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Squamata (lizards, snakes; class Reptilia, subclass Lepidosauria) A highly successful order which includes 95% of all living reptiles. The lizards and snakes are each given ordinal status in some classifications. The earliest lizards had appeared by the Triassic and the snakes, which might be regarded as ‘legless’ lizards, diverged from the ancestral line in the Cretaceous. The skull has lost the lower temporal arch, allowing mobility of the quadrate and increased gape. The tongue is notched or forked. Body scales are generally small and overlapping. Limblessness is common. They are divided into two suborders (or orders), Sauria (Lacertilia) and Serpentes (Ophidia).

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Squamata An order of reptiles comprising the lizards and snakes. They appeared at the end of the Triassic period, about 170 million years ago, and have invaded a wide variety of habitats. Most lizards have four legs and a long tail, eardrums, and movable eyelids. Snakes are limbless reptiles that lack eardrums; the eyes are covered by transparent immovable eyelids and the articulation of the jaws is very loose, enabling a wide gape to facilitate swallowing prey whole.