The kangaroo image was among a number of rock paintings first recorded by researchers in the 1990s in the Kimberley region, which has one of the world’s largest collections of indigenous petroglyphs. Scientists from various universities and research firms worked with local Indigenous leaders to analyze the paintings, and their findings were published Monday in the journal Nature Human Behavior.
They found the remains of 27 ancient mud wasp nests – which can be dated on radiocarbon – above and below 16 different rock paintings, the paper said.
The strategy is simple: if the nests are built on top of the petroglyphs, the art must be older. If the art is built on nests, the nests must be older. Dating these nests thus gives scientists a minimum and maximum age for the rock paintings.
The old nests also often contain plant material or fragments of insects that parent wasps collected for larvae to feed on, all of which contain carbon.
By dating the wasp nests, the authors of this study determined that most of the paintings were made between 17,000 and 13,000 years ago. Some of the oldest paintings include a picture of a boomerang and a rare depiction of a human figure lying on their back. Others depicted animals, including a snake, a lizard-like figure, and three macropods – the marsupial family that includes kangaroos, wallabies, and quokkas.
The kangaroo painting was dated to between 17,100 and 17,500 years ago. It is painted on the sloping ceiling of a rock shelter that is home to thousands of petrified mud wasp nests.
“Much more data from this period is needed before the full chronological size of the paintings that are still visible can be determined,” the researchers wrote.