5. Helicoprion: The Enigmatic Whirling Predator
Helicoprion, a 270-million-year-old fish, was the source of one of the most puzzling fossil mysteries. Initially identified as strange petrified whirls of elongated teeth, this creature’s feeding apparatus stumped paleontologists for over a century. In 2013, a study finally revealed that the coiled tooth-whirl completely filled the lower jaw in a buzzsaw-like formation. As the fish closed its jaw, the teeth rotated backward in a saw-like motion, allowing it to catch and consume its prey. The largest Helicoprion specimen ever found had a two-foot-wide jaw, making it a truly fearsome predator.
