Research shows Neanderthals gathered shellfish like modern humans

By Stephen Beech

Cavemen gathered shellfish to eat using the same methods as modern humans, according to new research.

Neanderthals in southern Europe collected mollusks throughout the year — with a marked preference for the colder months, suggests the study.

The research, published in the journal Proceedings of the National Academy of Sciences (PNAS), shows that 115,000 years ago Neanderthal groups from Los Aviones Cave in Murcia, Spain, were already consuming molluscs following a clearly seasonal pattern, particularly during the colder months from November to April.

For decades, the ability of Neanderthals to adapt to coastal environments and exploit marine resources in an organized manner has been the subject of intense debate in archaeology and human evolution.

Traditionally, the regular consumption of shellfish and seasonal planning were considered traits exclusive to Homo sapiens.

But the new findings challenge that theory, according to the Spanish research team.

They analyzed marine mollusc remains — including small gastropods and limpets — recovered from Los Aviones Cave at an unprecedented resolution.

The results show that Neanderthals not only collected shellfish sporadically but also possessed a deep understanding of marine ecological cycles, anticipating by thousands of years behaviors later documented in modern humans from the region.

The research team were able to determine the season in which a mollusc was consumed thousands of years by analyzing the oxygen isotopic signal preserved in the carbonate of their shells.

They explained that as the incorporation of heavier or lighter oxygen isotopes depends primarily on seawater temperature.

Study lead author Asier García-Escárzaga said: "By reconstructing variation during shell growth, these values act as a prehistoric thermometer.

"This makes it possible to infer temperature changes as well as the exact time of year when a mollusc was collected, revealing new details about seasonal consumption patterns."

He says the results represent a milestone, as they are the first obtained for such early stages of human evolution.

García-Escárzaga, from the University of Burgos, Spain, said: "They consumed marine resources throughout the year, but with a very clear preference for winter and autumn months.

"This pattern, very similar to that developed by more recent populations of modern humans in Europe and other regions, cannot be coincidental."

He says winter collection coincides with periods when certain mollusc species have higher meat yield and improved flavor and texture due to their reproductive cycles.

The researchers believe Neanderthal populations may have avoided collecting shellfish in summer to minimize health risks, such as the proliferation of toxic algae or the rapid decomposition of shellfish due to heat, demonstrating a conscious and safe management of marine resources.

They say their findings suggest that Neanderthals and modern humans may have been more similar than previously thought.

The study also highlights that they enjoyed a "diversified" diet incorporating high-quality marine proteins — rich in Omega-3 and zinc — which are essential for brain development and reproductive health.

García-Escárzaga added: "What we see at Los Aviones is a fully modern subsistence strategy.

"This discovery reinforces the idea that Neanderthals possessed cognitive, social and economic capacities comparable to our own, establishing the Iberian Peninsula as a key region for understanding the complexity of our closest ancestors."