Evidence of Indigenous occupation dating back 29,000 years has been uncovered along the River Murray in South Australia.
The find extends the known timeline of Aboriginal settlements in SA by as much as 22,000 years.
Researchers from Flinders University used radiocarbon dating to analyse river mussel shells, the remains of meals eaten long ago, from a site near Renmark, close to the Victorian border.
As well as finding evidence of the most ancient settlements, more than 30 additional radiocarbon dating results were collected in the region from the recent present to 15,000 years ago.
They also show how Aboriginal people adapted to an ever-changing river landscape.
During this extended period, climatic conditions were colder and drier across the Murray-Darling Basin.
In the SA Riverland, dunes were advancing into the Murray flood plains, river flows were unpredictable, and salt was accumulating in the valley.
"These studies show how our ancestors have lived over many thousands of years in the Riverland region," River Murray and Mallee Aboriginal Corporation spokeswoman Fiona Giles said
"How they managed to survive during times of hardship and plenty."
Study co-author Amy Roberts said the findings also filled in a significant gap in the understanding of Aboriginal occupation in the Murrray-Darling Basin.
Australian Associated Press