Xantusia

Xantusia () is one of three genera of night lizards (family Xantusiidae). Species of Xantusia are small to medium-sized, viviparous (live-bearing) lizards found in the U.S. Southwest and in northern Mexico. These lizards display morphological adaptations to specific microhabitats. They occupy rock crevices and decaying plants. Rock dwellers generally have brighter coloration, longer limbs and digits, and larger size than plant dwellers, which are generally duller, smaller, and have shorter limbs. Species of the genus Xantusia are remarkably disjunct, with populations scattered throughout the deserts and mountains of the far western borderlands with only a handful of recorded cases of interspecific allopatry. The genus contains at least seven distinct cases of morphological convergence to the rock dwelling ecomorph in Arizona, California, Baja California, and Central Mexico.