''Xantusia'' () is one of three

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

of night lizards (

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Xantusiidae).

Species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of ''Xantusia'' are small to medium-sized, viviparous (live-bearing)

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

s found in the

U.S. The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...

Southwest The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A '' compass rose'' is primarily composed of four cardinal directions—north, east, south, and west— ...

and in northern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. These lizards display morphological adaptations to specific microhabitats. They occupy rock crevices and decaying plants. Rock dwellers generally have brighter coloration, longer limbs and digits, and larger size than plant dwellers, which are generally duller, smaller, and have shorter limbs.
Species of the genus ''Xantusia'' are remarkably disjunct, with populations scattered throughout the deserts and mountains of the far western borderlands with only a handful of recorded cases of interspecific allopatry. The genus contains at least seven distinct cases of morphological convergence to the rock dwelling ecomorph in Arizona, California, Baja California, and Central Mexico.

Taxonomy and etymology

The names and descriptions of the genus ''Xantusia'' and the type species ''X. vigilis'' were published in 1859 by

Spencer Fullerton Baird Spencer Fullerton Baird (; February 3, 1823 – August 19, 1887) was an American naturalist, ornithologist, ichthyologist, Herpetology, herpetologist, and museum curator. Baird was the first curator to be named at the Smithsonian Institution. He ...

, the generic name commemorating the

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

John Xantus.
Based on the most current phylogenetic analyses of Xantusiid lizards, The earliest-diverging species of the genus is ''Xantusia riversiana''. Sister to this species are two clades: the ''X. vigilis'' species complex, and the southern ''Xantusia''. The ''X. vigilis'' species complex is made up of ''X. vigilis'', ''X. arizonae'', ''X. sierrae'', ''X. bezyi'', ''X. wigginsi'', and its most recent addition ''X. jaycolei''. Leavitt DH, Bezy RL, Crandall KA, Sites JW Jr (2007). "Multi locus DNA sequence data reveal a history of deep cryptic vicariance and habitat driven convergence in the desert night lizard ''Xantusia vigilis'' species complex (Squamata: Xantusiidae)". ''Molecular Ecology'' 16 (21): 4455–4481. The Southern ''Xantusia'' contains ''X. gilberti'', ''X. sherbrookii'', ''X. gracilis'', ''X. henshawi'', ''X. bolsonae'', ''X. extorris'', and ''X. sanchezi''.

Species

The following is a list of species in the genus. *'' Xantusia arizonae'' Klauber, 1931 –

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

night lizard *'' Xantusia bezyi'' Papenfuss, Macey & J.A. Schulte, 2001 – Bezy's night lizard *'' Xantusia bolsonae'' Webb, 1970 – bolsón night lizard *'' Xantusia extorris'' Webb, 1965 –

Durango Durango, officially the Free and Sovereign State of Durango, is one of the 31 states which make up the Political divisions of Mexico, 32 Federal Entities of Mexico, situated in the northwest portion of the country. With a population of 1,832,650 ...

night lizard *'' Xantusia gilberti'' Van Denburgh, 1895 – Gilbert's night lizard *'' Xantusia gracilis'' Grismer & Galvan, 1986 – sandstone night lizard *'' Xantusia henshawi'' Stejneger, 1893 – granite night lizard *''

Xantusia jaycolei ''Xantusia jaycolei'' is a species of lizard in the Family (biology), family Xantusiidae. The species is native to Mexico specifically inhabiting the rugged and biodiverse regions of the country. Etymology The Specific name (zoology), specific na ...

'' R. Bezy, K. Bezy & Bolles, 2008 *'' Xantusia riversiana''

Cope A cope ( ("rain coat") or ("cape")) is a liturgical long mantle or cloak, open at the front and fastened at the breast with a band or clasp. It may be of any liturgical colour. A cope may be worn by any rank of the Catholic or Anglican clerg ...

, 1883 – island night lizard *'' Xantusia sanchezi'' R. Bezy & Flores-Villela, 1999 – Sanchez's night lizard *'' Xantusia sherbrookei'' R. Bezy, K. Bezy & Bolles, 2008 *''

Xantusia sierrae ''Xantusia sierrae'', the Sierra night lizard, is a species of lizard in the family Xantusiidae. It is a small lizard found in California California () is a U.S. state, state in the Western United States that lies on the West Coast of th ...

'' R. Bezy, 1967 – sierra night lizard *'' Xantusia vigilis'' Baird, 1859 – desert night lizard *'' Xantusia wigginsi'' Savage, 1952 – Wiggins's desert night lizard

Taxonomy and etymology

Species

References

Further reading