A dinosaur-hunting expedition in the hyperarid southern Saharan desert known as Tenere revealed traces of early Holocene human occupants that date back to almost 8,000 B.C.E. The two hundred human burial sites discovered on the edge of a paleo-lake in Niger indicate extraordinary details about the history of humans.

The burial sites are among the earliest recorded cemeteries in Sahara, and expose fluctuations in the degree of habitability in this part of the Sahara Desert. The radiocarbon dates on various human remains found on site indicate two occupational phases, which appear to correspond to the humid periods in the regional climate.

The oldest cemetery dates back to approximately 7500 B.C.E., when the early inhabitants of the site discovered in sourthern Sahara , called Gobero, lived in very different conditions than what we see today in the region. The climate offered humid conditions, influencing the occupants’ style of life. The early Holocen population here is believed to have been a mostly sedentary one, with hunting, fishing, gathering as main occupations.

The study of the remains indicates a skeletally robust, trans-Saharan assemblage of Late Pleistocene to mid-Holocene human populations from the Maghreb and southern Sahara.

The arid interval in Late Pleistocen – early Holocene indicates weakened monsoons and aridification spread across Northern Africa. The deflated Ounanian artifacts discovered here, as well as the lack of a burial record, point to passing populations.

The wet conditions around 7700 B.C.E. begin to attract populations who settle here, also leaving funerary traces. The early occupants at Gobero began to abandon the area once the arid conditions started to set in, around 6,200 B.C.E. These harsh conditions, which apparently lasted for 1,000 years, have kept the human populations away from Gobero until mid-Holocene, when they returned.

Between 5200 – 2500 B.C.E., the Gobero occupants established the basis of a diversified subsistence economy, based on clams, fish, animals from the savannah, as well as some cattle husbandry. The occupational interval will now last for approximately two millenniums, after which the aridification period begins to spread once more and the permanent presence of humans in this part of the Sahara turns into a nomadic one.

The remains detain back to this period suggest more gracile skeletons, with shorter stature for both males and females, with long, high and narrow crania, as well as considerably longer faces. Their burial sites reveal semi-flexed postures on the left or right sides, and also include bones or tusks from local fauna, ceramics, lithic projectile points, as well as bone, ivory and shell ornaments.

Human occupation in the Tenere Desert has been, like in many other arid areas, influenced by humid periods which attracted human settlers.

“The Gobero site complex, which includes as many as 200 burials, underscore the scale and complexity of human occupation in a “greener” Sahara, as well as the fragility of that record under present conditions,” the study says.

The excavation site at Gobero was discovered in 2000, and revisited in 2003. In 2005 and 2006, scientists excavated 67 burials, while a minimum of 182 human burials are still preserved in central part of the Gobero site complex.

The study appears in the online journal PLoS ONE, and is co-authored by scientists at several universities and museums across the United States, Europe and Africa.