Description: There are several important characteristics that can be used to identify desert horned lizards from other horned lizards. Horned lizards can be distinguished from other lizards by the large pointed scales that protrude from the back of their heads, giving them the appearance of having horns, as well as the flat and broad shape of their bodies.
This species of lizard has a distinctive flat body with one row of fringe scales down the sides. They are a medium sized lizard and can grow up to approximately 3.75 inches or 95mm in size. They have one row of slightly enlarged scales on each side of the throat. Colours can vary and generally blend in with the color of the surrounding soil, but they usually have a beige, tan, or reddish dorsum with contrasting, wavy blotches of darker color. They have two dark blotches on the neck that are very prominent and are bordered posteriorly by a light white or grey color. They also have scattered pointed scales and other irregular dark blotches along the dorsum of their body. Unlike other horned lizards, Phrynosoma platyrhinos individuals do not have a prominent dorsal stripe. Their dorsal stripe can appear faintly or be entirely absent depending on the individual. They also have pointed scales on the dorsum (back) of the body. Juveniles are similar to adults, but have shorter and less-pronounced cranial spines. Desert horned lizards have horns that are wide at the base, which isn't true for their congener, the short-horned lizard. Pictured to the left is Blainville's Horned Lizard (Phrynosoma blainvillii), note the colored horns and double row of fringed scales alongside the body. The desert horned lizards' horns also do not come into contact with one another at the base.
Habitat: Found in extremely diverse habitats. The flat-tailed horned lizard occurs in areas of fine sand, while the Pygmy Short-horned lizard (P. douglasii) is found in shortgrass prairie all the way up into spruce-fir forest. The most common species in the Arizona Upland subdivision is the Regal Horned lizard (P. solare), which frequents rocky or gravelly habitats of arid to semiarid plains, hills and lower mountain slopes. The desert horned lizard (P. platyrhinos) is found mostly in the Sonoran and Mojave deserts. It can be found in southeastern Oregon, California, western Arizona Utah, Idaho and Nevada. Outside of the United States it is found in Mexico, northwestern Sonora, and northeastern Baja California. They have a preference for places that they can find shrub covering with an understory. Phrynosoma platyrhinos will often bury themselves in sand soil, if possible, or they will live in burrows that were constructed by other animals.
Range: They typically range from southern Idaho in the north to northern Mexico in the south. These lizards can generally be found in areas with desert climates throughout western North America.
Diet: Desert horned lizards prey primarily on invertebrates, such as ants (including red harvester ants,) crickets, grasshoppers, beetles, worms, flies, ladybugs, meal worms and some plant material. They can often be found in the vicinity of ant hills, where they sit and wait for ants to pass by. Ants contain a large amount of chitin, an indigestible compound, this makes them not as nutrient rich, so larger amounts must be consumed to sustain Phrynosoma platyrhinos. As an evolutionary advantage desert horned lizards developed larger stomachs to allow them to consume larger concentrations of ants. When they find an area of soft sand, they usually shake themselves vigorously, throwing sand over their backs and leaving only their head exposed. This allows them to hide from predators and await their unsuspecting prey.
Reproduction: This lizard is an egg layer. Females bury eggs in the soil. In southern Nevada, egg deposition occurs April-July (apparently mainly early June). Clutch size averages about 7. Individual females produce one or two clutches per year. Incubation lasts about 50-60 days. Hatchlings appear from mid-July to August in southern Nevada, and as late as mid-September in some areas. Individuals become sexually mature in about 22 months.
Status: Listed as Least Concern in view of its wide distribution, large number of locations, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category.
Disclaimer: ITIS taxonomy is based on the latest scientific consensus available, and is provided as a general reference source for interested parties. However, it is not a legal authority for statutory or regulatory purposes. While every effort has been made to provide the most reliable and up-to-date information available, ultimate legal requirements with respect to species are contained in provisions of treaties to which the United States is a party, wildlife statutes, regulations, and any applicable notices that have been published in the Federal Register. For further information on U.S. legal requirements with respect to protected taxa, please contact the U.S. Fish and Wildlife Service.
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