The Nok Civilization.
"…The Nok Culture civilization was discovered in 1928. The first discoveries was accidentally unearthed at a level of 24 feet in an alluvial tin mine in the vicinity of the village of Nok in Jaba Local Government in the southern part of Kaduna state, near the Jos Plateau region which lies in the central part of Nigeria in west Africa . As a result of natural erosion and deposition, Nok terracottas were scattered at various depths throughout the Sahel grasslands, causing difficulty in the dating and classification of the mysterious artifacts.
Luckily, two archaeological sites, Samun Dukiya and Taruga, were found containing Nok art that had remained unmoved. Radiocarbon and thermo-luminescence tests narrowed the sculptures’ age down to between 2000 and 2500 years ago, making them some of the oldest in West Africa.
Because of the similarities between the two sites, archaeologist Graham Connah believes that “Nok artwork represents a style that was adopted by a range of iron-using farming societies of varying cultures, disputing the claim of solely being the diagnostic feature of Nok people.It is however a statement of fact that ,the Nok Terracotta fugurines earned it’s name due to the Nok civilization that inhabited the area from around 500 BC in the village of Nok in Jaba Local Government in the southern part of Kaduna state, which lies in the central part of Nigeria in west Africa . The Nok culture was considered to be the earliest sub-Saharan producer of life-sized Terracotta. The refinement of this culture is attested to by the image of a Nok dignitary figurine. Most parts of the terracotta is preserved in the form of scattered fragments. That is why Nok art is well known today only for the heads, both male and female, whose hairstyles are particularly detailed and refined. The statues are in fragments because the discoveries are usually made from alluvial mud, in terrain made by the erosion of water. The terracotta statues found there are hidden, rolled, polished, and broken. Rarely are works of great size conserved intact making them highly valued on the international art market. The terracotta figures are hollow, coil built, nearly life sized human heads and bodies that are depicted with highly stylized features, abundant jewellery, and varied postures….” http://nokculture.com/