The crevice spiny lizard (Sceloporus poinsettii) is a species of small, phrynosomatid lizard. The epithet, poinsettii, is in honor of American physician, botanist, and statesman, Joel Roberts Poinsett.
It is endemic to the Chihuahuan Desert, in the US states of Texas and New Mexico, and in the Mexican states of Chihuahua, Coahuila, Durango.
The crevice spiny lizard is typically grey in color, but sometimes can have a ruddy red-brown appearance with a black and white collar around the neck region. The underside is typically light grey, but males often have blue patches on either side of their bellies. The tail typically has black banding. Their scales have a distinctly spiny texture. They can grow to 11.8 cm (4.6 in) snout-to-vent length, and 31.1 cm (12.2 inches) total length.
Crevice spiny lizards are typically shy and nervous, fleeing up a rock face or into a crevice if approached. They prefer semi-arid habitats, often of limestone rock, where there are numerous holes and easily accessible cracks.
They are insectivorous, consuming a wide variety of spiders, beetles, and other insects, but they will sometimes also consume tender vegetation.
They are one of the several species of Sceloporus that are ovoviviparous. Breeding occurs in the spring, and a litter of up to 11 young are born in midsummer.