Footprints left on the sandy shore of a South African lagoon after a violent rainstorm 117,000 years ago, and amazingly preserved, have been identified as the oldest fossilized tracks of an anatomically modern human ever found.
The two prints, each measuring 8 1/2 inches in length--or about a 7 to 7 1/2 woman's shoe size--represent a rare discovery from the crucial but poorly understood period of history when modern humans first appeared, according to researchers who announced the discovery Thursday.
The smallish individual who ventured barefoot down the sandy incline that rainy day was a black African, probably a woman about 5 feet, 4 inches tall, who "looked just like us," the researchers said. She lived in roughly the same time and place as the hypothetical female known to paleoanthropologists as "Eve," the common genetic ancestor of every person alive today.
Although dating techniques show the prints to be ancient, Lee Berger, an American-born paleoanthropologist at the University of the Witwatersrand in Johannesburg, South Africa, said that the position of the toes, the distribution of weight and the well-developed arch are all so advanced that the prints "could have been made yesterday."
The tracks were discovered in September 1995 in what was once a steep sand dune, now hardened to gray sandstone, along Langebaan Lagoon, about 60 miles north of Cape Town. "Hundreds of people had walked over that area--including scientists--and not noticed the prints," Berger said.
Berger's colleague, David Roberts--a South African geologist from the Council for Geoscience--scrambled up and down the rock faces on a search for footprints after finding fossilized carnivore tracks and evidence of tool-making in ancient sedimentary rocks fringing the lagoon.
"On a hunch, I began searching for hominid footprints--and found them," Roberts said.
The work of Berger and Roberts is described in the September issue of National Geographic magazine.