The Nok of Nigeria

Rupp agrees. “When you look at a piece like this,” she says, referring to the just-discovered arm, “you can see that the Nok were experts at making terracotta. There was a specialized, creative class.” There may have been a kind of terracotta “guild,” which, if true, would suggest the Nok had well-developed class hierarchy, she adds.

Breunig and Rupp have found about 20 iron implements, including fearsome spear points, bracelets, and small knives, most of which are fairly crude-looking. How and when Africans developed iron is important because metallurgy is considered a crucial marker in the shift to complex societies. Manufacturing metal means better tools for farming, hunting, and preparing food, as well as better weapons for waging war and gaining resources. Yet whether metal-working creates the conditions for civilization to flourish or vice versa remains an open question for archaeologists.

Carbon dating on charcoal that Breunig gathered from a Nok iron smelter at a site called Intini yielded a date of between 519 and 410 B.C., suggesting that iron technology was established earlier than previous scholars, including Fagg, had realized. These may not be the oldest smelters in sub-Saharan Africa, however. French archaeologists have located evidence of iron-smelting in the Termit Hills of Niger from as early as 1400 B.C., but critics point out that the wood used for dating could have been centuries old, a problem that dogs carbon dating, especially in very arid places such as Niger, where the wood desiccates and lasts longer. Breunig acknowledges that the problem could distort dates for the Intini furnace as well. But he has an important piece of evidence—Nok pottery, found inside the furnace alongside the charcoal, suggesting that they were placed there around the same time.

As a result of his research, Breunig has been able to isolate a moment in time when iron and stone implements coexisted. Excavators regularly find iron tools only a short distance from Nok stone axes, suggesting they were used in the same communities, maybe even the same households. “When iron first develops, it might be too rare or too costly to be wasted on axes or other things that you can make with stone,” he says. “Our hypothesis is that iron tools replaced stone tools only after the technology was developed enough to deliver sufficient quantities of iron. The Nok is an almost perfect culture on which to test this assumption.”