The roundtail horned lizard (''Phrynosoma modestum'') is one of the smaller

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

horned lizard ''Phrynosoma'', whose members are known as the horned lizards, horny toads, or horntoads, is a genus of North American lizards and the type genus of the Family (biology), family Phrynosomatidae. Their common names refer directly to their horns or ...

. Their specific epithet is from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

word ''modestum'', meaning modest or calm. They are found in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, in western

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

eastern

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

, southeastern

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

and eight states in northcentral

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

where they are referred to as "''tapayaxtin''".

Habitat

Roundtail horned lizards prefer rocky and sandy, semiarid habitat with sparse vegetation, near

harvester ant Harvester ant is a common name for any of the species or genera of ants that collect seeds (called seed predation), or mushrooms as in the case of '' Euprenolepis procera'', which are stored in the nest in communal chambers called granaries. T ...

or especially honeypot ant colonies, which is their primary

diet Diet may refer to: Food * Diet (nutrition), the sum of the food consumed by an organism or group * Dieting, the deliberate selection of food to control body weight or nutrient intake ** Diet food, foods that aid in creating a diet for weight loss ...

Description

The color of roundtail horned lizards usually reflects the color of the soil in their native habitat. Most are uniformly

grey Grey (more frequent in British English) or gray (more frequent in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning that it has no chroma. It is the color of a cloud-covered s ...

in color, but they can also be light

brown Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing and painting, brown is usually made by combining the colors Orange (colour), orange and black. In the ...

, or even a pale

yellow Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In t ...

. Often, darker-colored regions occur around the neck and groin, and sometimes striping on the tail. They are short, flat, round-bodied lizards with short limbs, and small heads, which have a distinctive crest of nearly equal-length horns. Unlike other horned lizards, they lack a fringe of lateral scales and do not seek to flatten themselves to the ground to eliminate shadow; instead, they hunch their bodies into the shape of a rock for

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

, boldly casting a shadow. Their maximum size is 7 cm (2.7 in) snout-to-vent length, and 10.5 cm (4.3 in) total length. Smith, H.M. and E.D. Brodie, Jr. (1982). ''Reptiles of North America, A Guide to Field Identification''. Golden Press. New York. pp. 126–127. Phrynosoma_modestum2

Reproduction

Roundtail horned lizards are

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

, breeding and laying

eggs An egg is an organic vessel in which an embryo begins to develop. Egg, EGG or eggs may also refer to: Biology * Egg cell, the female reproductive cell (gamete) in oogamous organisms Food * Eggs as food Places * Egg, Austria * Egg, Switzerland ...

in early summer.

References

Bibliography

*Hammerson, Geoffrey A. ''Amphibians and Reptiles in Colorado''. 2nd edition.

External links

Herps of Texas: ''Phrynosoma modestum''Horned Lizard Conservation Society
{{Authority control Phrynosoma Reptiles of Mexico Reptiles of the United States Fauna of the Southwestern United States Reptiles described in 1852