Taung Heritage Site: 17 June 2012

The early hominid fossil site of Taung is one of the ‘Big Five’ Plio-Pleistocene sites in South Africa, and is historically the first australopithecine site to be recognized. The discovery and recognition of the Taung skull fossil is a fascinating story, and is detailed in Raymond Dart’s Adventures with the Missing Link (Dart and Craig, 1959). In December 1924, a crate of breccias blocks (rocks containing fossils) from the lime mine at Taung was delivered to Raymond Dart at the University of Witswatersrand in Johannesburg. In it, he discovered a small skull of a juvenile hominin, which became nicknamed “the Taung child”. The fossil preserved much of the facial skeleton, mandible, and endocast (an impression of the brain on the inner surface of the skull). Dart quickly published a report on his find in February 1925 and proposed that it represented a new hominin species, Australopithecus africanus – or ”the Southern ape from Africa” (see photo of the Taung skull). More recent research has determined that the fossil is more than 2 million years old.

In his report, Dart stated “the specimen is of importance because it exhibits an extinct race of apes intermediate between living anthropoids [apes] and man [emphasis original]” (1925, p. 125). At the time, many scientists would not accept that humans evolved from an ape-like ancestor and the skull’s significance was largely ignored for several decades. But it was this challenge to Dart’s interpretation of the Taung fossil that led other researchers such as Robert Broom to explore other South African lime mines for further fossil traces of human ancestry.

One of the original published (1925) photos of the Taung Skull in lateral view, showing the facial skeleton to the right, and the brain endocast to the left.

We visited the Taung limeworks near the town of Buxton in the North West province. The site, which was designated a National Heritage Site in 2002 (see plaque photo), is quite large and was an active mine during the 1920s. It was later systematically excavated by paleoanthropologists from the University of California in the 1940s, and from the University of Witswatersrand between 1988 and 1992. Both the mining and excavations resulted in extensive dumps that surround the area of the site from which the skull is thought to derive. However, the exact location at which the skull was found can only be approximately reconstructed from mine records and historical documents – after all, it was only recognized after it arrived in Johannesburg in a wooden crate!

The Taung site is both a National, and World Heritage Site. This plaque provides the essential information about the site, and the Taung Skull fossil.

The Dart and Hrdlička pinnacles, and the monument marking the possible location of the Taung Skull.

How the Taung juvenile died, and became deposited in the fossil record is not certain. One hypothesis is based on taphonomic evidence from the fossil and associated specimens in the deposit, including possible raptor claw marks on the skull. This model suggests that a large bird of prey snatched the child from the air, and the skull was subsequently left below the raptor roost (e.g., Berger and McGraw, 2007). Cases demonstrating this hunting technique by large raptors are documented for other primate species.

Another hypothesis is palaeoenvironmental in nature and is based on deposits of tufa present at the site. Tufa is a calcium-carbonate rock produced when organic matter settles in still or slow-moving water with algal blooms, and builds up into massive deposits over time. Animals may be incorporated into such deposits if they die in or near the water source – thus, it may be that the Taung child died of natural or unknown causes, fell into the stagnant water, settled, and fossilized (McKee, 1993). If the exact location of the deposit from which the Taung fossil was derived were known, these different hypotheses could be tested more rigorously, and a firmer conclusion might be possible.

The Taung site is where the modern field of palaeoanthropology began, because it produced the first early hominid fossils from Africa, a discovery which eventually transformed the field, and our view of our own evolutionary history. For us, it is also significant that the site was located at an old lime mine – and this is one of the reasons that we are currently in the field, attempting to locate other such lime mines in new areas. Who knows what future discoveries these sites might reveal?

REFERENCES

Berger, LR and McGraw, WS. 2007. Further evidence for eagle predation of, and feeding damage on, the Taung child. South African Journal of Science 103:496-498.

Dart, RA. 1925. Australopithecus africanus: the man-ape of South Africa. Nature 115:195-199.

Dart, RA and Craig, D. 1959. Adventures with the Missing Link. New York: Harper & Brothers.

McKee, JK. 1993. Formation and geomorphology of caves in calcareous tufas and implications for the study of the Taung fossil deposits. Transactions of the Royal Society of South Africa 48(2):307-322.

-KL Lewton and KL Kuykendall

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