The Same Shells, 20,000 Years Apart

A cave on the Mediterranean coast of southern Türkiye held two tenants in sequence. Neanderthals lived there first, from roughly 77,000 to 59,000 years ago. Then Homo sapiens moved in, staying until around 47,000 years ago. Different species, different millennia, no overlap in occupancy. And yet when researchers sifted through the sediment layers, they found the same stone tools, the same prey animals, and, most strangely, the same shells.

Not shells they were eating. Both groups selectively collected a specific type of marine seashell with virtually no food value: a small, decorative gastropod called Columbella rustica. Until now, that kind of shell collecting was thought to belong to modern humans alone. Finding it in Neanderthal layers of the same cave, tied to the same strong preference for that particular shell, is what turns this from an interesting excavation into something harder to explain.

Naoki Morimoto, a co-author of the study at Kyoto University, said the shared preference points to a common cultural judgment about the shell, something both groups apparently found valuable or attractive for reasons that had nothing to do with survival. The two species were not living parallel lives that happened to resemble each other; they were exchanging ideas and traditions, arriving at a shared behavior with no practical use beyond its cultural meaning.

The study, published in PNAS, does not claim the two groups met in that cave. What it does claim is more unsettling: that something, a preference, a practice, a sense of beauty, crossed a species boundary and lasted. Maybe through direct contact elsewhere in the Levant. Maybe through inheritance from a shared ancestor. Maybe through a mechanism nobody has named yet. How long the behavior lasted, how far it spread, and whether it tracks with interbreeding are questions the evidence does not yet answer.

The shells were there. Both of them wanted them. The rest is still open.

Read the full story at Scientific American, July 2026

Hot Take: Two species incapable of ever meeting agreed on the same useless, shiny thing for thousands of years, with no training montage and no group chat to coordinate it. Good taste, apparently, doesn't need a shared species to spread. It just needs a decent shell.