Phrynosoma blainvillii Gray, 1839

Common Name & Body Shape

Phrynosoma blainvillii, commonly called the San Diego horned lizard or Blainville's horned lizard, is a flat-bodied lizard. It has long spiky horns on the top and sides of its head, and smaller spikes covering its body and tail.

Adult Size

Adult lizards measure 2.5 to 4.5 inches (6.4 to 11.4 cm) from the tip of the snout to the base of the tail, just before the tail begins.

Base Coloration

Their base color can be red, brown, yellow, or gray, with several black spots on the back and neck. While dorsal coloration varies widely between individuals, it typically matches the color of the local prevailing soil.

Sexual Dimorphism

Females are larger than males; males have larger horns at the base of the tail and visible pores on the inside of their hind legs.

Geographic Range

This species occurs from California's Central Valley south through Southern California to northern Baja California.

Habitat Preferences

It is most often found near mountains in areas with sandy ground, sparse low vegetation, and proximity to ant hills.

Elevation Range

Confirmed populations have been recorded at elevations from 10 m (33 ft) above sea level at El Segundo Dunes, Los Angeles County, up to around 2,130 m (6,990 ft) above sea level at Tahquitz Meadow, Riverside County.

Reproductive Season

In Southern California, the reproductive season of the San Diego horned lizard runs from early March to June.

Egg Laying & Hatching

Each female lays between 6 and 21 eggs per year, which hatch a few months after being laid, between August and September. Females lay their eggs in the Santa Monica and Simi Hills area.