The Naracoorte Caves have acted as natural pitfall traps for animals and sediment from mid-Pleistocene circa 500ka to the present. The caves contain a wealth of beautifully preserved dis-articulated skeletons of frogs, birds, reptiles and mammals, including most members of the extinct megafauna. High precision thermal ionisation mass spectrometry (TIMS) U/Th dating of intercalated flowstones has shown a distinct cyclicity in depositional events. Cave chambers with large openings tend to accumulate bones and sediment over several climatic cycles while those with smaller blockable entrances contain faunas restricted to shorter intervals. Notwithstanding differences in sample size there appears to be little faunal change over at least three glacial- interglacial cycles. Extinction is largely confined to browsers or grazer-browsers, while the extant forms outside their current range are largely species confined to sclerophyll forests with a dense understory and /or adjacent patches of grassland. Current research is focussed on narrowing the time interval for last appearance of megafuana in these deposits.