The Sima de los Huesos population had a varied diet

The population from Sima de los Huesos (Atapuerca Mountains, Burgos), one of Europe’s most important paleoanthropological assemblages, may not have followed a diet dominated exclusively by meat, as has often been assumed in scientific literature. A new study concludes that these hominins consumed a comparable combination of plant and animal resources, pointing to a more diverse diet than traditionally proposed.

This is the main conclusion of a paper recently published in the Journal of Human Evolution, led by the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), with the participation of IPHES-CERCA researcher Marina Lozano. The research reconstructed the dietary habits of this population through the analysis of dental macrowear, and also explored whether this wear reflects the environmental conditions of the glacial period known as MIS 12, one of the coldest globally, which occurred around 450,000 years ago.

The results not only provide new evidence about diet, but also offer relevant information about the environment in which these hominins lived, considered the closest relatives of Neanderthals. According to the study, the observed pattern would be consistent with an open woodland landscape and relatively more stable environmental conditions, in contrast to the classic picture of a particularly severe MIS 12, highly restrictive for plant resources.

A wear pattern incompatible with a hypercarnivorous diet

Beyond the morphological similarities between Sima de los Huesos individuals and Neanderthals, it has often been suggested that both groups shared similar dietary strategies, interpreting them as hypercarnivorous populations. Under this premise, one would expect a wear pattern comparable to that documented in human or animal communities that inhabited cold environments, where plant availability is lower and animal protein constitutes the main resource.

However, the analysis reveals a distinct dental wear pattern, compatible with a balanced intake of plant and animal resources, along with additional indications of a diet that was probably less abrasive than that of other groups used for comparison.

Digital analysis of dental macrowear using micro-CT

The study analysed a total of 16 upper molars, examined through micro-computed tomography (micro-CT). From these scans, three-dimensional models of each tooth were generated and, using specific software, the areas corresponding to wear facets—flat, polished surfaces produced by chewing—were identified, digitised and measured.

To contextualise the results, the team also included comparative samples of Neanderthals from different regions and chronologies, as well as modern hunter-gatherer groups, including Inuit populations from Alaska and Australian Aboriginal groups.

What wear reveals: diet, resource availability and ecology

Dental macrowear reflects long-term dietary adaptation, as it results from the specific mandibular movements required to process foods with different physical properties. In general, transverse jaw movements (associated with processing hard or abrasive plant foods) tend to produce a higher proportion of wear facets on the lingual side of upper molars. By contrast, a diet with a greater intake of meat is usually associated with more vertical chewing movements, with a higher proportion of wear in the buccal region.

In this way, wear patterns not only provide evidence of dietary preferences, but also of ecological conditions such as food availability in the environment. Different species or populations living in similar environments may show comparable patterns, whereas colder settings with more restricted diets often display distinct wear signatures.

In the case of Sima de los Huesos, the observed results point to a more varied diet, moving away from a strictly carnivorous model, contributing to a reassessment of traditional interpretations of these hominins within their environmental and evolutionary context.

Article reference

Martín-Francés, L., Martinón-Torres, M., Lozano, M., et al. Reconstructing dietary preferences in the Middle Pleistocene Sima de los Huesos population: A molar macrowear perspective. Journal of Human Evolution (2026).

https://doi.org/10.1016/j.jhevol.2025.103797