You can find out a lot about Neanderthals in the plaque on their teeth, apparently, and researchers hae determined in a new study a couple of interesting things: one is that their diets were very different depending on the individual, and another is that they made out with their human cousins. Scientists studied bits of food and microbes in the mouths of Neanderthals, which is easy to do since they obviously never went to the dentist and thus it makes for an interesting portal into their daily lives.

And scientists have lots of Neanderthal teeth in the fossil record to examine, with complete jaws of teeth in some cases. Keith Dobney, an archaeologist at the University of Liverpool, and colleagues looked at plaque and tartar from Neanderthals living in Europe about 50,000 years ago, and found a surprisingly varied diet depending on the individual.

One individual from Belgium appeared to eat mostly meat, which jives with what scientists generally understood about Neanderthals. But what surprised them is to find that Neanderthals in Spain that were examined ate no meat at all, preferring pine nuts, mushrooms and moss to meat.

But another possibly even more fascinating discovery hints at the relationship between Neanderthals and humans: scientists found that they shared some of the microbes of humans in their mouths, indicating that they were kissing, or at the very least food sharing. It suggests a much more intimate relationship than scientists imagined between the two groups.

“Dental plaque traps microorganisms that lived in the mouth and pathogens found in the respiratory and gastrointestinal tract, as well as bits of food stuck in the teeth – preserving the DNA for thousands of years,” said lead author Dr Laura Weyrich, from the University of Adelaide’s Australian Centre for Ancient DNA (ACAD) and Dental School.

“Genetic analysis of that DNA ‘locked-up’ in plaque, represents a unique window into Neandertal lifestyle – revealing new details of what they ate, what their health was like and how the environment impacted their behaviour.”

“We found that the Neandertals from Spy Cave consumed woolly rhinoceros and European wild sheep, supplemented with wild mushrooms. Those from El Sidrón Cave on the other hand showed no evidence for meat consumption, but appeared instead to have a largely vegetarian diet, comprising pine nuts, moss, mushrooms and tree bark – showing quite different lifestyles between the two groups” said Professor Alan Cooper, Director of ACAD..”