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Limited bipedalism in non-mammals (and non-birds)

Bipedalism is unknown among the amphibians. Among the non- archosaur reptiles bipedalism is rare, but it is found in the "reared-up" running of lizards such as agamids and monitor lizards. Many reptile species will also temporarily adopt bipedalism while fighting. One genus of basilisk lizard can run bipedally across the surface of water for some distance. Among arthropods, cockroaches are known to move bipedally at high speeds. Bipedalism is rarely found outside terrestrial animals, though at least two species of octopus walk bipedally on the sea floor using two of their arms, allowing the remaining arms to be used to camouflage the octopus as a mat of algae or a floating coconut.