Toothed whale Toothed whale The toothed whales (systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales. Seventy-three species of toothed whales (also called odontocetes) are described. They are one of two living groups of cetaceans, the other being the baleen whales (Mysticeti), which have baleen instead of teeth. The two groups are thought to have diverged around 34 million years ago (mya). Toothed whales range in size from the and vaquita to the and sperm whale. Several species of odontocetes exhibit sexual dimorphism, in that
Captive killer whales twice that length or and a minimum depth of , giving a minimum volume of for two killer whales. Each additional killer whale requires a pool with an additional of volume. 9 CFR 3.104 also requires a minimum of surface area per killer whale in Table IV (the example with a cylindrical tank in diameter for two whales provides of surface area per killer whale). Swiss regulations require a larger minimum volume: × deep for two killer whales, or . The Alliance of Marine Mammal Parks and Aquariums (AMMPA) goes further, and recommends for two killer whales. The US exhibitors