Finds at a rock shelter in Kakadu National Park suggest that humans have been living in Australia for least 65,000 years, and possibly even up to 80,000 years—far longer than previously thought. The findings also suggested that people crossed over from southeast Asia at a time when sea levels were lower than they are today, creating a "land bridge". The date also means that Aboriginal people roamed Australia at the same time as some giant marsupials, such as Diprotodon and the marsupial lion, which are now extinct. The discoveries indicate that these animals lived alongside humans for thousands of years: they were not quickly wiped out by over-hunting, as has sometimes been proposed.

The research was carried out at the Madjedbebe rock shelter on the western edge of the Arnhem Land plateau in Australia's Northern Territory by a team of archaeologists led by Associate Professor Chris Clarkson, from The University of Queensland School of Social Science. The team worked in partnership with the Aboriginal Australian traditional owners, the Mirarr, who retained total control over the dig and all the objects found. The site was first excavated in the 1970s.

The team uncovered more than 10,000 artefacts (objects made by people) buried in 2.6 metres of sand and sediment at the site, including stone axes, seed-grinding tools and finely carved stone points used for spear tips. They also found large quantities of ground ochre, a powdered mineral used as pigments for paints—region known for its spectacular rock art by the Aboriginal Australians. In the very deepest levels of sediment, some artefacts were radiocarbon dated at around 80,000 years old.