Feb. 22 (UPI) -- Scientists have identified a life-size portrait of a kangaroo as Australia's oldest rock painting.
The ancient art, described Monday in the journal Nature Human Behavior, is between 17,500 and 17,100 years old.
Researchers dated the portrait, discovered in Western Australia's Kimberley region, by radiocarbon dating 27 mud wasp nests built under and over a collection of rock paintings.
"This is a significant find as through these initial estimates, we can understand something of the world these ancient artists lived in," lead study author Damien Finch said in a news release.
"We can never know what was in the mind of the artist when he/she painted this piece of work more than 600 generations ago, but we do know that the Naturalistic period extended back into the last ice age, so the environment was cooler and dryer than today," said Finch, a postdoctoral researcher at the University of Melbourne.
By studying differences in overlapping painting styles, scientists previously determined Australia's earliest rock paintings share similar aesthetics. Researchers dubbed the early phase Irregular Infill Animal or the Naturalistic period.
These early paintings often featured life-size animals, researchers say.
Scientists dated the kangaroo portrait as part of a larger effort to date Western Australia's rock art. Authors of the new paper said they were lucky to have found a painting with mud wasp nests built underneath and over top the artwork.
"We radiocarbon dated three wasp nests underlying the painting and three nests built over it to determine, confidently, that the painting is between 17,500 and 17,100 years old; most likely 17,300 years old," Finch said.
According to the new study, there are strong similarities between Australia's oldest rock painting and 40,000-year-old rock art from islands of Southeast Asia, suggesting a cultural link between the people of Southeast Asia and Western Australia's earliest indigenous populations.
"It's important that Indigenous knowledge and stories are not lost and continue to be shared for generations to come," said Cissy Gore-Birch, chair of the Balanggarra Aboriginal Corporation.
"The dating of this oldest known painting in an Australian rock shelter holds a great deal of significance for Aboriginal people and Australians and is an important part of Australia's history," Gore-Birch said.
By continuing to date mud wasp nests, scientists hope to produce a detailed historical timeline for Australia's many rock art styles.