COEXISTENCE OF HUMANS AND MEGAFAUNA IN AUSTRALIA



Troublesome Questions
In 1830 Mr. Rankin tied a rope around a projection out of a rock face in order to lower himself into Wellington Cave (Horton, 1980). The projection turned out to be the bone of a giant extinct marsupial. It was to be the first discovery of a great range of giant marsupials. Were these animals extinct?? Horton (1980), describes how Leichhart believed that on his journeys to northern Australia he would find Diprotodon still roaming over the land. We now know that he was probably only about 20,000 years to late (Flood, 1995). In general, all the animals greater than 40 kg in body weight became extinct at the end of the last Ice Age. By the mid 19th century scientists had already begun to postulate about the disappearance of these animals, and today it remains one of the most controversial subjects presented to man, (Horton, 1980).
Australia was not the only country to experience extinctions of large animals, (Martin, 1984). At the end of the last glacial period nearly every continent experienced extinctions of large animals. Animals like the Mammoth, giant ground sloths, and mastodons were roaming the Americas. Northern Eurasia featured woolly mammoths, giant deer, hippopotamus and straight tusked elephants. Of all the continents, it could be argued that Australia lost some of the most distinctly unique fauna in the world. The popular opinion for the cause of extinction is the \'blitzkrieg\' hypothesis, which is held by such researches as Paul Martin in his controversial article "Prehistoric Overkill: The Global Model". This states that humans are directly responsible for these extinctions world wide. The Problem with this model for Australia is that humans may have arrived on this continent well before the extinctions took place (Flood, 1995). On other continents the extinctions coincided almost exactly with the arrival of man (Martin, 1984).
European man was not the first member of the genus Homo to set foot on the Australian continent. There is evidence to suggest that Aboriginal people have been walking on Australian soil for many tens of thousands of years (Flood, 1995). Whether or not Aboriginal people interacted with the large now extinct beasts is hard to determine. Did an overlap in time exist between humans and these large beasts? Is there any evidence that humans actively hunted them, and if they did, is it possible that they drove them to extinction?

Land of the Giants
During the late Pleistocene, the last glacial period spanning roughly 100,000 years, the faunas were completely different to those that are represented today. The most pronounced difference is body size. The term \'megafauna\', meaning \'large animals\' has been used to describe late Pleistocene animals throughout the world. We know that most species of mammals greater than 60 kg in bodyweight became extinct at the end of the Pleistocene. \'Megafauna\' is not a taxonomic group nor is there a standard definition. Generally, the term megafauna describes an animal that weighs 40 kg or more, but in Australia that would result in including four species of living kangaroos (the grey, red, antilopine and wallaroo) and probably excluding the extinct carnivore Thylacoleo and the smaller Sthenurus (short faced kangaroo) (Murray, 1991 in Vickers-Rich et al., 1991). Horton, (1984) came up with a tedious but more precise definition for the Australian megafauna: \'Animals that became extinct before the Holocene and are large, either in an absolute sense or relative to other members of some taxonomic rank, or are part of a taxonomic category all of whose members became extinct and some of whose members are large.\'
Fifteen genera and roughly forty-one species of mammalian megafauna became extinct in Australia at the end of the Pleistocene (Flannery, 1990). It should be noted that this essay is not going to consider the many large birds (e.g. Genyornis) and reptiles (e.g. Megalania prisca) which also became extinct during the Late Pleistocene. If these non-mammals are added to the tally of extinctions, the number of megafaunal genera extinct goes up to nineteen (Flood, 1990).
A typical mammalian megafaunal community consisted of a variety of forms, such as: Zaglossus; Marsupial Lion Thylacoleo; giant wombats Phascolonus; long-beaked echidnas; the Marsupial Tapir (Palorchestidae); Diprotodon (Diprotodontidae); and some especially large morphs of the living Macropus (Macropodidae), (Murray, 1991 in Vickers-Rich et al., 1991). The