Description: 2.0 to 2.8 inches long from snout to vent. A small flat-bodied lizard with a flattened head, soft skin with fine granular scales, a long thin tail, lidless eyes with vertical pupils, and gular folds. Similar to and closely related to Xantusia henshawi, but with a narrower head, a body that is shorter between the limbs, and with thinner limbs. The color is white to yellowish, with large dark brown spots on the upper surfaces, and irregular spots and bands on the tail. This species does not exhibit the light and dark phases seen in X. henshawi. It looks more like the light phase of that species but with more light coloring and smaller dark spots. The underside is white with minute black speckling only on the forepart. Males have enlarged femoral pores.

Habitat: Inhabits a very small area of sandstone and mudstone.

Range: Endemic to California. Occurs only in the Truckhaven Rocks area of San Diego County, in Anza-Borrego State Park. From 790 to 1,000 ft.

Found in these States: CA

Diet: Diet is not well known but probably is similar to that of X. henshawi, consisting of small invertebrates such as ants, beetles, and bees.

Reproduction: Reproduction is not well known but breeding probably occurs in May and June with live young born in September.

Status: Listed as Vulnerable because it is known from only a single location. Protected from collection by the state and the federal government and by the fact that its known range falls completely within the boundaries of Anza-Borrego State Park where it is also protected.

Taxonomy: In 1986 Grismer and Galvan published the first description of this species, classifying it a subspecies of Xantusia henshawi - Xantusia henshawi gracilis - Sandstone Night Lizard. It was elevated to a full species in 2001.