View source for Aspidoscelis

{{Short description|Genus of lizards}}
{{Automatic taxobox
| image = California Whiptail (Aspidoscelis tigris).JPG
| image_caption  = [[Western whiptail|California whiptail]] ''(Aspidoscelis tigris munda)''
| taxon = Aspidoscelis
| authority = [[Leopold Fitzinger|Fitzinger]], 1843
| subdivision_ranks = Species
| subdivision = Over 40, see text.<ref name="EOL">Genus ''Aspidoscelis'' at Encyclopedia of Life. [http://www.eol.org/search?q=Aspidoscelis&search_image=Submit&cx=005034203190629281476%3Adcs9wj9m5c4&cof=FORID%3A11&ie=UTF-8&search_type=text eol.org]</ref>
}}

'''''Aspidoscelis''''' is a [[genus]] of [[whiptail lizard]]s in the [[Family (biology)|family]] [[Teiidae]].

==Taxonomy==
The [[Binomial nomenclature|nomenclature]] for the genus ''Aspidoscelis'' was published by [[species:Tod W. Reeder|T.W. Reeder]] et al. in 2002. Many [[species]] that were formerly included in the genus ''[[Cnemidophorus]]'' are now considered ''Aspidoscelis'' based upon divergent characters between the two groups.

==Etymology==
The name ''Aspidoscelis'' literally means "shield-leg", from the Ancient Greek [[wikt:ἀσπίς|{{transliteration|grc|aspido-|nocat=yes}}]] ("shield") and [[wikt:σκέλος|{{transliteration|grc|skelos|nocat=yes}}]] ("leg").<ref>{{cite web|title=''Aspidoscelis sexlineata''|url=http://wwx.inhs.illinois.edu/collections/herps/data/ilspecies/cn_sexline/|website=Illinois Natural History Survey|publisher=University of Illinois|quote=Etymology: ''Aspidoscelis'' - aspido (Greek) shield; -skelos (Greek) meaning leg|access-date=2015-11-14|archive-date=2016-05-18|archive-url=https://web.archive.org/web/20160518095833/http://wwx.inhs.illinois.edu/collections/herps/data/ilspecies/cn_sexline}}</ref>

==Species==
The following species are recognized as being valid.<ref name="EOL"/><ref>{{EMBL genus|genus=Aspidocelis}}. www.reptile-database.org.</ref>

