This week’s post deals with one of the most contentious issues in Australian archaeology: when (and why) did our megafauna go extinct? In this post, Sean Liddelow looks at why the site of Cuddie Springs is one of the most hotly contested archaeological sites in Australia.

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Australia was once a very different place. The familiar animals we all know well, such as the kangaroo and echidna, were, roughly 45,000 years ago, just a smaller variety of other much larger animals known as ‘megafauna’.  This list includes such unfamiliar monstrosities as the large flightless bird Genyornis (whom you certainly wouldn’t want to meet in a dark alley), the lumbering plant eater Diprotodon and Varanus priscus, the 600 kilogram goanna. All of these and many more once thrived in Australia’s harsh climate. However by around 40,000 years ago they were all gone, replaced by the smaller varieties of megafauna we see today (Field et al. 2008). How did this happen? The arrival of modern humans into Australia around 45,000 years ago (O’Connell and Allen 2004) certainly seems suspicious, as well as climate change brought about by ice ages over the last several hundred thousand years (Field and Dodson 1999). The archaeological site of Cuddie Springs is important in our understanding of megafauna. In recent decades this site has become the centre of controversy, mostly regarding to dating (Gillespie and Brook 2006). I will argue for the importance of the site and support its dating. I will also argue that Cuddie Springs is a very important site globally in understanding the consequences of mass extinctions.

The site of Cuddie Springs, in the middle of an ancient lakebed 200 metres in diameter, was first discovered in the late 1870s during the sinking of a well (Field et al. 2008). It was not until the 1930s that the site was excavated by palaeontologists. These initial excavations discovered a large array of extinct animals, including megafauna. In the early 1990s the site was again excavated; this time using modern archaeological techniques. A sequence of layers extending to a depth of 10 metres was discovered, with an unknown length of time. The upper 1.7 metres of this sequence was found to contain the remains of both extinct and currently living animals, amongst these flaked stone artefacts were discovered (which caused a predictable amount of excitement) dating back to around 36,000 years ago (Roberts et al. 2001; Field et al. 2008). These remains included the previously mentioned Genyornis and Diprotodon, to name a few. The association between the artefacts and the remains are not without its critics however.  

These critics, who include Richard Gillespie and Barry Brook, question the validity of the dates at Cuddie Springs (Gillespie and Brook 2006). Their arguments include sediment disturbance and the presence of hair and blood remains in the absence of bone collagen (A protein which is an important part of a mammal’s body). The disturbance of sediment is indeed an important factor in assessing the potential value of a site and how the site formed. The methods of dating used in these arguments include carbon-14 (obtained from charcoal) and thermoluminescence (TL), which measures the amount of time since sediment was exposed to sunlight. Gillespie and Brook claim that from analysis of the dating sequence that the dates of the site do not occur in the expected sequence, and therefore that the site is disturbed. The major implication of this is that the artefacts came from a different layer than the megafauna remains or vice versa. The argument regarding bone collagen rests on the assertion that the bone collagen should be present in the same layer in which hair and blood are found (as hair and bone collagen do not generally preserve well). This implies, as above, that the bone and hair are from different layers.

Judith Field responds to these criticisms and others aimed at the Cuddie Springs site (Field et al. 2008). She argues that the

optical luminescence dates (similar to TL) are in order (as the age increases with depth), and that the dates range from around 16,700 years ago to 36,000 years ago. She further argues that these are more reliable than the carbon-14 dates. Furthermore the stone artefacts are different between each layer, implying a clear change over time and an undisturbed site. There are also over changes, include changes in pollen amounts and the megafauna remains, which shouldn’t be obvious at a disturbed site. It is then argued that the assumption that the collagen protein should be preserved in the same layer as the hair is flawed, as we are still limited in our knowledge of just how hair remains (and the blood remains also found in the layer) are preserved. Another point in the argument is that the presence of manganese in the site stops the collagen from preserving, whilst the blood is preserved in poor amounts as would be expected. Thus it can be seen that some of the arguments used by Gillespie and Brook do not hold to scrutiny and that the site should retains its importance.

It should now be clear to all those who are still reading that the Cuddie Springs site is extremely important in our understanding of megafauna and the early human occupation of Australia. Any evidence of interaction between the two is vital to unravelling the mystery of just how the megafauna went extinct. Was it humans? Climate change? Both? The general consensus in recent years is starting to point towards the latter, but the issue is still far from certain. The interpretation of sites such as Cuddie Springs will surely contain the answer. I believe that it can be argued convincingly that the dates of Cuddie Springs are reliable (Field et al. 2008) and therefore that the site is of global importance, as it provides a very rare example of humans and megafauna interacting. For today the subject of mass extinctions is increasing relevant, as a great amount of species are becoming extinct every year. Through understanding the past extinctions and how these occurred, we should get a greater understanding of what we can do to help ease and forestall extinction events in the future.

Further Reading

• The article by Field et al. cited in this post; Chronological overlap between humans and megafauna in Sahul (Pleistocene Australia–New Guinea): A review of the evidence, has a good summary of the Cuddie Springs site and a response to the criticism associated with it.

• Another article by Wroe et al; Climate change frames debate over the extinction of megafauna in Sahul (Pleistocene Australia-New Guinea), is an excellent (and recent) review of megafauna extinction in Australia.

• A recent news article in New Scientist, Megafauna extinction: DNA evidence pins blame on climate change, details recent research in the field of megafauna.

References

Field, J. and Dodson, J. 1999 Late Pleistocene Megafauna and Archaeology from Cuddie Springs, South-eastern Australia. Proceedings of the Prehistoric Society 65:275-301.

Field, J., M. Fillios and S. Wroe 2008 Chronological overlap between humans and megafauna in Sahul (Pleistocene Australia–New Guinea): A review of the evidence. Earth Science Reviews 89:97-115.

Gillespie, R. and Brook, B.W. 2006 Is there a Pleistocene archaeological site at Cuddie Springs? Archaeology in Oceania    41:1-11.

O’Connell, J.F. and Allen, J. 2004 Dating the colonization of Sahul (Pleistocene Australia–New Guinea): a review of recent research. Journal of Archaeological Science 31:835-853.

Roberts, R.G., T.F. Flannery, L.K. Ayliffe, H. Yoshida, J.M. Olley, G.J. Prideaux, G.M. Laslett, A. Baynes, M.A. Smith, R. Jones and B.L. Smith 2001 New Ages for the Last Australian Megafauna: Continent-Wide Extinction about 46,000 Years Ago. Science 292(5523):1888-1892.