[3] Described as a distinct species by John Edward Gray in 1839 (being named after Henri Marie Ducrotay de Blainville), it was later reclassified as a subspecies of the coast horned lizard (P. coronatum) in 1933.

[8] Harvester ants require dry conditions and therefore struggle in cultivated urban ecosystems with irrigated lawns, which in turn impacts horned lizard populations.

[12] The San Diego horned lizard is no longer present in many sections of Southern California due to urbanization, and other types of habitat loss.

[10] The population of horned lizards are declining because of habitat loss or degradation, hunting or capturing by humans and an increase of invasive species of Argentine ants.

[14] These lizards are vulnerable to a wide range of predators such as Badgers, Foxes, Coyotes, house pets, Greater Roadrunner, Loggerhead Shrike, American Kestrel, Burrowing Owl, and the Northern Pacific Rattlesnake.