Did you ever imagine a fish with teeth sprouting out of its forehead? It sounds like something out of a sci-fi comic, but thanks to an AI generated newscast about spotted ratfish, you’re about to rethink everything you know about teeth!

We’ve always assumed teeth belong in mouths, right? Turns out, nature loves a plot twist. Meet the spotted ratfish, or Hydrolagus colliei, a mysterious creature sometimes called a ‘ghost shark.’ Scientists have just discovered that adult male ratfish sport hooked, toothy protrusions—right on their foreheads—used to grasp mates during reproduction. And these aren't just lookalikes; they're actual teeth, developed from the same tissue as your average chomper.

This jaw-dropping finding, highlighted in the Proceedings of the National Academy of Sciences, upends one of biology’s most basic rules. Karly Cohen, a researcher at the University of Washington, calls this discovery “insane” and “spectacular,” since it proves teeth aren’t just for eating—they might be for flirting, too!

How does this happen? The tenaculum, a white, peanut-shaped appendage between the eyes of male ratfish, is lined with real teeth. It develops from the dental lamina—the very tissue that forms teeth in the jaw—suggesting tooth-forming cells once wandered far beyond the mouth in early evolution. As if chimaeras, the ancient relatives of sharks, weren’t weird enough, only adult males get this extraordinary forehead spike that hooks and barbs during mating season. Cohen jokes that since sharks don’t have arms, they’ve evolved all sorts of creative ways to grab a partner underwater. Looks like ratfish took that to a whole new level, with a handy—which in this case means ‘foreheady’—toothed device.

To unravel the mystery, researchers at the University of Washington pulled off a modern science adventure, collecting hundreds of ratfish near San Juan Island and peering into their heads with micro-CT scans. The scans revealed both male and female ratfish start life with the tenaculum, but only males develop it into a full-fledged, toothy head spike. The team even checked fossils of ancient ratfish, confirming that this bizarre trait goes way back—making it not just a ‘weird one-off,’ but a relic of evolutionary history.

Michael Coates, a University of Chicago professor, explains that this is an epic case of evolution recycling old tricks for new purposes, using ancient tooth-making programs to create a head-mounted device essential for reproduction. Gareth Fraser at the University of Florida says it best: If some fish are growing teeth on their foreheads, who knows where else evolution is hiding a set of chompers?

AI generated newscasts about spotted ratfish are making waves online, and rightly so—this fish proves that nature always has a wild card up its sleeve, or in this case, its forehead. Next time you think you’ve seen it all in the animal kingdom, remember: there’s a whole world of forehead-teethed wonders out there, waiting to be AI-generated and discovered.