w&whale ì"ê´' | whale 881 replacement Whale Whales are a widely distributed and diverse group of fully marine placental marine mammals. They are simply an informal grouping within the infraorder Cetacea, usually excluding dolphins and porpoises. Whales, dolphins and porpoises belong to the order Cetartiodactyla with even-toed ungulates and their closest living relatives are the hippopotamuses, having diverged about 40 , 000, 000 years ago. The two parvorders of whales, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have split besides around 34 million in years past. The whales comprise eight extant families: Balaenopteridae (the rorquals), Balaenidae (right whales), Cetotheriidae (the pygmy correct whale), Eschrichtiidae (the gray whale), Monodontidae (belugas and narwhals), Physeteridae (the ejaculate whale), Kogiidae (the little and pygmy sperm whale), and Ziphiidae (the beaked whales). ...
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