for National Geographic News
About 20,000 years ago, five human hunters sprinted across the soft clay on the edge of a wetland in what is now New South Wales, Australia.
Others also wandered across the muddy landscape, including a family of five, a small child, and a one-legged man who hopped without a crutch.
These early Aboriginal ancestors have long since vanished. But a record of their passage can be seen today in Mungo National Park, about 195 miles (315 kilometers) from Broken Hill (Australia map).
Woven among the sand dunes of the now arid Willandra Lakes World Heritage area are some 700 fossil footprints, 400 of them grouped in a set of 23 tracks (related photos: 2006 World Heritage sites named).
First spotted in 2003 by a young Mutthi Mutthi Aboriginal woman named Mary Pappen, Jr., the tracks are the oldest fossil human footprints ever found in Australia and the largest collection of such prints in the world.
Mary Pappen, Sr., a Mutthi Mutthi tribal elder and Pappen Jr.'s mother, says the age of the footprints highlights just how clever and adaptable Aboriginal ancestors were.
"We did not die 60,000 years ago. We didn't dry up and die away 26,000 years ago when the lakes were last full," she said.
"We are a people that nurtured and looked after our landscape and walked across it, and we are still here today."
(Read a travel column about seeing Australia through Aboriginal eyes.)
Steve Webb is a biological archaeologist with Bond University in Queensland. He has studied and partially excavated the tracks with help from other scientists and members of three area Aboriginal tribes.
Last December Webb published a study in the online edition of the Journal of Human Evolution describing eight of the tracks, and his work continues. Webb says the footprints reveal things that archaeological sites or skeletal remains couldn't.
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