| Odontoceti | |
|---|---|
 A Dusky Dolphin. | |
| Scientific Classification | |
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Mammalia |
| Order | Cetacea |
The toothed whales form a suborder of the cetaceans, including sperm whales, beaked whales, dolphins, and others. As the name suggests, the suborder is characterized by the presence of teeth rather than the baleen of other whales.
Characteristics[]
Toothed whales have a single blowhole on the tops of their head (while the baleen whales possess two of them). The nostrils are not fused; one has become dominant over the other.
As an adaptation for their echolocation, toothed whale skulls have become asymmetric. Their brains are relatively big, although more significant growth did not occur before their echolocation started to evolve. Toothed whales' brains have a poor connection between the two hemispheres. The fatty organ called a melon on their heads is used like a lens to focus sound waves for echolocation. Vocal cords are not present; their sounds are produced in the blowhole system, instead. Toothed whales have lost their sense of smell, as well as their saliva glands. Except for the sperm whale, most toothed whales are smaller than the baleen whales. The teeth differ considerably among the species. They may be numerous, with some dolphins bearing over 100 teeth in their jaws. At the other extreme are the narwhal with its single long tusk and the almost toothless beaked whales with bizarre teeth only in males. Not all species are believed to use their teeth for feeding. For instance, the sperm whale likely uses its teeth for aggression and showmanship.
Behaviour[]
Vocalizations
Vocalizations are of great importance to toothed whales. While many species also maintain a broad variety of calls to communicate, all species investigated so far use short click sounds for purposes of echolocation. Sperm whales use low frequencies (a few to perhaps 50 Hz), while others employ more narrow-band, high-frequency sounds (porpoises, Cephalorhynchus species such as Hector's dolphin). Most dolphin species use very broad-band clicks.
Movement
Most toothed whales swim rapidly. The smaller species occasionally ride waves, such as the bow waves of ships. Dolphins can be frequently encountered this way. They are also famous for their acrobatic breaching from the water, e.g. the spinner dolphin.
Taxonomy[]
Order Cetacea
Suborder Odontoceti
Superfamily Delphinoidea
Family Albireonidae Genus Albireo Family Delphinidae Subfamily Delphininae Genus Delphinus Short-beaked Common Dolphin, Delphinus delphis Long-beaked Common Dolphin, Delphinus capensis Arabian Common Dolphin, Delphinus tropicalis Genus Lagenodelphis Fraser's Dolphin, Lagenodelphis hosei Genus Sousa Atlantic Humpback Dolphin, Sousa teuszi Indian Humpback Dolphin, Sousa plumbea Chinese White Dolphin, Sousa chinensis Genus Stenella Pantropical Spotted Dolphin, Stenella attenuata Atlantic Spotted Dolphin, Stenella frontalis Spinner Dolphin, Stenella longirostris Clymene Dolphin, Stenella clymene Striped Dolphin, Stenella coeruleoalba Genus Tursiops Common Bottlenose Dolphin, Tursiops truncatus Indo-Pacific Bottlenose Dolphin, Tursiops aduncus Burrunan Dolphin, Tursiops australis Subfamily Lissodelphininae Genus Cephalorhynchus Commerson's Dolphin, Cephalorhynchus commersonii Chilean Dolphin, Cephalorhynchus eutropia Heaviside's Dolphin, Cephalorhynchus heavisidii Hector's Dolphin, Cephalorhynchus hectori Genus Lissodelphis Northern Right Whale Dolphin, Lissodelphis borealis Southern Right Whale Dolphin, Lissodelphis peronii Subfamily Orcininae Genus Feresa Pygmy Killer Whale, Feresa attenuata Genus Globicephala Long-finned Pilot Whale, Globicephala melas Short-finned Pilot Whale, Globicephala macrorhyncus Genus Grampus Risso's Dolphin, Grampus griseus Genus Orcaella Irrawaddy Dolphin, Orcaella brevirostris Australian Snubfin Dolphin, Orcaella heinsohni Genus Orcinus Killer Whale, Orcinus orca Genus Peponocephala Melon-headed Whale, Peponocephala electra Genus †Platalearostrum †Hoekman's