*''[[Aspidoscelis angusticeps]]'' {{small|([[Edward Drinker Cope|Cope]], 1878)}} – Yucatán whiptail
*''[[Aspidoscelis arizonae]]'' {{small|([[John Van Denburgh|Van Denburgh]], 1896)}} – Arizona striped whiptail
*''[[Aspidoscelis burti]]'' {{small|([[Edward Harrison Taylor|E.H. Taylor]], 1938)}} – canyon spotted whiptail
*''[[Aspidoscelis calidipes]]'' {{small|([[species:William Edward Duellman|Duellman]], 1955)}} – Tepalcatepec Valley whiptail
*''[[Aspidoscelis carmenensis]]'' {{small|([[species:Thomas Paul Maslin Jr.|Maslin]] & [[species:Diane M. Secoy|Secoy]], 1986)}} – Carmen Island whiptail
*''[[Aspidoscelis ceralbensis]]'' {{small|(Van Denburgh & [[Joseph Richard Slevin|Slevin]], 1921)}} – Cerralvo Island whiptail
*''[[Aspidoscelis communis]]'' {{small|(Cope, 1878)}} – Colima giant whiptail
*''[[Aspidoscelis costatus]]'' {{small|(Cope, 1878)}} – western Mexico whiptail lizard
*''[[Aspidoscelis cozumela]]'' {{small|([[Hans Friedrich Gadow|Gadow]], 1906)}} – Cozumel racerunner
*''[[Aspidoscelis danheimae]]'' {{small|([[species:Charles Earle Burt|Burt]], 1929)}} – Isla San José whiptail
*''[[Aspidoscelis deppii]]'' {{small|([[Arend Friedrich August Wiegmann|Wiegmann]], 1834)}} – blackbelly racerunner
*''[[Aspidoscelis dixoni]]'' {{small|([[species:James F. Scudday|Scudday]], 1973)}} – gray checkered whiptail
*''[[Aspidoscelis espiritensis]]'' {{small|(Van Denburgh & Slevin, 1921)}} – Espiritu Santo whiptail
*''[[Aspidoscelis exsanguis]]'' {{small|([[Charles Herbert Lowe|Lowe]], 1956)}} – Chihuahuan spotted whiptail
*''[[Aspidoscelis franciscensis]]'' {{small|(Van Denburgh & Slevin, 1921)}} – San Francisco Island whiptail
*''[[Aspidoscelis gularis]]'' {{small|([[Spencer Fullerton Baird|Baird]] & [[Charles Frédéric Girard|Girard]], 1852)}} – Texas spotted whiptail
*''[[Aspidoscelis guttatus]]'' {{small|(Wiegmann, 1834)}} – Mexican racerunner
*''[[Aspidoscelis hyperythrus]]'' {{small|(Cope, 1864)}} – orange-throated whiptail
*''[[Aspidoscelis inornatus]]'' {{small|(Baird, 1859)}} – little striped whiptail
*''[[Aspidoscelis labialis]]'' {{small|([[Leonhard Stejneger|Stejneger]], 1890)}} – Baja California whiptail
*''[[Aspidoscelis laredoensis]]'' {{small|([[species:Charles O. McKinney|McKinney]], [[species:Fenton R. Kay|Kay]] & [[species:Robert A. Anderson|R. Anderson]], 1973)}} – Laredo striped whiptail
*''[[Aspidoscelis lineattissimus]]'' {{small|(Cope, 1878)}} – many-lined whiptail
*''[[Aspidoscelis marmoratus]]'' {{small|(Baird & Girard, 1852)}} – marbled whiptail
*''[[Aspidoscelis martyris]]'' {{small|([[Leonhard Stejneger|Stejneger]], 1891)}} – San Pedro Martir whiptail
*''[[Aspidoscelis maslini]]'' {{small|([[species:Thomas H. Fritts|Fritts]], 1969)}} – Maslin's whiptail
*''[[Aspidoscelis maximus]]'' {{small|(Cope, 1864)}} – Cape Region whiptail
*''[[Aspidoscelis mexicanus]]'' {{small|([[Wilhelm Peters|W. Peters]], 1869)}} – Mexican whiptail
*''[[Aspidoscelis motaguae]]'' {{small|([[species:J. Townsend Sackett|Sackett]], 1941)}} – giant whiptail
*''[[Aspidoscelis neomexicanus]]'' {{small|(Lowe & [[Richard G. Zweifel|Zweifel]], 1952)}} – New Mexico whiptail
*''[[Aspidoscelis neotesselatus]]'' {{small|([[species:James Martin Walker|Walker]], [[species:James E. Cordes|Cordes]] & [[species:Harry L. Taylor|H.L. Taylor]], 1997)}} – Colorado checkered whiptail, triploid checkered whiptail
*''[[Aspidoscelis opatae]]'' {{small|([[species:John W. Wright|Wright]], 1967)}} – Opata whiptail
*''[[Aspidoscelis pai]]'' {{small|(Wright & Lowe, 1993)}} – Pai striped whiptail
*''[[Aspidoscelis parvisocius]]'' {{small|(Zweifel, 1960)}} – Mexican pigmy whiptail
*''[[Aspidoscelis pictus]]'' {{small|(Van Denburgh & Slevin, 1921)}} – Isla Monserrate whiptail
*''[[Aspidoscelis preopatae]]'' {{small|[[species:Anthony J. Barley|Barley]], [[species:Tod W. Reeder|Reeder]], [[species:Adrián Nieto-Montes de Oca|Nieto-Montes de Oca]], [[species:Charles J. Cole|Cole]] & [[species:Robert C. Thomson|Thomson]], 2021}}
*''[[Aspidoscelis rodecki]]'' {{small|([[species:Clarence John McCoy|C.J. McCoy]] & Maslin, 1962)}} – Rodeck's whiptail
*''[[Aspidoscelis sackii]]'' {{small|(Wiegmann, 1834)}} – Sack's spotted whiptail
*''[[Aspidoscelis scalaris]]'' {{small|(Cope, 1892)}} – rusty-rumped whiptail
*''[[Aspidoscelis septemvittatus]]'' {{small|(Cope, 1892)}} – plateau spotted whiptail
*''[[Aspidoscelis sexlineatus]]'' {{small|([[Carl Linnaeus|Linnaeus]], 1766)}} – six-lined racerunner
*''[[Aspidoscelis sonorae]]'' {{small|(Lowe & Wright, 1964)}} – Sonoran spotted whiptail
*''[[Aspidoscelis stictogrammus]]'' {{small|([[species:William Leslie Burger|Burger]], 1950)}} – giant spotted whiptail 
*''[[Aspidoscelis tesselatus]]'' {{small|([[Thomas Say|Say]], 1823)}} – common checkered whiptail
*''[[Aspidoscelis tigris]]'' {{small|(Baird & Girard, 1852)}} – western whiptail
*''[[Aspidoscelis uniparens]]'' {{small|(Wright & Lowe, 1965)}} – desert grassland whiptail lizard
*''[[Aspidoscelis velox]]'' {{small|([[Stewart Springer|Springer]], 1928)}} – plateau striped whiptail
*''[[Aspidoscelis xanthonotus]]'' {{small|(Duellman & Lowe, 1953)}} – red-backed whiptail

