Debris on Neanderthal teeth rewrite our understanding of their diets
Your dentist may beg to differ, but there’s value in dirty teeth. That value may not be realized by you, or even the first person to find your tooth long after you’ve died, but ancient teeth have been found to carry excellent records of the ecology of ancient creatures. This may not apply to teeth millions of years old, but plaque built up on Neanderthal teeth from hundreds of thousands of years ago has changed our understanding of their diet, as well a how they interacted with the world around them.
Neanderthals (Homo neanderthalensis) were once assumed to have been largely carnivorous, hunting the large game that lived in the wood with them hundreds of thousands of years ago. Neanderthals bones with evidence of butchering even raised the idea that they were somewhat indiscriminate in their taste for meat, and that maybe this narrow diet helped lead to their eventual extinction. Eventually, scientists realized that Neanderthal teeth told a different story, and that the bits of plaque left on recovered teeth could provide rather direct evidence about what the were eating.
Plants in the plaque
Looking at the micro-fossils stuck to the side of Neanderthal teeth, scientists found that meat was a big part of the menu, but that a variety of plants made it into their mouths as well. Traces of grass, nuts and legumes were all found on dirty teeth, showing a fair amount of gathering to go along with the previously understood hunting. Teeth also showed traces of flowers and herbs like chamomile and yarrow, presumably for their medicinal purposes. Neanderthal’s had the genes necessary to be sensitive to bitter, potentially poisonous plants, so they were apparently selecting these plants quite specifically to cope with digestive problems or even tooth aches.
Fir tree floss
It might seem Neanderthals must have had pretty poor dental hygiene if this much can be found from what was stuck to their teeth. Instead, the reverse was true, as Neanderthal teeth seemed to be healthy and strong throughout their whole lives, even with a bit of plaque stuck to them. We don’t think this was due to some amazing toothpaste or Ice Age toothbrush, but bits of conifer twigs found in ancient skulls might have been from some diligent use of toothpicks, a habit other primates are known to partake in. Wood flakes aren’t as easy to explain as legume mush though, since it may have also been a case when Neanderthals were simply holding something in their mouth when their hands were full, or seeking conifer resin as an antibiotic. Whatever the purpose, all this dental debris certainly didn’t seem to cause extra tooth decay, so anthropologists are happy Neanderthals weren’t brushing and flossing twice a day.
Source: What Neanderthals' healthy teeth tell us about their minds by Melissa Hogenboom, BBC Earth