Flipper (anatomy)

Penguin swimming. What is considered a "vestigial" wing is in fact a very effective flipper.

This green turtle is about to break the surface for air at Kona, Hawaii.

A flipper is a typically flat forelimb evolved for movement through water. Various creatures have evolved flippers, for example penguins (also called "wings"), cetaceans (e.g. dolphins and whales; usually called "fins"), pinnipeds, and reptiles such as some varieties of turtle and the now-extinct plesiosaurs, mosasaurs, ichthyosaurs, and metriorhynchids.

Some flippers are very efficient hydrofoils, analogous to wings (airfoils), used to propel and maneuver through the water with great speed and maneuverability (see Foil (fluid mechanics)). Some flippers are less foiled, with the appendages still apparent, as in the webbed forefeet seen in amphibious turtles.

See also

• Fish fin
• Homology (biology)

References

Fins, limbs and wings
Fins	Aquatic locomotion Cephalopod fin Fish locomotion Fin and flipper locomotion Caudal fin Dorsal fin Fish fin flipper Lobe-finned fish Ray-finned fish Pectoral fins
Limbs	Limb development Limb morphology digitigrade plantigrade unguligrade uniped biped facultative biped triped quadruped Arthropod Cephalopod Tetrapod dactyly Digit
Wings	Flying and gliding animals Bat wing Bird wing keel skeleton feathers Insect wing Pterosaur wing Wingspan
Evolution	Evolution of fish Evolution of tetrapods Evolution of birds Origin of birds Origin of avian flight Evolution of cetaceans Comparative anatomy Convergent evolution Analogous structures Homologous structures
Related	Animal locomotion Gait Robot locomotion Samara Terrestrial locomotion Tradeoffs for locomotion in air and water Rotating locomotion Undulatory locomotion