Australian archaeologists have found the world’s oldest known axe fragment.

In the remote Kimberley region of Western Australia, local experts uncovered an axe fragment about which was last used  45,000 to 49,000 years ago.

The Stone Age era it hails matches conservative estimates of the time humans arrived on the Australian continent.

It is about 10,000 years older than any previous ground-edge axe discoveries.

The experts say it is the latest piece of evidence to show the highly-advanced nature of Australia’s first inhabitants.

At a time when many human populations were living much more like their primate ancestors, the populations that became the first Australians were using tools, language and navigational skills that allowed them to travel the world.

“Since there are no known axes in Southeast Asia during the Ice Age, this discovery shows us that when humans arrived in Australia they began to experiment with new technologies, inventing ways to exploit the resources they encountered in the new Australian landscape,” University of Sydney researcher Professor Peter Hiscock said.

 “Polished stone axes were crucial tools in hunter-gatherer societies and were once the defining characteristic of the Neolithic phase of human life. But when were axes invented? This question has been pursued for decades, since archaeologists discovered that in Australia axes were older than in many other places. Now we have a discovery that appears to answer the question.”

The axe fragment was initially excavated in the early 1990s among food scraps, tools, artwork and other artifacts from Carpenter’s Gap; a large rock shelter known to be one of the first sites occupied by modern humans.

In 2014, further studies revealed a small fragment of a polished axe, recovered from the oldest levels of the site.

Their analysis has now revealed that it comes from an axe that had been shaped from basalt then polished by grinding it on another rock until it was very smooth.

The fragment came from the polished edge when it was later resharpened. The team believes the axe was most likely carried away to be used elsewhere, leaving the fragment behind.

“Nowhere else in the world do you get axes at this date. In Japan such axes appear about 35,000 years ago. But in most countries in the world they arrive with agriculture after 10,000 years ago,” said Professor Sue O’Connor, who made the initial find in the 1990s.

“We know that they didn’t have axes where they came from. There are no axes in the islands to our north. They arrived in Australia and innovated axes,” she said.

“Australian stone artefacts have often been characterised as being simple. But clearly that’s not the case when you have these hafted axes [axes with handles attached] earlier in Australia than anywhere else in the world.”

Professor Hiscock said the ground-edge axe technology specifically arose as the dispersing humans adapted to their new regional landscapes.

“Although humans spread across Australia, axe technology did not spread with them,” he said.

“Axes were only made in the tropical north, perhaps suggesting two different colonising groups or that the technology was abandoned as people spread into desert and subtopical woodlands.

“These differences between northern Australia, where axes were always used, and southern Australia, where they were not, originated around the time of colonisation and persisted until the last few thousand years when axes began to be made in most southern parts of mainland Australia.”

The discoveries will be published in this month’s issue of the journal Australian Archaeology.