In 1943 clay shards were discovered during tin mining operations on the southern and western slopes of the Jos Plateau. When reconstructed they were found to be representations of human heads and animals. At the time no archaeologists were present in the region and reconstruction work was carried out by art historians. The disturbance caused by the mining operations meant that the finds could not be dated with any accuracy.
Similar discoveries have been made across a large region of the plateau, stretching 500 km east to west and 300 km north to south. Both the terracotta sculptures and the society which made them are known by the name of the village near to which the first discovery was made: Nok.
Since 1943 archaeological studies, especially at two important sites at Taruga and Samun Dukiya, have provided more accurate information. The pottery has been dated, mainly by thermo-luminescence testing and radio-carbon dating, to a period from 500 BCE to 200 CE. In addition to the Nok terracotta sculptures, domestic pottery, stone axes and other tools, and iron implements have been discovered. The Nok Culture spanned the end of the Neolithic (Stone Age) and start of the Iron Age in sub-Saharan Africa.
Archaeological evidence at the two sites suggest that these were permanent settlements, and centres for farming and manufacturing - this is the oldest evidence for an organised society in sub-Saharan Africa.
Iron working, smelting and fabrication of iron tools became widespread in the region form around 350 BCE. Archaeologists disagree whether this was an independent development (methods of smelting may have derived form the use of kilns for firing terracotta) or whether the skill was brought south form the North African coast by traders (records suggest that Phoenician traders were crossing (what is now) the Sahara at that time.
Nok culture terracottas are heralded as the prime evidence of pre-colonial civilization in sub-Saharan Africa, and it is suggested that the society eventually evolved into the later Yoruba kingdom of Ife. Later brass and terracotta sculptures of the Ife and Benin cultures show significant similarities with those found at Nok.