Monday, 28 April 2014

The first photographs of the Taung Child.

One of the most important breakthroughs in palaeoanthropology in the twentieth century was the discovery of the fossil known as the Taung Child, the first known specimen of Australopithecus, by Raymond Dart of the University of the Witwatersrand in South Africa in 1924. This discovery refocused efforts to find human ancestors on the African continent, where many such ancestors have subsequently been found. Prior to this researchers had been concentrating on eastern Asia, where the first specimen of Homo erectus, Java Man, had been found, or in Europe, where many people had been taken in by the Piltdown Man hoax.

In a paper published in the South African Journal of Science on 30 October 2012, Goran Štrkalj of the Department of Chiropractic at Macquarie University and Katarzyna Kaszycka of the Institute of Anthropology at Adam Mickiewicz University, present three early photographs of the Taung Child skull from the University of the Witwatersrand Archives, which were presented to the university by Dart’s family following his death in 1988, along with some notes on their authenticity.

Photograph of Raymond Dart holding the Taung skull. Štrkalj & Kaszycka (2012).

Two of the photographs have dates written on them, 1924 and 1925, however the handwriting is not Dart’s and may have been added considerably later. The photographs show the skull free of the surrounding matrix but with its jaw still attached, indicating that they must have been taken between December 1924, when Dart finished removing the skull from the matrix, and July 1929, when he was able to detach the jaw. It is likely that they were taken by Johannesburg Star photographer Len Richardson, a friend of Dart’s who was hired to take the photographs used in the original description of the fossil published in a paper in the journal Nature in February 1925, as well as subsequent publications (neither Dart himself nor the University of Witwatersrand owning a camera at the time).

Left lateral view of the Taung skull. Štrkalj & Kaszycka (2012).

However a plaster cast of the Taung Child skull is known to have been made by for the 1925 British Empire Exhibition, which opened in London in May 1925. The creation of this replica took considerable ingenuity on behalf of artisans in Johannesburg, where the making of such a replica had never previously been attempted. This replica was a subject of considerable pride to Dart and his colleagues, and it is quite conceivable that the replica would also have been photographed with great care.

Front view of the Taung Child skull. Štrkalj & Kaszycka (2012).

The original specimen of the Taung Child Skull is an endocast (infill of a mould left in the rock when the original bone weathered away) in calcite (limestone) crystals. It is subsequently a bright white in colouration. The photographs depict a rather duller greyish skull, a tone which is also seen in the replica skull, which is in the Natural History Museum in London, where it was donated by Dart in 1926 after the closure of the British Empire Exhibition.

Photograph of the presumed earliest plaster cast of the Taung skull, presented to the British Museum by Raymond Dart. Štrkalj & Kaszycka (2012).

While the 1925 plaster cast of the Taung Child skull is good, it is not as good as would be expected of a modern replica, and shows a poorer resolution of some features, notably the teeth, than the photograph, leading Štrkalj & Kaszycka to conclude that the photograph can be of the cast, and therefore that the photograph must be of the original skull.  They attribute the darker colouration seen in the photographs compared to the current skull as being down to incomplete cleaning of the specimen, Dart and Richardson being under pressure to produce the photographs ahead of the Nature publication (although these particular photographs were not used). This incomplete cleaning also suggests that the photographs were taken soon after the fossil was freed from the rock, in December 1924 or January 1925.

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