Round-tailed Horned Lizard
A pancake-shaped lizard with horns along the rear crest of its head.
About This Species
Southeastern Colorado represents the farthest northern part of the round-tailed horned lizard's range. In some cases, when the lizard is threatened, it will squirt blood out of its eyes.
More Information:
Physical Characteristics
Back of head with four enlarged spines of about equal length; tail cylindrical and banded; sides of body between front legs and hind legs lack a fringe of enlarged scales; upper side grayish, brownish, yellowish, reddish, or bluish (hue often matches soil color), with dark blotch on each side of neck and on body just in front of each hind leg (patterning may change with temperature); maximum snout-vent length about 6.6 cm (2.6 inches) in males, 7.1 cm (2.8 inches) in females. This lizard’s unusual color pattern and behavior, including a humpbacked posture when immobile, cause it to strongly resemble a small stone.
Mature Male
Underside of base of tail with two bulges (from hemipenes).
Range
Known to be in only a few locations in southeastern Colorado.
Habitat
Dry grassland and shrubland, including lowland slopes and arroyo margins and gravelly to rocky soils.
Diet
Ants generally dominate the diet.
Reproduction
Females produce a clutch of eggs in June-July, perhaps as early as late May. Hatchlings probably emerge in late July or August.
Threats to Species
- Development
- Habitat loss
- Off-road vehicles
- Illegal collection