CaliforniaHerps.com

A Guide to the Amphibians
and Reptiles of California


Southern Desert Horned Lizard -
Phrynosoma platyrhinos calidiarum

Cope, 1896

(=Doliosaurus platyrhinos calidiarum)
Click on a picture for a larger view



Desert Horned Lizards Range Map
Range in California: Red

Green: Northern Desert Horned Lizard




observation link



SoCalHerpsCover
iPhone App
Electronic Field Guide to the
Reptiles and Amphibians of
Southern California
Available Now at the
iTunes App Store.




Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard
Adult, Inyo County Adult, Inyo County Adult, Inyo County Adult, Inyo County
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard
Adult, Kern County Adult, Kern County Adult, Kern County
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard
Adult, Kern County Adult, San Diego County Adult, Kern County
© Todd Battey
Striped adult, Kern County
© Todd Battey
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard  
Horned Lizards in lava rock habitat tend to have dark coloring to match the dark soil, as you can see on this adult from San Bernardino County. (Both are the same lizard; the picture on the right was taken with flash.)   © Filip Tkaczyk Adult, San Bernardino County  
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard  
Adult, San Bernardino County  © Jeff Ahrens  
Southern Desert Horned Lizard Great Basin Collared Lizard Southern Desert Horned Lizard  
Adult, San Bernardino County, with closed nasal valves.
Horned lizards can close their nasal valves to keep soil from entering their nostrils and lungs when they bury themselves. The closed valves leave a small crescent-shaped opening through which the lizard can still breathe when it is buried.  © Filip Tkaczyk

Desert Horned lizards are covered with small granular scales interspersed with larger pointed scales on the dorsal surfaces. Desert Horned Lizards have one row of fringe scales on each side. Compare with the Coast Horned Lizard which has two rows of fringe scales on each side.

 
Juveniles
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard
Juvenile, basking on a low rock in the early morning, Kern County Juvenile, Kern County Juvenile, Kern County Juvenile, Kern County
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard  
Juvenile, eastern Riverside County
© Geoff Fangerow
When threatened, horned lizards will sometimes squirt blood from the eyes to deter predators, as this one did.

Neonate, Kern County. © Todd Battey Juvenile, San Bernardino County
© Jeff Ahrens
 
Breeding Behavior
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard
Jay Snow shot this series (left to right, top to bottom) of a mating pair of Desert Horned Lizards one day in late May in Death Valley National Park. © Jay Snow

Predators
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard
Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard Southern Desert Horned Lizard
Jay Snow took this series (left to right, top to bottom) of a Red Racer trying to eat a live Southern Desert Horned Lizard over a period of 44 minutes. The snake failed to swallow the lizard and crawled away. In the last picture you can see that the lizard lay prone for several minutes after the coachwhip left then took up to 15 minutes to clean the saliva off its face before slowly walking away, no doubt thankful for the row of horns behind its head.
© Jay Snow

Habitat
Southern Desert Horned Lizard Habitat Southern Desert Horned Lizard Habitat Southern Desert Horned Lizard Habitat  
Adult in situ basking on a rock,
San Diego County
Habitat, Kern County Habitat, Inyo County  
Southern Desert Horned Lizard Habitat Southern Desert Horned Lizard Habitat Southern Desert Horned Lizard Habitat Southern Desert Horned Lizard Habitat
Habitat, San Bernardino County

Habitat, San Bernardino County Habitat, Riverside County Habitat, Inyo County
Short Video
Southern Desert Horned Lizard      
I found this horned lizard basking on a rock on a cool morning in the Mohave Desert. It only had two speeds - sit still and hide, and run away as fast as you can.      
Description

Size
2.5 - 3.75 inches long from snout to vent (6.4 - 9.5 cm). (Stebbins 2003)
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 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, but can be active on the surface at any time of the year. Most active from April to July. Can be seen basking on rocks and road berms in the morning.

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 nearly 90 percent ants, along with other small invertebrates including flies, and some plant material such as berries.
Reproduction
Mates April to May. 1 - 2 clutches of 2 - 16 eggs are laid June - July. Hatchlings appear usually in August to mid September.

Know to hybridize with P. mcallii around Ocotillo and SE of Yuma. (Natureserve)
Range
In California, this subspecies is found throughout the Colorado and Mojave deserts, east and north of the southern mountain ranges to the Colorado River and Baja California border, and north through the Owens Valley to near the Nevada border where it intergrades with P. p. platyrhinos in the White-Inyo mountains region. (Macey & Papenfuss 1991) Ranges out of California south along the eastern side of Baja California, through the eastern part of Arizona, the southern tip of Nevada, and extreme southeast Utah, and along the northern coast of Sonora, Mexico.
The species Phrynosoma platyrhinos occurs in southern California and northeastern Baja California, throughout most of Nevada, along the extreme northeastern edge of California, in southeast Oregon and southern Idaho, in western Utah and a couple of isolated spots in northeastern Utah, and western Arizona.
From below sea level to 6,500 ft. (1,980 m). (Stebbins 2003)
Habitat
Found in arid lands including sandy flats, at the edges of sand dunes, alluvial fans, and dry washes. Patches of sand are generally present. Associated plants include creosote, salt bush, cacti, 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 Fitzinger, 1843
Genus Phrynosoma Horned Lizards Wiegmann, 1828
Species platyrhinos Desert Horned Lizard Girard, 1852
Subspecies

calidiarum Southern Desert Horned Lizard Cope, 1896
Original Description
Phrynosoma platyrhinos - Girard, 1852 - Proc. Acad. Nat. Sci. Philadelphia, Vol. 6, p. 69
Phrynosoma platyrhinos calidiarum - (Cope, 1896) - Amer. Nat., Vol. 30, p. 833

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
calidiarum - Latin - calidus - hot, warm and -arum - pertaining to, of the nature of - refereing to this lizard's habitat in hot areas

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 platyrhinos - Northern 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

Horned Lizard Conservation Society

Stebbins, Robert C., and McGinnis, Samuel M.  Field Guide to Amphibians and Reptiles of California: Revised Edition (California Natural History Guides) University of California Press, 2012.

Stebbins, Robert C. California Amphibians and Reptiles. The University of California Press, 1972.

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

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

Powell, Robert., Joseph T. Collins, and Errol D. Hooper Jr. A Key to Amphibians and Reptiles of the Continental United States and Canada. The University Press of Kansas, 1998.

Bartlett, R. D. & Patricia P. Bartlett. Guide and Reference to the Turtles and Lizards of Western North America (North of Mexico) and Hawaii. University Press of Florida, 2009.

Jones, Lawrence, Rob Lovich, editors. Lizards of the American Southwest: A Photographic Field Guide. Rio Nuevo Publishers, 2009.

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.

Lemm, Jeffrey. Field Guide to Amphibians and Reptiles of the San Diego Region (California Natural History Guides). University of California Press, 2006.

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 and the Endangered and Threatened Animals List which are published by the California Department of Fish and Wildlife.


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) None
California Endangered Species Act (CESA) None
California Department of Fish and Wildlife None
Bureau of Land Management None
USDA Forest Service None

 

Home Site Map About Us Identification Lists Maps Photos More Lists CA Snakes CA Lizards CA Turtles CA Salamanders CA Frogs
Contact Us Usage Resources Rattlesnakes Sounds Videos FieldHerping Yard Herps Behavior Herp Fun CA Regulations
Beyond CA All Herps


Return to the Top

 © 2000 -