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Southern Desert Horned Lizard
(Phrynosoma platyrhinos calidiarum)

aka Desert Horned Lizard (Phrynosoma platyrhinos)
Lizards Around Las Vegas, Wildlife Around Las Vegas
Horned Lizard
Adult (Desert NWR)

General Description: These are small to medium-sized (3 to 5 in.) lizards with broad, flattened bodies and a row of horns on the back of the head. With a toad-like body form, these lizards are often called “horny toads.”

This is the only species of Horned Lizard in southern Nevada.

Taxonomy: Phrynosomatid Lizard Family (Phrynosomatidae).

Horned Lizard
Long head spines

Technical Description: Body length to almost 4 in.; tail about 1 in. Body flat; edge of sides with one row of small, fringed scales. Head fringed with row of horns. Some dorsal scales sharp-pointed. Throat with one row of slightly enlarged scales on each side. Dorsum blotched with a pattern and color resembling the background; base color beige, tan, or reddish; darker blotches form crescents. Ventral color cream. Snout blunt.

The southern and northern subspecies are separated by geography, horn size, and tail shape:

Horned Lizard
Normal, slender appearance
  • In the northern subspecies (Great Basin Desert), the two longest horns are short and set far apart (length usually less than 45% of head length; space between horn bases roughly equal to the width of the horn at the base) and the tip of the tail is more round.

  • In the southern subspecies (Mojave Desert), the two longest horns are long and set close together (horn length usually more than 45% of the head length; space between the bases about half of the width of the horn at the base) and the tip of the tail is more flat.

Horned Lizard
Puffed up trying to look too big to eat

Diet: These lizards eat ants; occasionally eating other slow-moving insects, beetles, spiders, and some plant material. Often found near anthills where they sit and wait for passing ants.

Habitat: These lizards occur in most low-desert habitats, especially Creosote-Bursage Flats and Mojave Desert Scrub habitat types with sandy areas in the south, and in Sagebrush and greasewood flats in the north (Great Basin). Typically found among woody shrubs, cacti, and yucca on sandy flats, alluvial fans, washes, and dunes below about 6,500 ft. Also found in Mesquite-Catclaw areas, salt desert scrub, and Pinyon-Juniper Woodland habitats.

Horned Lizard
Unmarked, white belly

Range: The species occurs from southeastern Oregon and southwestern Idaho south to northwestern Mexico. The southern subspecies occurs in the southern part of the range in the Mojave and other southern deserts Nevada (south edge of the Nevada Test Site) southward. The northern subspecies occurs in the northern part of the range in the Great Basin Desert (south edge of the Nevada Test Site northward).

Breeding: Mate during spring; lay 1 or 2 clutches of 2 to 16 eggs in early summer; hatch in late summer.

Similar Species: There are no other species of horned lizards in central and southern Nevada. The Short-horned Lizard (Phrynosoma douglassii) occurs in northern-most Nevada, and it can be identified by very short horns on the head.

Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum)
Notice the broad tail base and spikes

Comments: Although Horned Lizards are gentle, they can hiss, threaten to bite, and puff up with air to look bigger and fiercer. In areas with soft sand, they will shake themselves vigorously, throwing sand over their backs and leaving only their head exposed so they can hide from predators while waiting for passing ants.

Often called “horny toads,” these lizards are favored as pets. However, they often do not survive in captivity because of difficulties in adequately providing their specialized diet of ants.

Desert Horned Lizard (Phrynosoma platyrhinos) Scale pattern on throat; note that the row of enlarged throat scales are only slightly larger than adjacent throat scales.
lizard throat
Compare the slightly enlarged throat scales of the Desert Horned Lizard (Phrynosoma platyrhinos), above, with the much enlarged throat scales of a Flat-tailed Horned Lizard (Phrynosoma mcallii). Flat-tailed photo © 2006 S. Ferrand
Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum) Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum)
Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum) Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum)
Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum) Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum)
Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum)
Hatchling horned lizard
Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum)
Hatchling horned lizard blending in with the desert
Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum) Southern Desert Horned Lizard (Phrynosoma platyrhinos calidiarum)
Horned Lizard more to come ...

Note: All distances, elevations, and other facts are approximate.
© 2014 Jim Boone; Last updated 120907

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