Phrynosoma modestum
The roundtail horned lizard (Phrynosoma modestum) is a small, flat-bodied lizard native to the arid regions of the southwestern United States and northcentral Mexico. Its coloration typically matches its soil environment, providing camouflage. A distinctive feature is its crest of short, equal-length horns and its unique defense mechanism of hunching its body to resemble a rock.
Key Facts
- ›Native to arid regions of the southwestern us and northcentral Mexico.
- ›Possesses a distinctive crest of short, equal-length horns.
- ›Coloration usually matches the soil of its habitat, ranging from gray to brown or yellow.
- ›Relies on hunching its body into a rock-like shape for camouflage.
- ›Primarily feeds on ants, especially honeypot ants.
- ›Lays eggs in early summer.
Roundtail Horned Lizard
United States, Mexico
Semi-Arid Rocky and Sandy Habitats, Sparse Vegetation
- Short, Flat, Round Body
- Short Limbs
- Small Head
- Distinctive Crest of Nearly Equal-Length Horns
- Lacks A Fringe of Lateral Scales
- Coloration Typically Matches Soil, Ranging From Gray, Light Brown, To Pale Yellow
- May Have Darker Regions Around the Neck and Groin
- Sometimes Exhibits Striping On the Tail
Harvester Ants, Honeypot Ants
- Hunches Body Into the Shape of A Rock For Camouflage
- Boldly Casts A Shadow For Concealment
About Phrynosoma modestum
Phrynosoma modestum: The Roundtail Horned Lizard
The roundtail horned lizard, scientifically known as Phrynosoma modestum, is a distinctive member of the horned lizard genus, recognized for its relatively small size and unique adaptations to its arid environment. This species is native to the semiarid regions of the southwestern United States, including western Texas, New Mexico, eastern Arizona, and southeastern Colorado, as well as extending into eight states in northcentral Mexico, where it is known locally as tapayaxtin.
Habitat and Diet
The preferred habitat of Phrynosoma modestum consists of rocky and sandy terrain characterized by sparse vegetation. Crucially, these lizards are often found in proximity to ant colonies, particularly those of harvester ants and honeypot ants, as these insects form the cornerstone of their diet. Their survival is closely tied to the availability of these ant species.
Physical Characteristics and Defense
Phrynosoma modestum is characterized by its short, flat, and round body, complemented by short limbs and a small head. A defining feature is the crest of horns on its head, which are of nearly equal length. Unlike some of its relatives, it lacks a fringe of lateral scales. Its coloration typically mirrors the soil of its surroundings, appearing in shades of gray, light brown, or pale yellow, sometimes with darker markings on the neck and groin, or striping on the tail. When threatened, the roundtail horned lizard employs a unique defense strategy: instead of flattening itself to reduce its shadow, it hunches its body into a shape resembling a rock, effectively blending with the landscape and casting a shadow that further aids in concealment.
Reproduction and Size
This species is oviparous, reproducing and laying its eggs during the early summer months. In terms of size, Phrynosoma modestum is quite small. The maximum recorded snout-to-vent length (SVL) is approximately 7 cm (2.7 inches), with a total length, including the tail, not exceeding 10.5 cm (4.3 inches).
Source: Wikipedia ↗
Frequently Asked Questions
What is the scientific name for the roundtail horned lizard?
The scientific name for the roundtail horned lizard is Phrynosoma modestum. The specific epithet 'modestum' is Latin and translates to 'modest' or 'calm'.
Where does the roundtail horned lizard live?
This species is native to the United States, found in western Texas, New Mexico, eastern Arizona, and southeastern Colorado. It also inhabits eight states in northcentral Mexico.
What kind of habitat does the roundtail horned lizard prefer?
The roundtail horned lizard prefers rocky and sandy, semiarid environments with sparse vegetation. It is often found near colonies of harvester ants or honeypot ants, which are its main food source.
How does the roundtail horned lizard protect itself?
Unlike some other horned lizards, the roundtail horned lizard lacks a fringe of lateral scales. Instead, it hunches its body into the shape of a rock, which serves as camouflage and casts a shadow that aids in concealment.
What is the typical size of a roundtail horned lizard?
The roundtail horned lizard is a small species. The maximum recorded size is 7 cm (2.7 inches) for snout-to-vent length and 10.5 cm (4.3 inches) for total length, including the tail.
What does the roundtail horned lizard eat?
The primary diet of the roundtail horned lizard consists of ants, with a particular preference for honeypot ants. It is often found near ant colonies to facilitate its feeding.
When do roundtail horned lizards reproduce?
The roundtail horned lizard is oviparous, meaning it lays eggs. Breeding and egg-laying typically occur in early summer.
Related Lizards
Aspidoscelis laredoensis
The Laredo striped whiptail (Aspidoscelis laredoensis) is a lizard species native to southern Texas and northern Mexico. It is known for its dark green or brown coloration, distinguished by seven yellow or white stripes extending from head to tail, and a white underside. This species is parthenogenic, meaning females reproduce without fertilization, and it is a fast-moving, diurnal insectivore.
Aspidoscelis marmorata marmorata
The marbled whiptail (Aspidoscelis marmoratus) is a slender, diurnal lizard found in the arid and semi-arid regions of the southwestern United States and northern Mexico. It is characterized by its grey or black coloration adorned with 4 to 8 yellow or white stripes, often with dark mottling, creating a marbled effect. This energetic species is known for its speed and wariness, darting into cover when approached.
Laredo striped whiptail
The Laredo striped whiptail is a slender lizard native to southern Texas and northern Mexico, characterized by its dark green or brown coloration and seven distinctive yellow or white stripes running from head to tail. This species is known for its energetic and fast-moving nature, preferring habitats with sandy soils and sparse vegetation. A notable reproductive feature is parthenogenesis, where females lay unfertilized eggs.