Reptiles
Flat-Tailed Horned Lizard
Phrynosoma mcallii · also called flat-tailed horned lizards
A flat-tailed horned lizard shimmies rapidly beneath the surface of a Sonoran Desert sand dune, its unusually flattened, broad body disappearing into the fine, wind-blown sand within seconds. Outside this specific narrow strip of dune habitat, the species exists nowhere else at all.
Overview
The flat-tailed horned lizard, Phrynosoma mcallii, is a flattened, camouflaged lizard native to sand dune habitat within the Sonoran and Colorado Desert regions. Its extreme body flattening and unusually narrow geographic range make it one of the more habitat-restricted horned lizard species in North America.
A body built for one specific kind of sand
Where broader-ranging horned lizard relatives tolerate a variety of desert substrates, the flat-tailed horned lizard has specialised so completely for fine, loose dune sand that its entire survival strategy depends on that one narrow habitat type remaining intact.
Status
Near Threatened — facing ongoing pressure from off-road vehicle activity, development, and habitat fragmentation across its narrow dune range.
Flat-Tailed Horned Lizard: common questions
Why is the flat-tailed horned lizard's body so flat?
A flat-tailed horned lizard has a notably flattened, broad body shape even by horned lizard standards, an extreme camouflage adaptation for blending seamlessly into the fine, wind-blown sand of its narrow dune habitat, making it considerably harder for predators to spot against the shifting sand surface.
How does the flat-tailed horned lizard escape predators?
A flat-tailed horned lizard can rapidly bury itself into loose sand when threatened, using a shimmying motion to disappear beneath the surface quickly enough to escape many potential predators, a technique well suited to the fine, loose sand of its specific dune habitat.
Why is the flat-tailed horned lizard considered at risk?
The flat-tailed horned lizard occupies an unusually narrow natural range restricted to specific sand dune habitat, and because this limited habitat faces ongoing pressure from off-road vehicle activity, urban development, and agricultural conversion, the species is considered a species of significant conservation concern despite still being found across parts of its historical range.
Where does the flat-tailed horned lizard live?
The flat-tailed horned lizard is native to sand dune habitat within the Sonoran and Colorado Desert regions of southeastern California, southwestern Arizona, and northern Mexico, restricted to a considerably narrower range than several other horned lizard species found across the broader American Southwest.