Stone Age graveyard reveals

The largest Stone Age graveyard found in the Sahara, which provides an unparalleled record of life when the region was green, has been discovered in Niger, an international team of archaeologists led by University of Chicago Professor Paul Sereno reported here on Thursday.
The remarkable archaeological site, dating back 10,000 years and called Gobero after the Tuareg name for the area, was brimming with skeletons of humans and animals -- including large fish and crocodiles. Gobero is hidden away within Niger's forbidding Tenere Desert.
The discovery of the lakeside graveyard -- representing two successive human populations divided by more than 1,000 years -- is reported in the Sept. issue of National Geographic magazine and the Aug. 14 issue of the journal PLoS ONE.
As they explored the site, the team tiptoed among dozens of fossilized human skeletons laid bare on the surface of an ancient dune field by the hot Saharan wind. Jawbones still clenched nearly full sets of teeth; a tiny hand reached up through the sand, its finger bones intact. On the surface lay harpoon points, potsherds, beads and stone tools. The site was pristine, apparently never visited.
"Everywhere you turned, there were bones belonging to animals that don't live in the desert," said Sereno. "I realized we were in the green Sahara."
The excavation eventually revealed some 200 graves clearly belonging to two successive lakeside populations. The older group, determined to be Kiffian, were hunters of wild game who left evidence that they also speared huge perch with harpoons when they colonized the green Sahara during its wettest period between 10,000 and 8,000 years ago. Their tall stature, sometimes reaching well over 1.8 meters, was not immediately apparent from their tightly bound burial positions.
The more recent population was the Tenerian, a more lightly built people who appeared to have had a diverse economy of hunting, fishing and cattle herding. They lived during the latter part of the green Sahara, about 7,000 to 4,500 years ago. Their one-of-a-kind burials often included jewelry or ritual poses -- a girl wearing an upper-arm bracelet carved from a hippo tusk, for example, and a stunning triple burial containing a woman and two children in a poignant embrace.
Although the Sahara has long been the world's largest desert, a faint wobble in Earth's orbit and other factors occurring some 12,000 years ago caused Africa's seasonal monsoons to shift slightly north, bringing new rains to the Sahara. From Egypt in the east to Mauritania in the west, lakes with lush margins dotted the formerly parched landscape, drawing animals, fish and eventually people. Separating these two populations was an arid interval perhaps as long as a millennium that began about 8,000 years ago, when the lake disappeared and the site was abandoned, said the archaeologists.
The team is continuing to analyze Gobero bones for more clues to the people's health and diet. A large-scale return expedition is planned to the site to further explore the two populations that coped with extreme climate change.