Theria

From Wikipedia, the free encyclopedia

Jump to: navigation, search
Therian
Fossil range: Jurassic or Early Cretaceous-Recent
House Mouse, Mus musculus
House Mouse, Mus musculus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Subclass: Theria
Parker & Haswell, 1897
Infraclasses

Metatheria
Eutheria
Trituberculata

Theria (pronounced /ˈθɪərɪə/, from the Greek θηρίον, wild beast) is a subclass of mammals[1] that give birth to live young without using a shelled egg, including both eutherians (placental mammals) and metatherians (marsupials and their ancestors).

Contents

[edit] Extent

The subclass includes humans. They have external ears, most can suckle on a nipple, and have an ankle specialized for power and range of motion. Therians are often classified by their specialized dentition.

Almost all currently extant (not extinct) mammals are therians. The only exceptions are the platypus and the echidnas (spiny anteater), both of which are prototherian monotremes.

[edit] Bibliography

  • Vaughan, Terry A., James M. Ryan, and Nicholas J. Czaplewski. 2000. Mammalogy: Fourth Edition. Saunders College Publishing, 565 pp. ISBN 0-03-025034-X

[edit] References

  1. ^ 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. 

[edit] External links

Personal tools