Humans love to collect things, even if it doesn’t always make sense from an evolutionary point of view. From stamps, to comic books, to rare coins— If society attaches an emotional or financial value to objects, chances are that some people will collect them. Collecting trinkets may not sustain you physically, but the act indicates a certain level of cognitive ability and abstract thinking. But when did we first start collecting objects just because we liked them? Judging by relics discovered in a cave in Iberia, Spain, the act of collecting may go back at least as far as our Neanderthals.

In a study published on November 12 in the journal Quaternaryanalyzed an archaeological team led by researchers at the Universidad de Burgos 15 small marine fossils found in the fourth level of the Prado Vargas cave system in Burgos, Spain. While one artifact showed physical evidence of use as a hammer, the other 14 fossils showed no obvious physical wear or utility value. Additional evidence in the caves also points to the site functioning as a semi-permanent one The Neanderthal camp probably used for tool making, hunting or perhaps even ritual activities.

These shell fossils, which averaged less than two inches wide, were dated to about 39.8–54.6 thousand years ago during Upper Cretaceousand included remains of species such as early sea snails and saltwater clams. But, as researchers note, none of them are native to the cave’s immediate region. Instead, the team estimates that many of the fossil’s closest possible original locations were in geologic formations over 17 miles away.

Previous research shows Neanderthals engaged in cultural rituals such as ornamental crafts, cave wall art, and even family and social burials. Because of this, the experts argue that it is reasonable that the human ancestors likely participated in pastimes such as collecting objects that they found interesting or special.

“This would suggest that Neanderthals had psychological and behavioral traits similar to those of our species, for which gathering is a common and complex practice,” the authors wrote.

The researchers explained that, given that humans collect for a wide range of tangible and intangible reasons, Neanderthals may have collected the fossils due to any combination of factors, including “competition, cooperation, symbolism, selfishness, selflessness, a sense of continuity , marketing, or addiction.” But just as likely, these are the same reasons why Neanderthal descendants still love collectibles to this day.

“Perhaps … the people who collected them got pleasure from looking for them or finding them and keeping them,” researchers theorized. “Or they may have been objects of play, or perhaps even had a magico-religious role . . .”