''[[Nota bene]]'': A [[Binomial nomenclature|binomial authority]] in parentheses indicates that the species was originally described in a genus other than ''Aspidoscelis''.

==Speciation==
In 2011, it was announced that a [[Parthenogenesis|parthenogenetic]] hybrid ''Aspidocelis'' was bred in the laboratory.<ref>{{cite journal|title=Laboratory synthesis of an independently reproducing vertebrate species|author1=Lutes, Aracely A.|author2=Baumann, Diana P.|author3=Neaves, William B.|author4=Baumann, Peter|journal=Proceedings of the National Academy of Sciences|volume=108|issue=24|pages=9910–9915|date=2011|doi=10.1073/pnas.1102811108|doi-access=free|pmid=21543715 |pmc=3116429}}</ref> This serves as a demonstration of how other hybrid parthenogens in this genus may have arisen.

== Parthenogenesis and unisexual species ==
Thirteen species within Aspidoscelis are unisexual, consisting entirely of females that reproduce through parthenogenesis—cloning unfertilized eggs to produce genetically identical offspring.These species originated through hybridization between divergent bisexual ancestral species, with the transition to asexual reproduction occurring in a single generation. This represents the largest group of unisexual vertebrate species known to science.<ref name=":0">{{Cite journal |last=Barley |first=Anthony J |last2=Cole |first2=Charles J |date=2025 |title=Speciation by hybridization: the mind-boggling nature, educational, and research value of the largest group of unisexual vertebrates |url=https://academic.oup.com/bioscience/article/75/4/331/8015366 |journal=BioScience |language=en |volume=75 |issue=4 |pages=331–341 |doi=10.1093/biosci/biaf010 |issn=0006-3568 |pmc=12016801 |pmid=40276476}}</ref>

The unisexual species exhibit varying chromosome numbers reflecting their hybrid origins. Diploid species formed through "primary hybrid speciation" when first-generation female hybrids of two distinct bisexual species began reproducing parthenogenetically. Triploid and tetraploid species arose through "genome addition," when cloned eggs of unisexual females were fertilized by males of bisexual species, resulting in offspring with additional chromosome sets.<ref name=":0" />

This hybridization seesm separated by 15–25 million years of evolution. The parental species combinations have been determined through karyotypic, allozyme, and mitochondrial DNA studies. Early chromosome studies in the 1960s first revealed abnormal chromosome numbers in some unisexual species, indicating genome combinations from divergent species through hybridization.<ref name=":0" />

The unisexual species occur in two main geographic regions: the southwestern United States and northern Mexico, and southern Mexico with eastern Guatemala and Belize. Recent cellular research has revealed that chromosome number and genetic diversity are maintained across generations because identical, duplicated chromosomes pair during meiosis rather than homologous chromosomes.<ref name=":0" />

==References==
{{Reflist}}

==Further reading==
*[[Leopold Fitzinger|Fitzinger L]] (1843). ''Systema Reptilium, Fasciculus Primus, Amblyglossae.'' Vienna: Braumüller & Seidel. 106 pp. + indices. (''Aspidoscelis'', new genus, p.&nbsp;20). (in Latin).

==External links==
*[[species:Tod W. Reeder|Reeder, Tod W.]]; [[species:Charles James Cole|Cole, Charles J.]]; [[Herbert C. Dessauer|Dessauer, Herbert C.]] (2002). "Phylogenetic relationships of whiptail lizards of the genus ''Cnemidophorus'' (Squamata, Teiidae) : a test of monophyly, reevaluation of karyotypic evolution, and review of hybrid origins". ''American Museum Novitates'' (3365): 1-61. [http://hdl.handle.net/2246/2854]


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[[Category:Aspidoscelis| ]]
[[Category:Lizard genera]]
[[Category:Taxa named by Leopold Fitzinger]]

{{Teiidae-stub}}