Neanderthals didn't just hunt mammoths. They actually knew how to fish, researchers discover.

Doyle Rice, USA TODAY
A bust of a Neanderthal man at the Smithsonian's National Museum of Natural History.

Neanderthals weren't the club-wielding brutes of popular legend, hunting and eating only woolly mammoths in frozen northern climates. A new study, for the first time, suggests they were skilled fishermen and that seafood was a key ingredient in their diets.  

In fact, over 80,000 years ago, Neanderthals were feeding themselves regularly on fish and other marine life. The first evidence of this has been found in a coastal cave in Portugal.

Filled with fish bones and crustacean shells that researchers know were left behind by Neanderthals, the cave "provides the first record of significant marine resource consumption among Europe's Neanderthals," according to the study.

The new study reveals fishing and shellfish gathering contributed significantly to the subsistence economy of the Neanderthals. Up until now, the use of the sea as a source of food at that time had only been attributed to modern humans (Homo sapiens) in Africa.

In addition to land-based foods, the study suggests that the Neanderthal diet also included mussels, crustaceans and fish as well as waterfowl and marine mammals such as dolphins and seals. Food from the sea is rich in omega-3 fatty acids and other fatty acids that promote the development of brain tissue.

"If this common consumption of marine resources played an important role in the development of cognitive skills, it did so on the entire humanity, including Neanderthals, and not only the African population that spread later," said study lead author João Zilhão, a researcher at the University of Barcelona.

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The increased cognitive ability also boosted Neanderthal's ability for abstract thought, scientists believe.

"Among other influences, this could also explain the early appearance of a culture of modern people that used symbolic artifacts, such as body painting with ochre, the use of ornaments or the decoration of containers made of ostrich eggs with geometric motifs," explained study co-author Dirk Hoffmann of the University of Gottingen in Germany.

"Such behavior reflects human's capacity for abstract thought and communication through symbols, which also contributed to the emergence of more organized and complex societies of modern humans."

The findings jibe with recent evidence that Neanderthals had “surfers’ ear” and may also have dived to collect shells for use as tools, according to the Guardian. Previous finds in Spain have shown they decorated seashells and were producing rock art 65,000 years ago.

“Forget about this Hollywood-like image of the Neanderthal as this half-naked primitive that roamed the steppe tundra of northern Europe hunting for mammoths and other megafauna with poor and inefficient weapons,” Zilhão told the Guardian. “The real Neanderthal is the Neanderthal who is in southern Europe.”

The study was published in the peer-reviewed journal Science. 

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This article originally appeared on USA TODAY: Neanderthals knew how to fish, regularly ate seafood, study says