Cetacean: Introduction



Cetaceans are an order of marine mammals which contains whales, dolphins and porpoises. This means they are more closely related to humans than to sharks and fishes. The group is split into two sub-orders; Mysticeti (baleen whales) and Odontoceti (toothed whales). The toothed whales are the most diverse group, containing at least 70 species of dolphins, porpoises, and sperm whales.