In a recently revealed study, our extinct ancestors, the Neanderthals, whose diets have been a topic of debate, were identified to have been carnivores.
The study, led by a French National Center for Scientific Research (CNRS) scholar, revealed through zinc isotope analysis that the food chain position of Neanderthals implies they were truly meat eaters.
Researchers in the new study published on October 17th in the journal Proceedings of the National Academy of Sciences (PNAS) examined the dental tartar of individuals from the Iberian Peninsula found at the Gabasa site in Spain.
Research brought to light that individual Neanderthals did not consume the blood of their prey but instead ate their bone marrow.
Previous studies revealed Neanderthals mainly consumed herbivores
Previous studies that examined the dental tartar of remains from the Iberian Peninsula show that Neanderthals mostly consumed herbivores and therefore relied primarily on nothing but a meat-heavy diet for sustenance.
Furthermore, perhaps due to nutritional stress, another study recorded evidence of cannibalism at two Iberian sites.
“I wanted to see how different their diets were from those of modern humans and how to explain it,” Klevia Jaouen, the lead author from CNRS, told reporters.
The research was equally relevant because several previous studies had attributed the disappearance of this species to their subsistence strategy or how they sourced food and other raw materials from their environment.
Previous techniques analyzed nitrogen isotopes in order to determine an individual’s position in the food chain, but scientists until now have generally had to extract proteins and analyze the nitrogen isotopes present in bone collagen.
However, the techniques can only be applied in temperate environments and only rarely on samples over fifty thousand years old.
Using nitrogen isotope analysis can be quite challenging or even impossible if favorable conditions are not met. This was the case for the molar from the Gabasa site analyzed in this study.
Zinc isotopes prove that Neanderthals were carnivores
According to the new study, with the use of a new technique applied to the Neanderthal individual from Gabasa, a zinc isotope signature was identified.
Due to the absence of cut marks on hominin and carnivore bones, researchers ruled out cannibalism in Neanderthals. Hominins are a group consisting of modern humans, extinct human species, and all our immediate ancestors.
A low zinc value suggests that the species ate muscle and liver from deer and rabbits, leaving out their blood and bones.
Hence, because of identified hindrances in previous methods, Jaouen and her colleagues decided to use zinc isotopes in the tooth enamel. Zinc is a mineral that is resistant to all forms of degradation.
The same methodology was also conducted on the bones of animals from the same time period and geographical area, including on carnivores such as lynxes and wolves and herbivores like rabbits and chamois.
Generated results after the experiment indicated that the Neanderthal to whom the tooth from the Gabasa site belonged was probably a carnivore who did not consume the blood of its prey.
Analysis of zinc isotope in Neanderthal’s tooth
In regards to all methodologies ever used in this kind of related research, it was the first time the method of analyzing zinc isotope ratios in Neanderthal tooth enamel to identify their diet was implemented.
The research team noted that the lower the proportions of zinc isotopes in the bones, the more likely they are to belong to a carnivore.
The remains of the bones found at the site indicate that this individual also consumed the bone marrow of its prey without actually consuming the bones. Analyses show that this Neanderthal likely died in the same place they had lived in as a child.
In comparison to other techniques, the new zinc isotope analysis method makes it easier to distinguish between omnivores and carnivores.
The scientists said that they will attempt to replicate the experiment on individuals from other centers such as the Payre site in southeastern France, where new research is underway to ascertain the results.