Ancient human saunters into limelight.

About 117,000 years ago, a person no different anatomically from people living today strode down a sand dune toward a lagoon in southern Africa and made a few lasting impressions. A rainstorm had given the sand a mushy consistency that held three footprints intact; the wind then blew dry sand into the tracks and covered them with material that turned to rock and slowly eroded over tens of thousands of years.

In September 1995, South African geologist David Roberts of the Council for Geoscience in Bellville discovered those tracks, the oldest known footprints of any anatomically modern human. Roberts and Lee R. Berger, an anthropologist at the University of the Witwatersrand in Johannesburg, South Africa, announced the find last week at a press conference at the National Geographic Society in Washington, D.C.

"These footprints are living evidence of an ancient human adventure," Berger says. "They're another piece in a largely empty puzzle we have for human evolution in Africa between 500,000 and 60,000 years ago."

Found in rock along Langebaan Lagoon, about 60 miles north of Capetown, each of the footprints is 8 1/2 inches long. Comparisons with feet of modern South African hunter-gatherers place the ancient stroller at 5 feet to 5 feet 4 inches tall. Being relatively short, the person was probably female, Berger says.

Measurements of radioactive elements in surrounding rock yielded preliminary estimates of the footprints' age. These were narrowed down by consulting independent evidence regarding the timing of periods of global warmth and rising se levels around 100,000 years ago. The prints were made during one such period, Roberts holds.

The ancient tracks will not resolve the current debate over human origins (SN: 7/19/97, p. 37), but they do come from a group of ancient folks who exhibited sophisticated behaviors (SN: 4/12/97, p. 222).