The western long-tailed brush lizard (''Urosaurus graciosus'') is a species of

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 ...

in the family Phrynosomatidae. The species is native to the southwestern United States and adjacent northern Mexico.

Habitat and geographic range

''U. graciosus'' occurs in the Mojave Desert and the northwestern Sonoran Desert in the U.S. states of California, Arizona and Nevada, and in the Mexican states of Baja California and

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is d ...

Common name

This species received its

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

, long-tailed brush lizard, due to its tail, which is more than twice the body length, and due to its almost always being encountered on a tree or

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

Behavior

The long-tailed brush lizard's gray or tan coloration keeps it well camouflaged against branches while it waits for insects. Unlike most other phrynosomatid lizards, which bury in the sand at night during warm weather, ''U. graciosus'' spends the night on the tips of branches.

Identification

''U. graciosus'' is distinguishable from its close relative the tree lizard, ''

Urosaurus ornatus ''Urosaurus ornatus'', commonly known as the ornate tree lizard, is a species of lizard in the family Phrynosomatidae. The species is native to the southwestern United States and northwestern Mexico. The species, which was formerly called sim ...

'', by the presence of a tail more than two times its snout-vent length and the absence of a series of smaller scales running down the middle of the band of enlarged dorsal scales. ''U. graciosus'' is distinguishable from the black-tailed brush lizard, ''

Urosaurus nigricauda ''Urosaurus nigricauda'' is a species of lizard. Common names for this species include the Baja California brush lizard, black-tailed brush lizard, and small-scaled tree lizard. Its range includes southern California, Baja California Baja Cal ...

'', by the presence of a tail more than two times its snout-vent length and relatively large dorsal scales transitioning abruptly into granular lateral scales (in ''U. nigricauda'', the dorsal scales are only slightly enlarged and transition gradually into the granular lateral scales). It is distinguishable from all other brush lizards ('' Urosaurus'') by geography.

Reproduction

''U. graciosus'' is

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

Subspecies

Two

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

are recognized as being valid, including the

nominotypical subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

. The Reptile Database. www.reptile-database.org. *'' Urosaurus graciosus graciosus'' *'' Urosaurus graciosus shannoni''

Etymology

The subspecific name, ''shannoni'', is in honor of American herpetologist Frederick Albert Shannon.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . (''Urosaurus graciosus shannoni'', p. 241).

References

* Boulenger, George Albert (1885). ''Catalogue of the Lizards in the British Museum (Natural History). Second Edition. Volume II. Iguanidæ ...'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xiii + 497 pp. + Plates I-XXIV. (''Uta gratiosa'', p. 213). * Hallowell, Edward (1854). "Descriptions of new Reptiles from California". ''Proceedings of the Academy of Natural Sciences of Philadelphia'' 7: 91–97. (''Urosaurus graciosus'', new species, pp. 92–93). * Lowe, Charles H., Jr. (1955). "A New Subspecies of ''Urosaurus graciosus'' Hallowell with a Discussion of Relationships Within and of the genus ''Urosaurus'' ". ''Herpetologica'' 11 (2): 96–101. (''Urosaurus graciosus shannoni'', new subspecies). * Mittleman, M. B. (1942). "A Summary of the Iguanid Genus ''Urosaurus'' ". ''Bulletin of the Museum of Comparative Zoölogy at Harvard College'' 91 (1): 105–181 + Plates 1–16. (''Urosaurus ornatus graciosus'', pp. 144–145 + Plate 7). *Reeder, Tod W.; Wiens, John J. (1996). "Evolution of the Lizard Family Phrynosomatidae as Inferred from Diverse Types of Data". ''Herpetological Monographs'' 10: 43-84. * Stebbins, Robert C. (2003). ''A Field Guide to Western Reptiles and Amphibians, Third Edition''. The Peterson Field Guide Series ®. Boston and New York: Houghton Mifflin Company. 533 pp., 56 color plates. . (''Urosaurus graciosus'', pp. 295–296 + Plate 32 + Map 97). *Wiens, John J. (1993). "Phylogenetic Systematics of the Tree Lizards (Genus ''Urosaurus'')". ''Herpetologica'' 49 (4): 399-420. {{Taxonbar, from=Q3004433 Urosaurus Fauna of the Colorado Desert Fauna of the Mojave Desert Fauna of the Sonoran Desert Reptiles of Mexico Reptiles of the United States Reptiles described in 1854 Taxa named by Edward Hallowell (herpetologist)