C. planus tooth from Bakersfield, California.

C. planus was a fast, powerful shark cruising the warm Pacific waters off California about 15–16 million years ago. Found at the legendary Shark Tooth Hill its broad, serrated teeth tell the story of a confident hunter that fed on fish, rays, smaller sharks, and likely young marine mammals when the opportunity arose. This shark wasn’t lurking on the bottom, it was constantly on the move, patrolling open water and coastal zones, cutting through prey with ease. Each tooth is a small snapshot of a busy Miocene ocean, when whales, seals, and sharks packed these seas and predators like C. planus played a key role in keeping that ancient ecosystem in balance.