lion (Thylacoleo carnifex), the flightless bird Genyornis, the five-meter long snake Wonambi and the giant monitor lizard Megalania. Since 450 Ka, 88 Australian megafauna species have gone extinct. There are several hypotheses that attempt to explain why Pleistocene Australian megafauna went extinct. Most studies point to either climate change or human activity as reasons for the die off, but there is not yet a consensus among scientists about which factor had a larger impact. A scarcity of reliably dated megafaunal bone deposits has made it difficult to construct timelines for megafaunal extinctions in certain areas, leading to a divide among researches about when and how megafaunal species went extinct. Several studies provide evidence that climate change caused megafaunal extinction during the Pleistocene in Australia. One group of researchers analyzed fossilized teeth found at Cuddie Springs in southeastern Australia. By analyzing oxygen isotopes, they measured aridity, and by analyzing carbon isotopes and dental microwear texture analysis, they assessed megafaunal diets and vegetation. During the middle Pleistocene, southeastern Australia was dominated by browsers, including fauna that consumed C4 plants. By the late Pleistocene, the C4 plant dietary component had decreased considerably. This shift may have been caused by increasingly arid conditions, which may have caused dietary restrictions. Other isotopic analyses of eggshells and wombat teeth also point to a decline of C4 vegetation after 45 Ka. This decline in C4 vegetation is coincident with increasing aridity. Increasingly arid conditions in southeastern Australia during the late Pleistocene may have stressed megafauna, and contributed to their decline. Human activity may have caused Australian megafaunal extinction during the Pleistocene, although this idea is hotly debated. To determine whether humans caused an extinction, three criteria must be met: (1) if megafauna species went extinct before a significant climate event but after human colonization, researchers can infer that the extinction was probably caused by humans; (2) if climate change during the studied epoch was not more significant than climate change during previous epochs, then any extinctions during that time were probably not caused by climate change; and (3) if all or most megafauna was still extant when humans arrived, then it is possible that human activity caused the extinction. Some researchers believe that humans were probably not responsible for the megafaunal extinctions in Sahul. They contribute the extinctions to climate change, and argue that most megafaunal species do not appear in the fossil record within 95 Ka