Cetacean Families (Whales, Dolphins, Porpoises)

This group gathers taxon/Mammal Families subcategory members that are themselves mammal families belonging to the infraorder Cetacea, the whales, dolphins and porpoises, fully aquatic mammals descended from land-dwelling artiodactyl ancestors that returned to the water tens of millions of years ago. It spans Delphinidae, the oceanic dolphin family and the largest cetacean family by number of species, Balaenopteridae, the rorqual family that includes the blue whale, the largest animal known to have ever lived, and Phocoenidae, the porpoise family, generally smaller and stockier than true dolphins, alongside toothed and baleen families adapted to feeding strategies ranging from echolocation-guided hunting of individual prey to filter-feeding enormous volumes of small schooling fish and krill. Every family gathered here breathes air through a blowhole at the top of the head and gives birth to fully aquatic live young, unable to survive even briefly out of water as an adult.