These animals have been termed the Pleistocene megafauna. The woolly rhinoceros was a member of the Pleistocene megafauna. This adaptation allowed it to prey and scavenge on Pleistocene megafauna. There are similarities between prehistoric Australian megafauna and some mythical creatures from the Aboriginal dreamtime. For instance, there are ambiguities around the timing of sudden extinctions of Australian megafauna. The first people arrived in Florida before the extinction of the Pleistocene megafauna. Evidence suggests human hunting contributed to the extinction of the American megafauna. The close of the Cretaceous period saw the demise of the Mesozoic era reptilian megafauna. This could have been a major contributor to why the arctic megafauna went extinct. At least 37 genera of mammals were eliminated, including most of the megafauna. Other notable megafauna include the basking sharks. Paleoindians were hunter-gathers that roamed in bands and frequently hunted megafauna. It has been suggested that the African megafauna survived because they evolved alongside humans. Other animals including megafauna migrated in both directions. Some argue that natural climate change killed the megafauna.