The seven nearby sites include an extensive cemetery and represent one of the largest and best preserved concentrations of ancient skeletons and artifacts ever found in the region, researchers say.
Some back ground from the expedition website:
"...the desert has waxed and waned since the last Ice Sge to eventually become the expanding desert we know today."
As the lakes evaporated and disappeared 6,000 years ago, the people that had based their livelihood on its aquatic life, the Kiffians, were replaced by the first pastoralists of the Sahara, the Tenereans. This next group of people tended herds of just-domesticated African cattle on the grasslands between the encroaching dunes. These cattle herders, the Tenereans, lived from about 5,500 to 3,500 years ago. Our site contains their tools and ceramics, including beautifully made green stone disk-shaped axes. All of these transitions were happening before the first pyramid in Egypt was ever constructed.
Again from National Geographic:
The site may not have been continuously occupied. But it was likely inhabited for much of that time, which was a crucial one in early human history.
During the New Stone Age, humans moved from hunter/gatherer societies to become early agrarians who domesticated plants and animals.
Tools such as large pottery and heavy grinding stones suggest that Kiffian peoples may have occupied the ancient lakeside area at least semi-permanently, Garcea says.
Scientists know that by about 6,300 years ago the Sahara's first pastoral people, the Tenereans, began tending herds of newly domesticated cattle.
And while the expedition team found remains of domestic cows and asses, researchers are uncertain whether Tenerean peoples occupied the particular dig site.
The team says the site's human remains were most striking. Members found hundreds of skeletons in the site's large cemetery, some still adorned with ancient jewelry.
The researchers found tools, such as precision stone blades, bone hooks, pottery stamps, and other artifacts, in graves and other site locations.
Some artifacts suggest travel and perhaps even distant trade. Stone tools made of pale green volcanic rock could have their source some 50 miles (80 kilometers) distant in the Air Mountains, an area rich with period rock art.
Unfortunately, the site has attracted looters:
But archaeologists are not the only ones who have visited the historic site. Niger is a poor nation, and the temptation to profit from its rich cultural history has proven too great for some.
"We followed some 4x4 tracks that our guides said were definitely not made by tourists but by vendors going out there for stolen artifacts," Sereno said. "A photographer with our team estimates that he photographed as many as 3,000 artifacts in one day, found in shops of communities near the site."
Worse yet, because the site is in the desert it suffers from deflation, or erosion caused by the wind, and is changing rapidly:
"The wind is destroying these sites very quickly," Garcea, the Italian archaeologist, said. "I saw pictures that [Sereno] took in 2003, and you can really see the deflation."
"Some skeletons that were covered are now exposed to the surface and the hyper-arid desert conditions. In two or three years I'm sure I won't be able to see some of the things that we can study now," she added.