The term 'Sahara' depicts a vast desert region, yet it is a desert region of dramatic variation. And within the Sahara the numerous prehistoric rock art sites display an equally dramatic variation.

Take Niger; it is a country which incorporates both the Sahel (the ecoclimatic and biogeographic zone of transition in Africa between the Sahara Desert to the north and the Sudanian Savanna to the south) and the Sahara. Most of Niger's prehistoric rock art is located in the northern desert area in and around the Air Mountains, mainly consisting of rock engravings.

#prehistoric #RockArt sites in #Sahara display dramatic variation in style and age https://t.co/Nd0BnTtDTJ pic.twitter.com/9FVH0SHwME

— Bradshaw Foundation (@BradshawFND) March 22, 2016

At Anakom, there is a row of engraved giraffe (above) on a rock panel about 9 meters above the ground. The giraffe are of various sizes, and dominate the panel which also has other carvings that appear to be older, based on their style and the more eroded appearance.

The patterns on the giraffe - the defined patches on the coat, or pelt - show a consistency in execution, and along with the refined tapered legs, the general depiction of the giraffe is very stylised. This contrasts with other giraffe carvings in Niger, such as the Dabous giraffe (below) where, for example, the large polygonal spots of the coat and upper legs are depicted more realistically.

A third style can be found at another petroglyph site at Anakom (below), displaying what appears to be a mixture of heavy stylisation (note the accompanying ostriches) yet 'cruder', more hurried, execution.

All three styles display a deliberate carving technique - which may or may not be attributed to the work of a single artist in each case - but the artistic variation is unmistakable, and almost certainly point to spatial, temporal and ethnic differences.

Petroglyphs are notoriously hard to date, but based on style, this may make the carvings at Anakom more recent; the panel 9 meters above the ground are estimated to be 4,500 years old, whereas the Dabous giraffes are thought to be between 8,000 and 6,000 years old.

View more rock art in the African Rock Art Archive:

http://www.bradshawfoundation.com/africa/index.php