An archaeologist found what is believed to be the oldest rock art in Australia and one of the oldest in the world -- a 28,000-year-old work created in a cave in the outback by an Aboriginal.

Bryce Barker, an archaeologist with the University of Southern Queensland, told the Associated Press that the discovery of Australia's oldest rock art, made with charcoal, was found in June 2011, and radiocarbon dating on the rock art was completed just recently.

It's the oldest unequivocally dated rock art in Australia, Barker told the AP. The rock art, which can be seen here, is also one of the oldest in the world.

The Australian cave where the discovery was made may have been occupied for 45,000 years, according to Barker's estimations. The cave is part of a rock shelter known as Narwala Gabarnmang, about 90 miles from the Australian outback town of Katherine, according to discovery.com.

Since the oldest rock art in Australia was made with charcoal, radiocarbon dating was able to be used on the discovery. Most rock art is made with mineral paint, which makes the works poor candidates for radiocarbon dating.

One of the things that makes this little fragment of art unique is that it is drawn in charcoal ... which means we could directly date it, Barker said, according to discovery.com.

Sally May, an archaeologist at Australian National University, said Barker's discovery is not unexpected, although she did call the find incredibly significant.

I don't think it will surprise anyone that rock art is that old in Australia because we know people have been here a lot longer than that and there's no reason to believe they weren't producing art, May told the AP.

Barker said he is certain that older rock art will eventually be found in Australia because of the long history of Aboriginals.

[W]e're convinced that we'll find older and the reason is that the site this comes from, we know that Aboriginal people started using this site 45,000 years ago, he said, according to discovery.com.  We've only excavated a tiny fraction of the site and we expect there will be art older than 28,000 years in the site.

The oldest rock art found in Australia is about 13,000 years younger than the oldest discovered rock art in the world.

The oldest, found in Spain's El Castillo cave, is 48,000 years old -- paint blown onto a cave wall using hand stencils and red disks, according to the AP. Uranium-thorium dating was used to date the rock art.