Put this on the list of things we are glad are extinct: Sharks with buzzsaws for mouths:
Apparently, the weird spiral jaw of the helicoprion was found a long time ago, but scientists were never sure what exactly to make of it and what the creature actually looked like. For instance, here’s one attempted depiction I found on the net:
But now for some reason the scientists are pretty sure it looked like a shark with its bottom jaw basically a buzzsaw. It’s a shark with a buzzsaw for a mouth. Don’t know how that went extinct. Maybe it dominated the whole animal kingdom so much that eventually it just got bored. Perhaps it built rocket ships to attack other planets in space. There are numerous theories, all as likely correct as the other. You can never be sure with buzzsaw-mouthed sharks. I just hope we have the wisdom to mount rocket launchers on dinosaurs as a defense in case they ever come back.