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Scientific American 60 Second Science. I'm Suzanne Bard.

Thousands of years ago in what's now the Kimberly region of Western Australia, Aboriginal artists created elaborate rock paintings.

Much of the artwork still exists today.

If you're walking beside the rivers and creeks and go up into the escarpments into rock shelters,

there are just thousands of rock art sites.

University of Melbourne Geocchronologist Damien Finch. The oldest paintings depict plants and animals.

But later works show human figures in ceremonial attire and ornate headdresses.

And then around the arms and the elbows and the knees, there's decorations, and sometimes I'll

be holding a clutch of boomerangs, and very often they're very finely executed using quite long

and elegant looking brush strokes.

The human centered paintings represent what's known as the Guianne style.

How old the artwork is has remained a mystery, however.

That's because the typical method for estimating the age of ancient objects, radiocarbon dating,

relies on the presence of organic carbon.

But the artists used ochre pigments that had no organic carbon.

There is nothing organic that we can apply carbon dating to. So the only thing that we can apply carbon dating to so the only thing that we can do is look

for stuff that's either been constructed on top of or underneath the paintings.

That's where mud wasps come in. The insects often incorporated organic matter into their

nests, which they built on the same rock faces where artists painted. The artists would

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