STANFORD, Calif. (KGO) -- If you ever come face-to-face with the wrong kind of shark, there's something you probably want to avoid. Just a hint: they're long and really sharp. But now, researchers at ...

(Close-up of a shark with sharp teeth. Credit: GIOVANNI NITTI / Shutterstock.) Shark teeth are a marvel of evolution. They are so sharp that many island cultures once used them as weapons and tools to ...

PORTLAND, Maine — Sharks are the most feared predators in the sea, and their survival hinges on fearsome teeth that regrow throughout their lives. But changes in the ocean's chemistry could put those ...