Overview
The Chihuahua Fringe-toed Lizard (Uma paraphygas) is an ultra-specialized sand-swimming reptile endemic to the isolated, sun-baked sand dune fields of the Mapimí Biosphere Reserve in the Chihuahuan Desert of Mexico. Exquisitely adapted to a life on shifting sand, it possesses comb-like scales along its toes that act like biological snowshoes, allowing it to sprint across loose powder sand and dive headfirst beneath the dunes to ‘swim’ invisible through the sand.
Biology and Physical Characteristics
Uma paraphygas features a flattened, aerodynamic body with a pale greyish-tan ground color adorned with an intricate, lace-like network of dark brown rings and spots that perfectly mimics the texture of sun-bleached desert sand. Its underside is creamy-white with distinctive black lateral spots on the belly. Its toes are lined with long, pointed, projecting fringe scales, and its eyelids have interlocking scales that seal out fine dust particles.
Behavior and Ecology
When threatened by a coachwhip snake or roadrunner, the lizard sprints across loose dune faces at blinding speeds before executing an astonishing maneuver: it drives its wedge-shaped snout straight into the loose sand and shuffles its body rapidly sideways, disappearing beneath the dune surface in a fraction of a second, breathing air trapped between sand grains through modified nasal valves.
Conservation and Human Impact
Classified as Vulnerable by the IUCN, the Chihuahua Fringe-toed Lizard occupies an extremely restricted geographic range of isolated dune patches. Extensive conversion of desert dune buffers for irrigated agriculture, cattle overgrazing of dune-stabilizing vegetation, and off-road vehicle disturbance represent major ongoing threats.
Interesting Factoid
To escape predators, the Chihuahua Fringe-toed Lizard dives headfirst into loose sand dunes and literally ‘swims’ underwater through the sand, using specialized valves in its nose and ears to keep sand out while it breathes.