Description: A long (up to about 4.2 inches snout-vent length), slender lizard with a tail longer than the body. The largest reported size for this all-female species is 4.2 inches snout-vent length. Range of snout-vent lengths of hatchlings was 1.5 to 2.1 inches. Body covered with granular scales; dark background color with six light, longitudinal stripes running the length of the body; light dorsal bars and spots result in a checkered pattern. Ventral scales large and somewhat rectangular; enlarged scales anterior to the gular fold.

Lizards have a dark background color with six light, longitudinal stripes running the length of the body; light bars and spots result in a checkered pattern. There are four described pattern-classes which are generally allopatri. Although the longitudinal stripes are prominent on the dorsal surface of hatchling lizards, the few dorsal spots are usually in the mid-dorsal area. During development, the amount of spotting and appearance of bars increases. Many hatchlings have a blue to blue-gray tail, with the color becoming more subdued as the lizard grows.

Often difficult to differentiate in the field from the diploid, parthenogenetic Aspidoscelis tesselatus (Common Checkered Whiptail) in areas of sympatry: Many, but not all, individuals of A. neotesselatus have an irregular light streak or stripe on the rear of the thigh (absent on A. tesselatus); the base of the tail has more apparent extension of the dorsolateral lines and vertebral fields for A. neotesselatus (more scattered appearance in A. tesselatus).

Habitat: Includes canyons, the vicinity of hillsides, rivers, arroyos, and creeks, as well as heavily altered habitats with slopes. This lizard often is encountered in areas of Ponderosa pine, Gambel’s oak, pinyon-juniper woodland, and shrublands and grasslands with rabbitbrush, cholla, and yucca.

Range: The native range of the Colorado Checkered Whiptail is restricted to the Arkansas River drainage of southeastern Colorado (see below), but established arrays have been reported in Grant County, Washington, and Denver and Adams counties, Colorado

Found in these States: CO

Diet: Colorado Checkered Whiptails forage opportunistically, and the most common food items for adults are grasshoppers and termites, while spiders and leafhoppers were the primary food items for young lizards.

Reproduction: This lizard is an all-female, parthenogenetic species.

Status: Listed as Near Threatened because its extent of occurrence is less than 20,000 km², extent and quality of habitat are undergoing decline, and if such declines continue the distribution might become severely fragmented (which it is probably not at the moment). Hence almost qualifies as threatened under criterion B1ab(iii). However, this parthenogenetic species has good reproductive potential, tolerates moderate levels of habitat alteration, and might be able to persist in relatively small patches of suitable habitat.

Taxonomy: