Xenosauridae is a family of anguimorph

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

s whose only living representative is the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Xenosaurus ''Xenosaurus'' is a genus of lizards. ''Xenosaurus'' is the only extant genus in the family Xenosauridae with 13 species currently recognized."Xenosauridae" and "''Xenosaurus'' ". The Reptile Database. www.reptile-database.org. Also known as the ...

'', which is native to Central America. Xenosauridae also includes the extinct genera '' Exostinus'' and '' Restes''. Also known as knob-scaled lizards, they have rounded, bumpy scales and

osteoderm Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amp ...

s. Most living species prefer humid, rocky habitats, although they are widespread within their native regions, with some inhabiting semi-arid scrub environments. They are carnivorous or insectivorous, and give birth to live young. ''

Shinisaurus The Chinese crocodile lizard (''Shinisaurus crocodilurus'') is a semiaquatic anguimorph lizard found only in cool forests in southeast China and northeast Vietnam. The Chinese crocodile lizard spends much of its time in shallow water or in overha ...

'', the Chinese crocodile lizard, was once also regarded as a member of Xenosauridae, but most recent studies of the evolutionary relationships of anguimorphs consider ''Shinisaurus'' to be more closely related to

monitor lizard Monitor lizards are lizards in the genus ''Varanus,'' the only extant genus in the family Varanidae. They are native to Africa, Asia, and Oceania, and one species is also found in the Americas as an invasive species. About 80 species are recogn ...

s and helodermatids than to ''Xenosaurus''. Xenosauridae is part of a larger

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

or evolutionary grouping called

Carusioidea Carusioidea is a clade of lizards that includes the family Xenosauridae (knob-scaled lizards) from Central America and the extinct genus '' Carusia'' from the Late Cretaceous of Mongolia. It was named in 1998 after a sister-group relationship wa ...

, which, in addition to xenosaurids, includes the extinct genus ''

Carusia ''Carusia'' is an extinct genus of lizards from the Late Cretaceous of Mongolia. It is a close relative of the family Xenosauridae, which includes living knob-scaled lizards. Fossils of the type and only species ''Carusia intermedia'' come from ...

''.

References

External links

xenosauridae
Lizard families Taxa named by Edward Drinker Cope Extant Barremian first appearances {{lizard-stub es:Xenosauridae fr:Xenosauridae