(Redirected from Legs)

Diagram of an insect leg
A 'leg' is the part of an
animal's
body that supports the rest of the animal above the ground and is used for
locomotion. The end of the leg furthest from the animal's body is often either modified or attached to another structure that is modified to disperse the animal's weight on the ground (see
foot).
In
bipedal vertebrate animals, the two lower limbs are usually referred to as the 'legs' and the two upper limbs as the 'arms' or 'wings' as the case may be.
Legs typically come in even-numbered quantities. Many
taxonomic groups are characterized by the number of legs its members possess.
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Uniped: 1
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Biped: 2
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Tripedal: 3
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Quadruped: 4
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Quinped: 5
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Arthropoda: 4, 6, 8, 12, or 14
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★ Some arthropods have more than a dozen legs; a few species possess over 100. Despite what their names might suggest,
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Centipedes typically have fewer than one hundred legs
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Millipedes have fewer than one thousand legs.
Evolution
The leg has evolved several times, most significantly among arthropods (crustaceans, insects, arachnids, et cetera) and vertebrates. In both cases, they are thought to have first evolved for locomotion underwater, then have been exploited for movement over land ever less desperate conditions as the generations passed.
The human leg
Main articles: Human leg
The bones of the human leg are:
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Tibia, or shin bones
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Fibula, or calf bones
See also
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Body plan
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Arthropod leg
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Terrestrial locomotion in animals
Sources
http://www2.merriam-webster.com/cgi-bin/mwmednlm