Analysis of oxygen and carbon isotopes from teeth of megafauna indicate the regional climates at the time of extinction were similar to arid regional climates of today and that the megafauna were well adapted to arid climates. However, these results were subsequently disputed, with another study showing that 50 of 88 megafaunal species have no dates postdating the penultimate glacial maxiumum around 130,000 years ago, and there was only firm evidence for overlap of 8-14 megafaunal species with people. The dates derived show that all forms of megafauna on the Australian mainland became extinct in the same rapid timeframe-approximately 46,000 years ago -the period when the earliest humans first arrived in Australia (around 70,000~65,000 years ago long chronology and 50,000 years ago short chronology). New evidence based on accurate optically stimulated luminescence and uranium-thorium dating of megafaunal remains suggests that humans were the ultimate cause of the extinction for some of the megafauna in Australia. They suggest that many of the extinctions had been staggered over the course of the late Middle Pleistocene and early Late Pleistocene, prior to human arrival, due to climatic stress. Others, including Steve Wroe, note that records in the Australian Pleistocene are rare, and there is not enough data to definitively determine the time of extinction of many of the species, with many of the species having no confirmed record within the last 100,000 years. Increased aridity during peak glaciation (about 18,000 years ago) may have also contributed, but most of the megafauna were already extinct by this time. Many modern researchers, including Tim Flannery, think that with the arrival of early Aboriginal Australians (around 70,000~65,000 years ago), hunting and the use of fire to manage their environment may have contributed to the extinction of the megafauna. ( June 2018) ( Learn how and when to remove this template message) Please do not remove this message until conditions to do so are met. Relevant discussion may be found on the talk page.
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