used very small tools, like needles to excavate it. That's why it took so long. It was like excavating a fluffy pastry out of concrete," Prof Clarke said. [3]
More on the discovery and recovery of 'Little foot' can be found in the short video below:



Early next years, several papers will be published. 2018 looks like it will be a stellar year for palaeoanthropology.

References

1. http://christadelphianevolution.blogspot.com.au/2015/04/meet-latest-member-of-human.html
2. University of the Witwatersrand. (2017, December 6). Litte Foot takes a bow: South Africa's oldest, and the world's most complete Australopithecus skeleton ever found, introduced to the world. ScienceDaily. Retrieved December 7, 2017 from www.sciencedaily.com/releases/2017/12/171206100104.htm
3. http://www.bbc.com/news/world-africa-42250530