Lagomorpha

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Lagomorphs[1]
Temporal range: Late Paleocene–Recent
European Rabbit, Oryctolagus cuniculus, in Tasmania
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Eutheria
Magnorder: Boreoeutheria
Superorder: Euarchontoglires
Order: Lagomorpha
Brandt, 1855
Families

Leporidae
Ochotonidae
Prolagidae (extinct)

Range of Lagomorpha

The lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (hares and rabbits) and the Ochotonidae (pikas). The name of the order is derived from the Greek lagos (λαγος, "hare") and morphē (μορφή, "form").

Contents

Evolution [edit]

Though these mammals can resemble rodents (order Rodentia) and were classified as a superfamily in that order until the early 20th century, they have since been considered a separate order. For a time it was common to consider the lagomorphs only distant relatives of the rodents, to whom they merely bore a superficial resemblance.

The evolutionary history of the lagomorphs is still not well understood. Until recently, it was generally agreed that Eurymylus, which lived in eastern Asia and dates back to the late Paleocene or early Eocene, was an ancestor of the lagomorphs.[2] More recent examination of the fossil evidence suggests the lagomorphs may have instead descended from Anagaloidea, also known as mimotonids, while Eurymylus was more closely related to rodents (although not a direct ancestor).[3] The leporids first appeared in the late Eocene and rapidly spread throughout the Northern Hemisphere; they show a trend towards increasingly long hind limbs as the modern leaping gait developed. The pikas appeared somewhat later in the Oligocene of eastern Asia.[4]

Characteristics [edit]

Lagomorphs differ from rodents in that:

  • they have four incisors in the upper jaw (not two, as in the Rodentia);
  • they are almost strictly herbivorous (unlike rodents, many of which will eat both meat and vegetation);[5][6][7]

However, they resemble rodents in that their teeth grow throughout their lives, thus necessitating constant chewing to keep them from growing too long.

Classification [edit]

References [edit]

  1. ^ a b Hoffman, R. S.; Smith, A. T. (2005). "Order Lagomorpha". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. pp. 185–211. ISBN 978-0-8018-8221-0. OCLC 62265494. 
  2. ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 285. ISBN 1-84028-152-9. 
  3. ^ Rose, Kenneth David (2006). The Beginning of the Age of Mammals. The Johns Hopkins University Press. p. 315. ISBN 0-8018-8472-1. 
  4. ^ Savage, RJG, & Long, MR (1986). Mammal Evolution: an illustrated guide. New York: Facts on File. pp. 128–129. ISBN 0-8160-1194-X. 
  5. ^ "Snowshoe Hare". eNature: FieldGuides. eNature.com. 2007. Retrieved 2008-03-23. 
  6. ^ Best TL, Henry TH (1994-06-02). "Lepus arcticus". Mammalian Species 457 (457): 1–9. doi:10.2307/3504088. ISSN 00763519. JSTOR 3504088. OCLC 46381503. 
  7. ^ "Column 105: Pikas are not picky eaters". yourYukon (Environment Canada: Pacific and Yukon Region). 1998. Retrieved 2008-03-23. 
  8. ^ The Paleobiology Database Lagomorpha entry Accessed on 13 May 2010