Therians Temporal range: Early Cretaceous-Recent, 125–0 Ma |
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A cat (Felis catus) with her kittens | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Subclass: | Theria Parker & Haswell, 1897 [1] |
Infraclasses | |
Theria (pronounced /ˈθɪəri.ə/, from the Greek θηρίον, wild beast) is a subclass of mammals[2] that give birth to live young without using a shelled egg, including both eutherians (placental mammals) and metatherians (marsupials and their ancestors). The only omitted extant mammal group is the egg-laying monotremes.
[edit] Taxonomy
The rank of 'Theria' may vary depending on the classification system used. The textbook classification system by Vaughan et al. (2000)[3] gives the following:
Class Mammalia
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In the above system Theria is a subclass. Alternatively, in the system proposed by McKenna and Bell (1997)[4] it is ranked as a supercohort under the subclass Theriiformes:
Class Mammalia
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Another classification proposed by Luo et al. (2002)[5] does not assign any rank to the taxonomic levels, but uses a purely cladistic system instead.
[edit] References
- ^ ITIS Standard Report Page: Theria
- ^ Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. "Subclass Theria". Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/classification/Theria.html.
- ^ Vaughan, Terry A., James M. Ryan, and Nicholas J. Czaplewski. 2000. Mammalogy: Fourth Edition. Saunders College Publishing, 565 pp. ISBN 0-03-025034-X
- ^ McKenna, Malcolm C., and Bell, Susan K. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York, 631 pp. ISBN 0-231-11013-8
- ^ Luo, Z.-X., Z. Kielan-Jaworowska, and R. L. Cifelli. 2002. In quest for a phylogeny of Mesozoic mammals. Acta Palaeontologica Polonica, 47:1-78.
[edit] See also
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