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| | Cetaceans |
 | | Odontocetes bear teeth typically numerous and peglike, although sometimes modified, as in the single tusk of the narwhal or the odd, fanglike lower teeth of the beaked whales. |
 | | Some baleen whales, most famously the humpack whales, are known for the strange and complex songs they produce; their function is not clear, but unlike toothed whales, baleen whales do not use their songs for echolocation. |
 | | These include the baleen whale families Balaenopteridae (rorqual whales, including the blue whale) and Balaenidae (right whales), and the toothed whale families Delphinidae (dolphins and killer whales), Physeteridae (sperm whales), Monodontidae (belugas and narwhals), Phocaenidae (porpoises), and Ziphiidae (beaked whales). |
| www.ucmp.berkeley.edu /mammal/cetacea/cetacean.html (1271 words) |
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