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==Taxonomy==
 
==Taxonomy==
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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.  
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Reptiles are ectothermic vertebrates with scales or plates, right and left aortic arches, a partially divided heart and a single occipital condyle.  
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Lizards are members 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 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. The lizards and their snake descendants are the only living squamates.
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Excluding the snakes, lizards are still the most speciose extant reptiles, with about 4450 species.  
    
==Common species==
 
==Common species==
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