48
edits
Changes
Jump to navigation
Jump to search
Lizard Taxonomy and Identification (view source)
Revision as of 15:05, 19 February 2010
, 15:05, 19 February 2010no edit summary
==Taxonomy==
==Taxonomy==
Reptiles are ectothermic vertebrates with scales or plates, right and left aortic arches, a partially divided heart and a single occipital condyle. Lizards are members of the reptilian order Squamata.
Reptiles are ectothermic vertebrates with scales or plates, right and left aortic arches, a partially divided heart and a single occipital condyle. Lizards are members of the reptilian order Squamata. The lizards and their snake descendants are the only living squamates. Excluding the snakes, lizards are still the most speciose extant reptiles, with about 4450 species.
Lizards occur on all continents, except Antarctica, and on most tropical and subtropical oceanic islands. This widespread occurrence denotes their broad ecological, physiological, and behavioural adaptations to extremely hot or cold climates, extremely arid to freshwater and marine habitats, and lowland to high-elevation regions. Their highest species diversity appears to be in semiarid habitats; for example, 53 species of lizards occur at one site in the Great Victoria Desert, Australia, and in some areas, particularly islands, densities can be greater than 3000 per hectare.
==Common species==
==Common species==