The problem with ancient Mesopotamia is that it keeps its bones quiet. The region that gave us writing, cities, and the first bureaucratic record-keeping has, for decades, resisted one of the most fundamental questions bioarchaeologists ask: what did people actually eat? Not the elites documented in ration tablets. Not the temple workers whose grain allocations fill administrative archives. The ordinary people. The ones buried without gold, without monuments, without the administrative attention that generates text.
At the third-millennium BCE site of Abu Tbeirah in southern Iraq, a medium-sized city situated about 30 kilometers from the ancient Persian Gulf shoreline and near the more famous urban center of Ur, researchers tried for years to extract collagen from human bone. Collagen is the workhorse of isotopic dietary reconstruction. When it survives, you can read nitrogen and carbon ratios directly and reconstruct trophic position with reasonable confidence. At Abu Tbeirah, only 3 of 48 samples tested in previous work yielded anything usable. The rest had been destroyed by the combination of heat, soil salinity, and widespread bitumen contamination that characterizes the southern Mesopotamian burial environment. The chemical record, for most purposes, was simply gone.
A team led by Matteo Giaccari of Sapienza University of Rome took a different approach.1 Rather than chasing collagen, they turned to zinc isotopes preserved in dental enamel.
