AskDefine | Define reptile

Dictionary Definition

reptile n : any cold-blooded vertebrate of the class Reptilia including tortoises turtles snakes lizards alligators crocodiles and extinct forms [syn: reptilian]

User Contributed Dictionary

English

Etymology

Middle English reptil< Old French reptile< rēptile, neuter of reptilis, "creeping" < Latin rēpō "to creep" < PIE *rep-, "to creep, slink" (Pokorny; Watkins, 1969).

Noun

  1. A cold-blooded vertebrate of the Class Reptilia.

Translations

a cold-blooded vertebrate

See also

Tamil : oorvana

Latin

Adjective

rēptile

Extensive Definition

"Sauropsida" redirects here.
Reptiles are air-breathing, cold-blooded vertebrates that have skin covered in scales as opposed to hair or feathers. They are tetrapods (having or having descended from vertebrates with four limbs) and amniotes, whose embryos are surrounded by an amniotic membrane. Modern reptiles inhabit every continent with the exception of Antarctica, and are represented by four living orders:
The majority of reptile species are oviparous (egg-laying) although certain species of squamates are capable of giving live birth. This is achieved, either through ovoviviparity (egg retention), or viviparity (offspring born without use of calcified eggs). Many of the viviparous species feed their fetuses through various forms of placenta analogous to those of mammals with some providing initial care for their hatchlings. Extant reptiles range in size from the newly-discovered Jaragua Sphaero, at 1.6 cm (0.6 in), to the Saltwater Crocodile, at up to at least 7 m (23 feet).

Classification

History of classification

From the classical standpoint, reptiles included all the amniotes except birds and mammals. Thus reptiles were defined as the set of animals that includes crocodiles, alligators, tuatara, lizards, snakes, amphisbaenians and turtles, grouped together as the class Reptilia (Latin repere, "to creep"). This is still the usual definition of the term. However, in recent years, many taxonomists have begun to insist that taxa should be monophyletic, that is, groups should include all descendants of a particular form. The reptiles as defined above would be paraphyletic, since they exclude both birds and mammals, although these also developed from the original reptile. Colin Tudge writes:

Synonyms, Antonyms and Related Words

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