The site now known as “Gobero” was first discovered during a 2000 paleontology expedition to Niger being led by Dr. Paul Sereno. The team was out cruising the desert in three Land Rovers at maximum distance from base camp at mid day, knowing that it was urgent that they head back toward camp for safety. Paul urged them on a half mile farther, promising he would turn back after surmounting a low ridge on the horizon. Just before turning back, team member Rudyard Sadlier, who was in Paul's vehicle, spotted some fossil bone. Paul stopped the caravan for a minute, and everyone began to find fossils scattered on the sandy desert floor within yards of the vehicles. But these dark brown fossils were than the dinosaur-age fossils they’d been tracking and collecting by the ton. They belonged to recent species. Rud's bone was an armor plate from a crocodile similar to today's Nile croc. Then another student, David Blackburn, announced with glee that he had just found a fragment from a human skull.
On the hood of one of the Land Rovers, the team assembled in a few minutes bones from a menagerie of animals that told of much wetter times than the hyper-arid parched landscape where they were found—crocs, hippos, fish, and humans. Expedition photographer, Mike Hettwer, had wandered a bit farther from the vehicles, but returned suddenly thrusting his digital camera at us. "That ain't nothing. Look at this. Whole human skeletons. Just over there, lots of them."
We knew instantly we could be standing on the edge of some remarkable archaeological site. Still, we were not fully prepared for what we would see, as we began to explore the low ancient dunes a short distance from the vehicles. Complete skeletons of humans and other vertebrates lay on the desert surface along with stone tools and pottery shards.
It would take another preliminary visit in 2003 and four expeditions (2005, 2006, 2011, 2012) and an international teams of paleontologists, archaeologists, geologists, cartographers, technicians and photographers to piece together the science and the story of the site that more than any other reveals life in the Green Sahara. Now sketched in the pages of National Geographic Magazine (Lost Tribes of the Green Sahara, September, 2008) and in a NGT/PBS Nova Special (Skeletons of the Sahara, September 25, 2013), the significance of the discovery of Gobero is revealed for all to see.
Many thanks to all team members, to associated research colleagues in several countries, to a dedicated lab staff, to expedition photographers and in particular Mike Hettwer, and to the National Geographic Society, National Science Foundation, Whitten-Newman Foundation, and especially to Elizabeth Meyer for their support of the expeditions and research. This project would not have been possible without the generosity and hospitality of the country of Niger, our Niger-ian colleagues and the people living in and around Agadez.
The GOBERO STORY
In 2000 a major archaeological discovery made by a team led by paleontologist Paul Sereno opened a window onto the “Green Sahara,” a moment of time that spanned 10,000 to 5,000 years ago.
Called Gobero after the local Tuareg name for the area, the discovery revealed a suite of closely-spaced archaeological sites preserved in two kinds of settings—paleodune and paleolake deposits. These sites document a 5000-year-long drama of changing climate and changing cultures.
During a dry period ancient dunes accumulated 16,000 to 9700 years ago. When the climate became considerably more humid, depressions between the dunes filled with fresh water and formed lakes. Humans rapidly colonized the “greened” desert; they found Gobero a particularly attractive locale for thousands of years.
WHY WAS GOBERO SO GREEN?
Geology holds part of the answer: a fault in the dinosaur-age sandstone in the Gobero area forms a long, low ridge. Rain water draining from the nearby Aïr Mountains pooled against the fault ridge to form a freshwater lake which stretched about 3 km (2 miles) in diameter. Dunes extended into the middle of the lake and provided prime beachfront real estate.
Kiffian people first settled in the Gobero area about 9700 years ago. These people lived on the upper layer of a dune and established a cemetery there. Kiffian refuse piles (middens) and scores of their burials are preserved.
The nearby lake could support a sizeable human population: it teemed with fish and crocodiles and served as a watering hole for a wide variety of animals. From their burials, we know that Kiffians were a tall, robust-boned people. They hunted with spears tipped with tiny bladelets (called microliths) and fished with harpoons carved from bone. They decorated their pottery with characteristic parallel wavy lines.
Starting around 8000 years ago, desert conditions returned. Extreme heat and drought drove people from the area and the lake dried up.
Visit the Kiffian image gallery
Then, around 7000 years ago, the climate improved and the lake filled again. People returned to the area and once again lived on the dune and buried their dead in the cemetery. These Tenerean people were noticeably shorter in stature and lighter in build.
Although their middens are filled with clams, small fish and antelope bones, rare cow bones indicate these people knew how to tend domesticated livestock.
They hunted with bows and arrows, often adorned themselves with necklaces and bracelets of eggshell and ivory, and stamped their pottery with pitted or zigzag patterns.
Visit the Tenerean photo gallery
THE END OF THE ERA
By about 4500 years ago, the climate began its slow deterioration to present day arid conditions. Humans no longer lived permanently at Gobero but rather migrated through the area with livestock, sometimes leaving a hearth or discarding their undecorated pottery.
The archaeological record at Gobero came to a close; the era of the “green” Sahara and its distinct cultures, preserved only in ancient dunes and dried lake bottoms.