Neanderthals are commonly seen as ferocious carnivores, but a study of their dental plaque has found they were adaptable, changing their diet to suit local conditions. In what is now modern-day Belgium, this did indeed mean a dinner of woolly rhinoceros, but on the Iberian Peninsular, they chose a meal of mushrooms. More surprisingly, it seems they had a knowledge of herbal medicine we have only recently matched.

These findings come from a ground-breaking study led by Dr Laura Weyrich of Adelaide University, who found DNA in the hard plaque known as calculus on fossilized Neanderthal jaws. Weyrich was able to distinguish DNA from the meals of five Neanderthals from different parts of Europe.

Two specimens, found near Spy, Belgium, had DNA from woolly rhinos and wild sheep in their teeth, Weyrich reports in Nature. Two from El Sidrón, Spain, on the other hand, had been eating pine nuts, moss, and mushrooms. Weyrich told IFLScience the area around El Sidrón was then heavily forested, and unlikely to support many large grazing animals, so it is not surprising the inhabitants ate a largely vegetarian diet.

The study also found DNA from mouth bacteria, which had more in common with that from a modern chimpanzee than yours or mine. Weyrich attributes this not just to the changes wrought on our mouths by toothbrushes and paste, but the influence of centuries of agriculture.

One of the Spanish Neanderthals was apparently sick. The combination of a dental abscess and an unpleasant stomach bug would have made life very uncomfortable, but it seems the tribe had some good ideas on what to do. The sick individual was consuming both poplar bark and grass with Penicillium mold on it. Poplar bark contains aspirin, while Penicillium is the original source of penicillin. 

Weyrich told IFLScience that a lot of the grasses the Neanderthals ate probably had mold on them and they may not have known what cured them, only that certain foods made them feel better when sick. Nevertheless, she is not aware of any other cases of humans seeking out Penicillium before Alexander Fleming's lucky find. Neanderthals possibly beat humans to one of the greatest scientific discoveries by at least 48,000 years.

No one has yet used dental plaque to conduct a similar analysis of the eating habits of our more direct ancestors. Weyrich said we don't know if the DNA extracted came from the last meal the Neanderthals ate before they died, or were an earlier selection that happened to get stuck in their teeth. Nevertheless, the findings fit well with previous attempts to establish Neanderthal diets based on the isotopes in their bones ways in which their teeth wore down. 

 ^{This cartoon of El Sidron Neandertals shows food items detected in their dental plaque in this study. Abel Grau/ Comunicación CSIC}