We’ve long known that modern humans, or Homo sapiens, existed in Africa as far back as 200,000 years ago. Early humans in Australia were once thought to have arrived 47,000 years ago, signaling one of the later stops in the journey of human migration and one that would have required massive sea voyages.

A new discovery, recently published in the journal Nature, is challenging that, dating human arrival in Australia to 65,000 years ago, making Aboriginal Australian societies 18,000 years older than previously thought (although pending research on a rock shelter site could shift that downward closer to 10,000 years, if that pans out).

A team of archaeologists from the University of Queensland came to their conclusions by excavating a rock shelter in Majedbebe, a region in northern Australia, during digs conducted in 2012 and 2015. Among the artifacts found in the region were stone tools and hatchets, indicating an advanced understanding of weapon making. Similar hatches did not appear in other cultures for another 20,000 years, claimed the study’s authors.

"The axes were perfectly preserved, tucked up against the back wall of the shelter as we dug further and further," one of the study’s authors, Chris Clarkson, told Australia’s Fairfax Media.

Previous methods of dating artifacts relied on a technique called radiocarbon dating. However, the technique is only capable of providing accurate dates as far back as 45,000 years ago.

To reach their conclusion that humans arrived in Australia 65,000 years ago, the researchers used an additional technique called optically stimulated luminescence (OSL). The technique is applied to mineral grains and determines when it was last exposed to light, thus indicating to researchers how long an artifact has been buried.

The artifacts found by the archaeological team initially dated back only 10,000 years. As they dug further into the shelter, the found tools dating back 35,000, 40,000, and 65,000 years.

In order to reach Australia, Australia’s Aboriginal people would have had to undertake a nearly 60-mile voyage from surrounding regions. Clarkson also told the Sydney Morning Herald that it’s possible early Australians walked to the northern regions of the continent from Papau New Guinea when sea levels were significantly lower.

Chris Stringer, who wrote the book The Origin of Our Species and works as a researcher at the Natural History Museum in London, noted that human arrival in Australia marks a turning point in our evolution.

In an emailed statement to National Geographic, Stringer noted that the voyage necessary to arrive in Australia, “clearly demonstrates the high capabilities of the people who first accomplished it.”

Stringer also noted that pushing back the time period for human migration indicates that early humans may not have been in direct conflict with other hominids and animals to the extent previously thought. Earlier studies suggested human arrival in Australia corresponded with the extinction of multiple species. Human migration has also been attributed to the decline of Neanderthals.

To contextualize just how significant this 18,000-year extension is for understanding the history of Australia’s Aboriginal communities, the Sydney Morning Herald noted that, if Aboriginal culture was 24 hours old, white people have only been on the continent for five minutes.