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Lizard Taxonomy and Identification (view source)
Revision as of 15:37, 19 February 2010
, 15:37, 19 February 2010no edit summary
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.
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.
==Taxonomy==
==Taxonomy==
Lizards are a very large and widespread group of the reptilian order Squamata. The nearly 7200 species of lizards are the most diverse and speciose living clade of reptiles; of course this total includes the worm lizards and snakes (which are actually reduced-limbed or limbless lizards). However, because snakes are a monophyletic group arising from within a group of lizards, the taxon Serpentes and its definition delimit a monophyletic group. Herein, the term lizard represents our shared perception and excludes Serpentes and Amphisbaenia.
Lizards are a very large and widespread group of the reptilian order Squamata. The nearly 7200 species of lizards are the most diverse and speciose living clade of reptiles; of course this total includes the worm lizards and snakes (which are actually reduced-limbed or limbless lizards). However, because snakes are a monophyletic group arising from within a group of lizards, the taxon Serpentes and its definition delimit a monophyletic group. Herein, the term lizard represents our shared perception and excludes Serpentes and Amphisbaenia.
The tuatara is a reptile endemic to New Zealand which, though it resembles most lizards, is actually part of a distinct lineage, order Sphenodontia. Lizards and snakes share a movable quadrate bone, distinguishing them from the sphenodonts which have a more primitive and solid diapsid skull.
==Common species==
==Common species==