Typical lizard locomotion is quadrupedal, however, bipedalism is a behavior exhibited by over 50 species of lizards. During bipedal locomotion, the forelimbs leave the ground and the trunk of the lizard is elevated. Only the hindlimbs power movement. There seems to be no speed or cost advantage to bipedal locomotion over quadrupedal locomotion, which makes this behavior even more fascinating.
One of the lizards known for this behavior, Basiliscus basiliscus is more commonly known as the Jesus Christ Lizard because it exhibits bipedal locomotion through water. These lizards live in tropical areas near water from Mexico to northern South America and are mostly arboreal and very agile. Bipedal motion through water is used as an escape mechanism.
The video demonstrates the mechanics of this movement. The hindlimbs arc laterally with each step, the spine undulates laterally to maintain balance, and the pelvis is rotated to increase stride length.
Bipedalism is employed by a wide variety of lizards and can manifest differently for each species. This site provides general information about the mechanics, ontogeny, phylogeny, and adaptation of bipedalism using specific examples to illustrate each concept.
|Content by Juliana M. Arrighi and Mikella Procopio; Title photo by Marcel Burkhard|