Limbless vertebrates

Limbless vertebrates

Many vertebrates have evolved limbless forms. Reptiles have on a number of occasions evolved into limbless forms - snakes, amphisbaenia, and legless lizards (limb loss in lizards has evolved independently several times). The same is true of amphibians - caecilians, Sirenidae (a clade of salamanders that are limbless except for atrophied front limbs), Amphiumidae (a clade of salamander with extremely atrophied limbs that appear non-functional) and at least two extinct groups (Aïstopoda and Lysorophia). Legless forms of reptiles and amphibians probably evolved so as to be able to move underground or in water more easily.

There are also a number of fish with elongated bodies that have no or reduced appendage-like fins, for example eels and swamp eels. Hagfish and lamprey also do not have appendage-like fins, they may not have lost them, but simply retained the form that vertebrates had before they evolved limbs.Fact|date=August 2008

There are no known limbless species of mammal or bird.

See also

*Terrestrial locomotion in animals


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Terrestrial locomotion — [ horse an erect stanced unguligrade quadruped with a galloping gait. An animation of photos by Eadweard Muybridge] Terrestrial locomotion has evolved as animals adapted from aquatic to terrestrial environments. Locomotion on land raises… …   Wikipedia

  • locomotion — /loh keuh moh sheuhn/, n. the act or power of moving from place to place. [1640 50; see LOCOMOTIVE, MOTION] * * * Any of various animal movements that result in progression from one place to another. Locomotion is classified as either… …   Universalium

  • Snake — Ophidian redirects here. For the professional wrestler, see The Osirian Portal. This article is about the animal. For other uses, see Snake (disambiguation). Snakes Temporal range: Early Cretaceous – Recent, 112–0 Ma …   Wikipedia

  • terrestrial locomotion — ▪ behaviour       any of several forms of animal movement such as walking and running, jumping (saltation), and crawling. Walking and running, in which the body is carried well off the surface on which the animal is moving (substrate), occur only …   Universalium

  • Pygopodidae — Taxobox name = Pygopodidae image width = 250px image caption = Pygopus lepidopodus ,from Brehms Tierleben, (1892) regnum = Animalia phylum = Chordata classis = Reptilia ordo = Squamata subordo = Scleroglossa infraordo = Gekkota familia =… …   Wikipedia

  • Glass lizard — Eastern glass lizard (Ophisaurus ventralis) Scientific classification Kingdom: Animalia …   Wikipedia

  • Caecilian — This article is about an order of amphibians. For the bishop of Carthage, see Caecilianus. Caecilians Temporal range: 170–0 Ma …   Wikipedia

  • lizard — /liz euhrd/, n. 1. any of numerous scaly reptiles of the suborder Sauria, order Squamata, typically having a moderately elongate body, a tapering tail, and two pairs of legs held outward from the body, comprising mostly terrestrial and burrowing… …   Universalium

  • reptile — reptilelike, adj. reptiloid /rep tl oyd /, adj. /rep til, tuyl/, n. 1. any cold blooded vertebrate of the class Reptilia, comprising the turtles, snakes, lizards, crocodilians, amphisbaenians, tuatara, and various extinct members including the… …   Universalium

  • snake — snakelike, adj. /snayk/, n., v., snaked, snaking. n. 1. any of numerous limbless, scaly, elongate reptiles of the suborder Serpentes, comprising venomous and nonvenomous species inhabiting tropical and temperate areas. 2. a treacherous person; an …   Universalium

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”