Aspidoscelis tigris

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.

Some authors regarded Aspidoscelis tigris marmorata as a distinct species (Hendricks and Dixon 1986). Molecular and morphological data from "hybrid" (secondary contact) zones in New Mexico indicate that random nonassortative mating prevails, with no selection agaianst hybrids; marmorata should be treated as a subspecies of A. tigris (Dessauer and Cole 1991). However, Crother et al. (2000) and de Queiroz and Reeder (in Crother 2008) interpreted this evidence differently and listed A. tigris and A. marmorata as "incompletely separated species." Stebbins (2003) maintained marmorata as a subspecies of A. tigris.

Annual hybridization between parthenogenetic A. tesselata and bisexual A. tigris marmorata 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 and Walker (1991) for morphological evidence for the conspecific relationship of subspecies aethiops and gracilis. See Taylor et al. (1994) for documentation of a broad zone of intergradation between subspecies tigris and gracilis in southwestern Arizona; despite the broad zone of intergradation, the authors concluded that these taxa warrant recognition as distinct subspecies because they are phenotypically distinctive across most of their ranges. See Taylor and Walker (Copeia 1996:140-148) for information on the proper relegation of the names C. t. gracilis, C. t. dickersoni, C. t. disparilis, and C. t. punctilinealis (the last is regarded as a provisional name for populations presently allocated to C. t. gracilis).

See Taylor and Buschman (1993) for information on geographic variation in morphology in subspecies septentrionalis.

The range extends from Oregon and Idaho to southern Baja California, Sinaloa, and southern Coahuila; west to California, east to Colorado and Texas (Stebbins 2003). This includes the range of the marbled whiptail (Aspidoscelis tigris marmorata), which some list as a distinct (but "incompletely separated") species.

Subspecies marmoratus (regarded as a distinct species by some authorities): southern New Mexico and southern and western Texas south through eastern Chihuahua and southern Coahuila.

This species is represented by hundreds of occurrences or subpopulations.

No major threats have been identified.