What was the Neanderthal diet? To answer that question, the researchers took a closer look at a Neanderthal molar.
Dentists are not happy about it at all, but archaeologists are all the more: dental plaque. The deposits on the teeth can provide valuable information about what a person used to eat. Archaeologists at the Center National de la Recherche Scientifique in Paris were pleasantly surprised to find plaque on the molar of a Neanderthal who lived in Gabasa, Spain, 143,000 years ago. New analytical techniques reveal that this person was a carnivore.
Plaque shaved off
Although plaque has previously been found on Neanderthal teeth, it was usually shaved off to study tooth growth and wear. But for research into the diet of the Neanderthals, the plate proved to be very valuable.
In 2017, for example, researchers discovered a remarkable amount of plant DNA on the teeth of another Spanish Neanderthal. It indicated that this Neanderthal ate a lot of plant food. This is in contrast to its Belgian counterparts, whose dental plaque contained a lot of DNA from woolly rhinos and wild sheep. The Neanderthal, whose molar has now been analysed, lived in Gabasa, south of the Pyrenees.
To determine a hominin’s position in the food chain, researchers usually isolate collagen from the bones. That nitrogen isotopes are then analyzed. From this it can be deduced what he ate. The disadvantage of this method is that it can rarely be used on samples over 50,000 years old. Collagen breaks down over time, depending on the climate.
So the researchers chose a different method than Gabasa: the analysis of zinc isotopes. It is now the first time that this method of analysis has been applied to the diet of a Neanderthal. Zinc is one mineral that does not break down. The lower the black contentThe zinc isotope in the dental plaque, the more likely it is that the individual was actually a carnivore. This is because the animal body stores the lighter isotope better and excretes the heavy one – over time, the proportion of the heavy isotope in the total zinc decreases. A mammal that eats a lot of meat also gets less of the heavy isotope in its diet because it eats animals that in turn have stored less of it.
The researchers performed the same analysis on the bones of animals that lived in the same period and in the same area as the owner of the molar. Think of carnivores such as lynx and wolves, but also herbivores such as rabbits and chamois. The results showed that the Neanderthal from Gabasa actually only ate meat.
Broken bones at the site of the molar further showed that it also consumed the bone marrow of its prey. Moreover, he most likely died in the same place where he spent his childhood.
According to the researchers, the new method makes it easier to distinguish between herbivores, omnivores and carnivores. To further confirm their findings, they will now repeat their experiment on molars of hominids from other places in Europe.
“We already assumed that Neanderthals had a very meat-rich diet,” says paleontologist Lars van den Hoek Ostende from the Naturalis Biodiversity Center. “We know this from research into nitrogen isotopes. But the importance of this study lies not so much in the results, but in the new method that has been used.”
Evolutionary biologist Nico van Straalen from VU Amsterdam is also satisfied with the zinc isotope analysis. “It seems like a feat. Zinc itself is already a trace element, so the rare isotopes of zinc are present in even lower concentrations.”
Nevertheless, Van den Hoek Ostend still has some critical notes. “The only Neanderthal zinc measurement that was included shows a value that deviates far from what you would expect from a carnivore. And the lynx, a true carnivore, has the highest zinc value. The method therefore needs to be polished a little. It actually seems like a good idea to study other Neanderthals to see if they also provide such a different value compared to the other fauna. If so, then we can really make assumptions about their diet.”
Sources: PNAS, CNRS via EurekAlert!