Whales, Dolphins, and porpoises Order Cetacea
Abstract Cetaceans are aquatic mammals that breathe air and suckle their young. As a result of modifications associated with life in water, they are fishlike in form. Many dolphins have upright, sharklike dorsal fins; however, the tail of a dolphin is flattened horizontally, whereas a shark’s tail i...
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| Format: | Book Part |
| Language: | unknown |
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Oxford University PressNew York, NY
2009
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| Online Access: | http://dx.doi.org/10.1093/oso/9780195343229.003.0014 https://academic.oup.com/book/chapter-pdf/53078546/isbn-9780195343229-book-part-14.pdf |
| Summary: | Abstract Cetaceans are aquatic mammals that breathe air and suckle their young. As a result of modifications associated with life in water, they are fishlike in form. Many dolphins have upright, sharklike dorsal fins; however, the tail of a dolphin is flattened horizontally, whereas a shark’s tail is vertical. Unlike fish, cetaceans breathe through blowholes (nos- trils) located on the top of their head. Whales and dolphins do not resemble other orders of mammals, but are related to artiodactyls (progenitors of modern ungulates), based on similar fossil ancestors and other evidence. Cetaceans are divided into 2 major groups, the toothed whales (suborder Odontoceti) and the baleen whales (suborder Mysticeti). |
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