Turtles

Turtles currently living do not have teeth.

An excerpt from the article 27 facts about turtles

Instead, the insides of their mouths are overgrown with sharp horn-like protuberances used to cut, hold and grind food. Some extinct species had teeth but became extinct about 160 million years ago. A recently discovered representative of turtles equipped with teeth is Sichuanchelys palatodentata.