California Reptiles & Amphibians

Phrynosoma (=Doliosaurus) platyrhinos platyrhinos -
Northern Desert Horned Lizard



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Range in California: Green

Red: Southern Desert Horned Lizard

Dot-locality Range Map




Adult, Modoc County
© William Flaxington
Adult, 4,000 ft., Washoe County, Nevada
Juvenile, Washoe County, Nevada
Adult, Washoe County, Nevada
Desert Horned Lizards have one row of fringe on the sides. Compare with the Coast Horned Lizard which has two.
 
Habitat, Washoe County, Nevada


Habitat, Modoc County
 
Description
Size
2.5 - 3.75 inches long from snout to vent (6.4 - 9.5 cm). (Stebbins 2003) Up to 5.5 inches including tail.
Appearance
A medium-sized flat-bodied lizard with a wide oval-shaped body and scattered enlarged pointed scales on the upper body and tail. The back skin is smooth with small spines. The snout is blunt. Horns extend from the back of the head, with the two central horns longest. There is one row of fringe scales on the sides of the body.

Color can be reddish, tan, dark gay, beige, brown and even black in areas with dark lava. Background coloring usually matches the local soil and rocks. A pair of large dark blotches mark the neck. Wavy dark blotches mark the back.
The belly is white with scattered small dark spots, smooth scales and black spotting at the vent opening.

Males are smaller than females, and have postanal scales, femoral pores, and a wider tail base. Juveniles appear similar to adults.
Behavior & Natural History
Diurnal. Adapted to hot and barren habitats. Remains underground during hot or cold weather. Hibernates in loose soil, usually emerging in April. Most active from April to July. Can be seen basking on rocks and road berms in the morning and late afternoon - early evening.

When threatened, this lizard is capable of running away quickly for only a short distance. It will often run under a low bush or into a rodent burrow to escape, or shuffle sideways to bury itself partly in the sand. Its main defense is remaining motionless using its cryptic coloring to blend into the background and make it difficult to see. It will crouch down low to prevent shadows that could make it easier to see, and sit still to avoid detection. When grabbed, it will inflate with air, hiss, threaten to bite, and move the head from side to side to jab with its horns. This species of horned lizard rarely defends itself by squirting blood from the corners of its eyes.

Although horned lizards may be desirable pets, captive animals normally do not live very long due to the difficulties of feeding them a proper diet of ants.
Diet
Eats mostly ants along with other small invertebrates and some plant material such as berries.
Reproduction
Mates April to May. 1 - 2 clutches of 2 - 16 eggs are laid June - July and buried in sandy soil. Hatchlings appear usually in August to mid September.

Know to hybridize with P. mcallii around Ocotillo and SE of Yuma. (Natureserve)
Range
This subspecies is found in Great Basin Desert habitat at the far northeastern edge of the state. Ranges north into eastern Oregon, southwest Idaho, most of Nevada, western Utah and in an isolated location at the edge of the Utah Colorado border. Intergrades with P. p. calidiarum in the White-Inyo mountains region. (Macey & Papenfuss 1991)

From below sea level to 6,500 ft. (1,980 m). (Stebbins 2003)
Habitat
Inhabits sandy gravelly desert flats, dune systems with low brush, dry washes, and open hillsides with loose soil. Most often seen where desert shrubs are separated by wide sunny clear areas and near desert washes. Patches of sand or loose soil are generally present. Associated plants include sagebrush, big greasewood, saltbush, and other small shrubs.
Taxonomic Notes
Three subspecies of P. platyrhinos have been recognized:

P. p. calidiarum
P. p. platyrhinos
P. p. goodei

Mulcahy et al. (2006, Mol. Ecol. 15:1807-1826) demonstrated that P. p. goodei is a full species, P. goodei, and showed that it occurs in the United States.

Leache and McGuire (2006, Molecular Phylog. Evolution 39:628-644) named four subclades of Phrynosoma - 3 in our area: Anota, Doliosaurus, and Tapaja.
Conservation Issues  (Conservation Status)
None.

Taxonomy
Family Phrynosomatidae Zebra-tailed, Earless, Fringe-toed, Spiny, Tree, Side-blotched, and Horned Lizards
Genus Phrynosoma Horned Lizards
Species platyrhinos Desert Horned Lizard
Subspecies


platyrhinos Northern Desert Horned Lizard
Original Description
Phrynosoma platyrhinos - Girard, 1852 - Proc. Acad. Nat. Sci. Philadelphia, Vol. 6, p. 69

from Original Description Citations for the Reptiles and Amphibians of North America © Ellin Beltz

Meaning of the Scientific Name
Phrynosoma - Greek - phrynos - toad and soma - body - refers to the squat, toad-like appearance
platyrhinos
- Greek -platys - flat and- rhinos - nose - referring to the flat nose

from Scientific and Common Names of the Reptiles and Amphibians of North America - Explained © Ellin Beltz

Alternate Names
Phrynosoma platyrhinos - Desert Horned Lizard
"Horny Toad," "Horned Toad"

Related or Similar California Lizards
Phrynosoma platyrhinos calidiarum - Southern Desert Horned Lizard
Phrynosoma mcallii - Flat-tail Horned Lizard
Phrynosoma coronatum - Coast Horned Lizard
Phrynosoma douglasii - Pygmy Short-horned Lizard

More Information and References
Natureserve Explorer

California Dept. of Fish and Game

Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians. 3rd Edition. Houghton Mifflin Company, 2003.

Behler, John L., & F. Wayne King. The Audubon Society Field Guide to North American Reptiles and Amphibians. Alfred A. Knopf, 1992.

Smith, Hobart M. Handbook of Lizards, Lizards of the United States and of Canada. Cornell University Press, 1946.

Sherbrooke, Wade C. Horned Lizards, Unique Reptiles of Western North America. Southwest Parks and Monuments Association, 1981.

Sherbrooke, Wade C. Introduction to Horned Lizards of North America. University of California Press, 2003.

Brown et. al. Reptiles of Washington and Oregon. Seattle Audubon Society,1995.

St. John, Alan D. Reptiles of the Northwest: Alaska to California; Rockies to the Coast. Lone Pine Publishing, 2002.

Macey, J. Robert and Theodore Papenfuss."Herpetology." The Natural History of the White-Inyo Range Eastern California. Ed. Clarence Hall. University of California Press, 1991.

Conservation Status

The following status listings come from the Special Animals List which is published several times each year by the California Department of Fish and Game.

This animal is not included on the Special Animals List, which indicates that there are no significant conservation concerns for it in California.



Organization
Status Listing
U.S. Endangered Species Act (ESA)
California Endangered Species Act (CESA)
California Department of Fish and Game
Bureau of Land Management
USDA Forest Service
Natureserve Global Conservation Status Ranks
World Conservation Union - IUCN Red List





 

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