FACTOID # 28: Austin, Texas has more people than Alaska.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Cetacean" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Cetacean


Cetaceans

Humpback Whale breeching
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Suborders

Mysticeti
Odontoceti
(see text)

The order Cetacea includes whales, dolphins and porpoises. Cetus is Greek ketos ("sea monster"). Cetology is the branch of marine science accociated with the study of cetaceans.


Cetaceans are the mammals most fully adapted to aquatic life. Their body is fusiform (spindle-shaped). The forelimbs are modified into flippers. The tiny hindlimbs are vestigial, they do not attach to the backbone and are hidden within the body. The tail has horizontal flukes. Cetaceans are nearly hairless, and are insulated by a thick layer of blubber. Cetacea contains ten families, and about 80 species.

Contents

Evolution

Cetaceans are descendants of land-living mammals, most likely of the Artiodactyl order. They entered the water roughly 50 million years ago. See evolution of cetaceans for the details.


Taxonomic listing

The classification here closely follows "Marine Mammals of the World: Systematics and Distribution" by Dale W. Rice (1998). The work has become the standard taxonomy reference in the field. Differences reflect usage of common names and further discoveries since the publication of that work.

References

  • Rice, Dale W. (1998). Marine mammals of the world: systematics and distribution. Society of Marine Mammalogy Special Publication Number 4. 231 pp. See the Society's website (http://www.marinemammalogy.org/publications.htm) for further details.

External links

  • American Cetacean Society (http://www.acsonline.org/)
  • British Cetacean Site (http://www.crru.org.uk/) especially interesting is taxonomy (http://www.crru.org.uk/education/factfiles/taxonomy.htm)
  • Cetacea.org homepage (http://www.cetacea.org/)
  • Walker's Mammals of the World Online - Cetaceans (http://www.press.jhu.edu/books/walkers_mammals_of_the_world/cetacea/cetacea.html#genera)
  • Tursiops.org: Current Cetacean-related news (http://www.tursiops.org/)
Mammals
Monotremata

Placentalia: Xenarthra | Dermoptera | Desmostylia | Scandentia | Primates | Rodentia | Lagomorpha | Insectivora | Chiroptera | Pholidota | Carnivora | Perissodactyla | Artiodactyla | Cetacea | Afrosoricida | Macroscelidea | Tubulidentata | Hyracoidea | Proboscidea | Sirenia

Marsupialia: Didelphimorphia | Paucituberculata | Microbiotheria | Dasyuromorphia | Peramelemorphia | Notoryctemorphia | Diprotodontia





  Results from FactBites:
 
Cetacea - Wikipedia, the free encyclopedia (1357 words)
Cetaceans are nearly hairless, and are insulated by a thick layer of blubber.
Cetaceans evolved from land mammals (most likely from certain hoofed carnivores distantly related to hippopotamuses) that returned to the sea about 50 million years ago.
From this, cetaceans can discern the size, shape, surface characteristics and movement of the object, as well as how far away it is. This is called echolocation, and with it cetaceans can search for, chase and catch fast-swimming prey in total darkness.
Mammals - Resources - Cetacean FAQs (1954 words)
However, it is the cetaceans that are the most specialised in the aquatic environment and for a long time even the most basic aspects of their biology remained a mystery.
Cetaceans sleep by floating at the surface of the sea with their blowholes exposed, some species rest during the day and others at night.
Cetaceans often live in environments where there is little light, such as the deep ocean or the turbid waters of rivers.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m