An international team of researchers has found new evidence that our prehistoric ancestors had a detailed understanding of plants long before the development of agriculture. By extracting chemical compounds and microfossils from dental calculus (calcified dental plaque) from ancient teeth, the researchers were able to provide an entirely new perspective on our ancestors' diets. Their research suggests that purple nut sedge (Cyperus rotundus) -- today regarded as a nuisance weed -- formed an important part of the prehistoric diet.

Source: Tooth plaque provides unique insights into our prehistoric ancestors' diet