Blunt-snouted Dolphin, Platalearostrum hoekmani Genus Pseudorca False Killer Whale, Pseudorca crassidens Subfamily Stenoninae Genus Sotalia Tucuxi, Sotalia fluviatilis Costero, Sotalia guianensis Genus Steno Rough-toothed Dolphin, Steno bredanensis incertae sedis Genus Lagenorhynchus White-beaked Dolphin, Lagenorhynchus albirostris Atlantic White-sided Dolphin, Lagenorhynchus acutus Pacific White-sided Dolphin, Lagenorhynchus obliquidens Dusky Dolphin, Lagenorhynchus obscurus Black-chinned Dolphin, Lagenorhynchus australis Hourglass Dolphin, Lagenorhynchus cruciger Family †Kentriodontidae Subfamily Kentriodontinae Genus Belonodelphis Genus Delphinodon Genus Incacetus Genus Kentriodon Genus Macrokentriodon Genus Microphocaena Genus Rudicetus Genus Tagicetus Subfamily Lophocetinae Genus Hadrodelphis Genus Liolithax Genus Lophocetus Subfamily Pithanodelphininae Genus Atocetus Genus Leptodelphis Genus Pithanodelphis Genus Sophianacetus incertae sedis Genus Sarmatodelphis Genus Kampholophos Family Monodontidae Subfamily Delphinapterinae Genus Delphinapterus Beluga, Delphinapterus leucas Genus † Denebola Subfamily Monodontinae Genus Monodon Narwhal, Monodon monoceros Family † Odobenocetopsidae Genus Odobenocetops Family Phocoenidae Subfamily Phocoeninae Genus Neophocaena N. phocaeniodes - Finless Porpoise Genus Phocoena P. phocoena - Harbour Porpoise P. sinus - Vaquita P. dioptrica - Spectacled Porpoise P. spinipinnis - Burmeister's Porpoise Genus †Australithax Genus †Lomacetus Genus †Loxolithax Genus †Piscolithax P. aenigmaticus P. longirostris P. boreios P. tedfordi Genus †Salumiphocaena Genus Phocoenoides P. dalli - Dall's Porpoise incertae sedis Genus †Septemriocetus S. bosselaersii Genus †Haborophocoena H. toyoshimai Genus †Numataphocoena N. yamashitai incertae sedis Genus †Delphinavus Genus †Graamocetus Genus †Lamprolithax Genus †Miodelphis Genus †Nannolithax Genus †Oedolithax Genus †Oligodelphis Genus †Palaeophocaena Genus †Platylithax Genus †Protodelphinus Genus †Sinanodelphis
Superfamily Platanistoidea
Family Platanistidae Genus Platanista Ganges and Indus River dolphin, Platanista gangetica Ganges River dolphin, P. g. gangetica Indus River dolphin, P. g. minor Family †Allodelphinidae Family †Squalodelphinidae Family †Squalodontidae Genus †Eosqualodon Genus †Phoberodon Genus †Squalodon Genus †Tangaroasaurus Family †Waipatiidae Genus †Waipatia †W. maerewhenua Family Iniidae Genus Inia Amazon River Dolphin, Inia geoffrensis Inia geoffrensis geoffrensis Bolivian River Dolphin, Inia geoffrensis boliviensis Inia geoffrensis humbotiana Genus †Meherrinia M. isoni Genus †Goniodelphis G. hudsoni Genus †Ischyrorhynchus I. vanbenedeni Genus †Saurocetes S. argentinus S. gigas Family Pontoporiidae Genus Pontoporia La Plata Dolphin, Pontoporia blainvillei Family Lipotidae Genus Lipotes Baiji, †Lipotes vexillifer
Superfamily Ziphioidea
Family Ziphiidae Incertae sedis Genus †Nenga Genus †Pterocetus Genus †Xhosacetus Subfamily Berardiinae Genus †Archaeoziphius Genus Berardius B. arnuxii, Arnoux's beaked whale B. bairdii, Baird's Beaked Whale Genus †Microberardius Subfamily Hyperoodontinae Genus †Africanacetus Genus Hyperoodon H. ampullatus, Northern Bottlenose Whale H. planifrons, Southern Bottlenose Whale Genus Indopacetus I. pacificus, Longman's Beaked Whale Genus Mesoplodon M. bidens, Sowerby's Beaked Whale M. bowdoini, Andrews' Beaked Whale M. carlhubbsi, Hubbs' Beaked Whale M. densirostris, Blainville's Beaked Whale M. europaeus, Gervais' Beaked Whale M. ginkgodens, Ginkgo-toothed Beaked Whale M. grayi, Gray's Beaked Whale M. hectori, Hector's Beaked Whale M. layardii, Strap-toothed Whale M. mirus, True's Beaked Whale M. peruvianus, Pygmy Beaked Whale M. perrini, Perrin's Beaked Whale M. stejnegeri, Stejneger's Beaked Whale M. traversii, Spade-toothed Whale Subfamily Ziphiinae Genus †Caviziphius? Genus †Choneziphius Genus †Globicetus Genus †Imocetus Genus †Izikoziphius Genus †Tusciziphius Genus Tasmacetus T. sheperdi, Shepherd's Beaked Whale Genus Ziphius Z. cavirostris, Cuvier's Beaked Whale
