You probably don’t think much about teeth until a dentist brings them up. But across the animal kingdom, tooth counts can get wild fast. Some sharks go through thousands in a lifetime. Slugs carry ...

These days, all fish have teeth. The shapes of their teeth vary according to diet, ranging from the little pegs of goldfish to the formidable, pointed teeth of sharks. But fish evolved from toothless ...

Scientists studied how the sea creatures, also known as chimaeras or ghost sharks, ended up with one of evolution’s most bizarre appendages. By Jack Tamisiea Life in the ocean’s dark depths can be ...