Lepidosauria
The Lepidosauria (/ˌlɛpɪdoʊˈsɔːriə/, from Greek meaning scaled lizards) is a subclass or superorder of reptiles, containing the orders Squamata and Rhynchocephalia. Squamata includes lizards and snakes. Squamata contains over 9,000 species, making it by far the most species-rich and diverse order of non-avian reptiles in the present day. Rhynchocephalia was a formerly widespread and diverse group of reptiles in the Mesozoic Era. However, it is represented by only one living species: the tuatara (Sphenodon punctatus), a superficially lizard-like reptile native to New Zealand.
| Lepidosaurs | |
|---|---|
| Collage of five lepidosaurs. Clockwise from top left: tuatara, black mamba, green iguana, Smaug breyeri and reticulated python | |
| Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Lepidosauromorpha |
| Superorder: | Lepidosauria Haeckel, 1866 |
| Orders | |
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Lepidosauria is a monophyletic group (i.e. a clade), containing all descendants of the last common ancestor of squamates and rhynchocephalians. Lepidosaurs can be distinguished from other reptiles via several traits, such as large keratinous scales which may overlap one another. Purely in the context of modern taxa, Lepidosauria can be considered the sister taxon to Archosauria, which includes Aves (birds) and Crocodilia. Testudines (turtles) may be related to lepidosaurs or to archosaurs, but no consensus has been reached on this subject. Lepidosauria is encompassed by Lepidosauromorpha, a broader group defined as all reptiles (living or extinct) closer to lepidosaurs than to archosaurs.