August 14, 2008

Cemetary Discovery Suggests Ancient Sahara Was Green

Researchers have uncovered the remains of a woman and two children in an ancient cemetery located in what is now the Sahara Desert.

When they came across their skeletons, researchers found that the arms of the children were still extended to the woman in perpetual embrace in a cemetery that is providing an unprecedented view of how two civilizations lived there.

Paul Sereno of the University of Chicago and his colleagues came across the skeletons while searching for the remains of dinosaurs in the African country of Niger.

"Part of discovery is finding things that you least expect," Sereno said at a news conference Thursday at the National Geographic Society. "When you come across something like that in the middle of the desert it sends a tingle down your spine."

Among the remains of large fish and crocodiles, researchers came across about 200 graves of humans during fieldwork at the site in 2005 and 2006.

"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 ancient cemetery was discovered in a region called Gobero, hidden away in Niger's forbidding Tenere Desert, known to Tuareg nomads as a "desert within a desert." Researchers say there would have been a lake nearby at the time when people lived there.

The human remains dated from two distinct populations that lived there during wet times, with a dry period in between.

The researchers used radiocarbon dating to determine when these ancient people lived there. Even the most recent were some 1,000 years before the building of the pyramids in Egypt.

Researchers said the first group is known as the Kiffian. The colonized the region when the Sahara was at its wettest, between 10,000 and 8,000 years ago.

The Kiffians were hunters, and were tall people, sometimes reaching over 6 feet, researchers said.

The second group, known to researchers as the Tenerians, lived in the region between 7,000 and 4,500 years ago. The Tenerians were smaller and had a mixed economy of hunting, fishing and cattle herding.
Burials of the Tenerians were often adorned with jewelry. . For example, one girl had an upper-arm bracelet carved from a hippo tusk. An adult Tenerian male was buried with his skull resting on part of a clay vessel.

And pollen remains show the woman and two children were buried on a bed of flowers. The researchers preserved the group just as they had been for thousands of years.

"At first glance, it's hard to imagine two more biologically distinct groups of people burying their dead in the same place," said team member Chris Stojanowski, a bioarchaeologist from Arizona State University.

Stojanowski said ridges on the thigh bone of one Kiffian man show he had huge leg muscles, "which suggests he was eating a lot of protein and had an active, strenuous lifestyle. The Kiffian appear to have been fairly healthy - it would be difficult to grow a body that tall and muscular without sufficient nutrition."

On the other hand, ridges on a Tenerian male were barely visible. "This man's life was less rigorous, perhaps taking smaller fish and game with more advanced hunting technologies," Stojanowski said.

The finds are detailed in reports in Thursday's edition of the journal PLoS One and in the September issue of National Geographic Magazine.

The research was funded by National Geographic, the Island Fund of the New York Community Trust, the National Science Foundation and the Wenner-Gren Foundation for Anthropological Research.


Image Caption: BRACELET GIRL - Some 4800 years ago, this 11-year-old Tenerian girl was buried wearing an upper-arm bracelet carved from the tusk of a hippo, discovered by National Geographic Explorer-in-Residence Paul Sereno and his team. The Tenerian lived and buried their dead atop dunes near a lake in a region of the Sahara that was once greener that today. (Photo: Mike Hettwer, courtesy Project Exploration.)


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