Aspidoscelis tesselatus

This species has a complex nomenclatural history, and nomenclature remains unsettled. C. dixoni, C. tesselatus, and C. grahamii were regarded as conspecific by Price (1986) and Maslin and Secoy (1986). MtDNA data of Wright (1993) indicate that "C. dixoni and C. grahamii arose from separate hybridization events involving the same two parental species" (Degenhardt et al. 1996). Wright (1993) and Degenhardt et al. (1996) regarded C. C. dixoni and C. grahamii as separate species. Walker et al. (1994) rejected Wright's (1993) proposed nomenclatural changes and regarded C. grahamii as a synonym of C. tesselatus. Walker et al. (1995) determined that the purported undescribed triploid species of Densmore et al. (1989) and Wright (1993) has no reality. Walker et al. (1997) described the Coloradan triploid populations of C. tesselatus as a new species, C. neotesselatus (see taxonomic comments for that species).

Cordes and Walker (2006) presented evidence in the form of histocompatibility indicating that the origin of A. dixoni and at least one of the pattern classes of A. tesselata (E) form a single hybridization event, but they nonetheless treated these forms as different species on the basis of diagnosability (Crother 2008). de Quieroz and Reeder (in Crother 2012) cited the same research in treating A. dixoni as a synonym of A. tesselata, following the taxonomy used by Maslin and Secoy (1986).

Annual hybridization between parthenogenetic C. tesselatus and bisexual C. tigris marmoratus occurs in several locations in New Mexico and Texas, but this interaction does not appear to be resulting in the production of a new triploid parthenogenetic species (all examined female hybrids were sterile) (Taylor et al. 2001). See Taylor et al. (2003) for information on geographic variation in Chihuahua and New Mexico. Cole et al. (2007) presented evidence for hybridization between A. tesselata (one of the pattern classes formerly recognized as A. dixoni) and A. tigris punctilinealis and hypothesized that it may be negatively impacting the former taxon (Crother 2017).

Reeder et al. (2002) examined phylogenetic relationships of the whiptail lizards of the genus Cnemidophorus based on a combined analysis of mitochondrial DNA, morphology, and allozymes. They determined that Cnemidophorus in the traditional sense is paraphyletic and thus in need of nomenclatural revision. Rather than subsume all cnemidophorine species (including Kentropyx) in a single large genus (Ameiva), they proposed a split that placed the North American "Cnemidophorus" clade in the monophyletic genus Aspidoscelis; under this arrangement, South American taxa remain in the genus Cnemidophorus.

The range extends from southeastern Colorado (Hammerson 1999) through New Mexico (Degenhardt et al. 1996) and western Texas (Dixon 2000) to Chihuahua (Taylor et al. 2003). It also includes populations in very small areas of Texas and New Mexico that formerly were recognized as a separate species, A. dixoni (see Cordes and Walker 2006; de Quieroz and Reeder, in Crother 2012) . The distribution is mostly discontinuous and localized (Degenhardt et al. 1996, Bartlett and Bartlett 1999).

This species is represented by a large number of occurrences (e.g., see map in Degenhardt et al. 1996).

No major threats have been identified. Locally, populations have declined as a result of urbanization and conversion of habitat to agricultural uses (Walker et al. 1996; see Hammerson 1999).