A brown crab, or Cancer pagurus, shown during low tide, is still eaten today in Portugal, Spain, Italy and France.

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Neanderthals living 90,000 years ago in a seafront cave, in what’s now Portugal, regularly caught crabs, roasted them on coals and ate the cooked flesh, according to a new study.

The finding is significant because it builds upon evidence that overturns the long-standing notion that a taste for seafood — rich in omega-3 fatty acids that are important for brain growth — was one of the unique factors that made our own species, Homo sapiens, smarter than other, now-extinct prehistoric humans, such as Neanderthals.

“Our results add an extra nail to the coffin of the obsolete notion that Neanderthals were primitive cave dwellers who could barely scrape a living off scavenged big-game carcasses,” said study author Dr. Mariana Nabais, a postdoctoral researcher at the Catalan Institute of Human Paleoecology and Social Evolution in Tarragona, Spain, in a news release.

Archaeologists excavating the site at Gruta da Figueira Brava, roughly 20 miles (32 kilometers) south of Lisbon, had also found the remains of shellfish. There were limpets, mussels and clams, but shell and pincer scraps from the brown crab were particularly numerous.

Scientifically known as Cancer pagurus, the brown crab is a species crab still commonly consumed today in Portugal, Spain, Italy and France.

This latest study found the Neanderthals hunted mostly larger adult crabs, suggesting they had been selected for the size, with a shell or carapace about 16 centimeters (6.3 inches) wide. Each crab would have provided around 200 grams (7 ounces) of crabmeat.

Patterns of damage to the crab shells and pincers ruled out the involvement of other predators such as birds or rodents, the study said. And crack marks seen on specimens found at the archaeological site were very similar to those produced when eating the crabs today, the study said, although Neanderthals would have used stone tools rather than modern-day metal hammers and cutlery to crack open the shellfish.

Crack marks seen on brown crab remains found at an archaeological cave site in Portugal were very similar to those produced when eating the same species today, the study said.

Black burn marks the researchers identified on the shells suggested that the crabs were roasted on hot coals to temperatures of between 300 and 500 degrees Celsius (572 and 932 degrees Fahrenheit) then cracked open to access the cooked flesh.

“Whether such foods were perceived as tasteful, reflected some sort of festivity, added social value to whoever harvested them, or had other consumption-associated meanings is beyond our grasp,” the study that published Tuesday in the journal Frontiers in Environmental Archaeology said.

While crabs aren’t easy to catch by hand, the study said it was likely they were caught in shallow low-tide rock pools near the cave, perhaps aided by spears to stun them. The study noted that Indigenous groups across North America have been documented harvesting crabs in this way.

Neanderthals were able to adapt to different environments, hunt a wide range of animals and make use of different types of food, the study underscored.

These hominins hunted big game. Neanderthals were able to kill and butcher giant elephants that could feed 100 people for a month, according to a February 1 study that analyzed ancient animal remains found at a dig site in Germany.

Neanderthals also cooked meals that combined plants and pulses like lentils, a November 2022 study revealed.