Odontoceti

Odontoceti, the toothed whales, is a parvorder of cetaceans comprising roughly 73 living species, including dolphins, porpoises, beaked whales, river dolphins, and the sperm whale, ranging in size from the 1.4 meter, 54 kilogram vaquita to the 20 meter, roughly 100 ton sperm whale. Toothed whales are distinguished from the other major living cetacean group, the baleen whales, chiefly by their dentition: they possess conical teeth suited to catching fish and squid, rather than the baleen plates baleen whales use to filter feed. They also evolved echolocation and a distinctive blubber fat composition that baleen whales lack, adaptations that trace to the two lineages divergence roughly 34 million years ago from land-dwelling artiodactyl ancestors that became fully aquatic.