All dolphins have conical teeth that are used for biting and trapping prey, such as crustaceans and fish, but are not used for chewing. Dolphins swallow their prey whole. Dolphins fall into the odontoceti, or "toothed whale," suborder of cetaceans, the order that includes all whales, dolphins and porpoises.
Research indicates that dolphins may use their teeth as receivers for echolocation signals, a type of active sonar that cetaceans use to navigate the ocean and locate prey.
Porpoises, which closely resemble dolphins, also have teeth, but theirs are spade-like rather than conical.
There are approximately 73 species of toothed cetaceans, including the sperm whale, killer whale, bottlenose dolphin and beluga whale.