Piranhas belong to a family of bony fish characterized by highly developed dentition. They’re cousins to the pacu fish, which has dentition eerily similar to human teeth. Unlike pacu teeth, which are ...

Saber teeth — the large fangs of saber-tooth cat fame — are fearsome. They evolved at least five times in predators that are now extinct, but there's been something of a mystery as to why. Saber teeth ...