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Texas Horned Lizard

Phrynosoma cornutum (aka Texas Horned Toad)

Description

This lizard gets its "horned" designation from the two very prominent spines on the top of the head. It also has spines on the back of the head, above each eye, along its lower jaw, and along both sides of its flattened body.

Texas Horned Lizard

The ventral surface of the lizard is either gray or tan, while the dorsal surface is tan or gray with white and red or yellow highlights. On most individuals, a light line can be seen extending from its head down the middle of its back. It is the only species of horned lizard to have dark brown stripes that radiate downward from the eyes and across the top of the head.

The average length of the Texas horned lizard is 2-1/2 inches from nose to vent, with an overall length of about 7-1/2 inches.

Distribution and Habitat

The Texas horned lizard is found from Kansas to Northern Mexico and from Arizona to Louisiana. It lives mainly in sandy areas where it often inhabits abandoned animal burrows, usually in close proximity to the nests of harvester ants, and at altitudes of up to 6,000 feet.

Diet

Texas horned lizards feed mainly on harvester ants, but will also eat grasshoppers, isopods, beetles, and beetle larvae. In order to obtain enough energy, adult Texas Horned Lizards must forage from several colonies of harvester ants, and their daily activities are planned around the times of highest ant activity

Reproduction

Breeding season begins in late April and continues into July. After mating, the female lays 40 or more eggs (each about 1-1/2 inches in diamater) in a burrow. She will incubate them for about a week before leaving the burrow, never to return. The eggs will hatch after another 4-6 weeks. Hatchlings are approximately 1-1/4 inches long and are relatively smooth, but they do have the spines around their heads. The age of reproductive maturity is not known, however they are full-grown adults at 3 years of age.

Other Behaviors and Habits

Texas horned lizards are most active during the cooler parts of the day.

Hibernation season lasts from late summer to late spring. During hibernation the animal will slow down its metabolism and can persist for long periods of time without food or water. Mating season begins soon after hibernation ends.

During heavy rains the lizard will stand high on its feet, spread its body out flat, and lower its head so that falling rain will be funneled to the mouth through interscalar channels.

The Texas horned lizard's first response to a threat is to "freeze" and allow itself to "blend" into the background. If that doesn't work, it will inflate itself, making it virtually impossible for a predator to swallow it (due to the spines). If the predator persists, the lizard can squirt up 1/3 of its volume of blood out of a pore near the eye. The blood apparently has a very foul taste, as virtually every predator that gets hit with it (especially in the mouth) backs off almost immediately.

Conservation Status

The Texas horned lizard is listed as a threatened species in Texas (where it is the official state reptile) and Okalahoma.

Scientific Classification

phylum Chordata
subphylum Vertebrata
class Reptilia
order Squamata
suborder Sauria
family Iguanidae
genus & species Phrynosoma cornutum

SOURCE
Animal Diversity Web animaldiversity.org/accounts/Phrynosoma_cornutum/

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This page was last updated on July 07, 2017.