Overview
The Greater Earless Lizard (Cophosaurus texanus) is a swift, charismatic desert lizard common to the rugged canyonlands and rocky washes of the American Southwest and northern Mexico. Entirely lacking external ear openings to prevent sand and gravel from entering its skull while diving into loose soil, it is famous for raising and curling its bold, zebra-striped tail like a scorpion over its back when running.
Biology and Physical Characteristics
The Greater Earless Lizard has a streamlined, agile body with smooth granular scales and an earless head (the tympanic membrane is covered by scaly skin). Adult males in breeding condition exhibit breathtaking coloration: their pale grey-tan dorsal ground color gives way to brilliant pastel turquoise, sky-blue, and peach on the flanks and belly, punctuated just in front of the hind legs by two bold, jet-black crescent bars. The underside of the tail features sharp, contrasting black-and-white zebra bars.
Behavior and Ecology
A thermophilic diurnal sprinter, this lizard basks on blazing white limestone boulders until its body temperature reaches roughly 38 degrees Celsius. When walking or fleeing, it curls its tail tightly over its back, displaying the bold black-and-white banded underside in a behavior known as ‘tail flagging.’ This display acts both as a pursuit deterrent signaling health to predators and as an optical distraction that directs attacks safely away from its vulnerable head toward its tail tip.
Conservation and Human Impact
Assessed as Least Concern by the IUCN, the Greater Earless Lizard is widely distributed and abundant across vast expanses of protected desert canyons and state parks throughout Texas and New Mexico. It thrives in rocky terrain that is generally unsuitable for human agriculture or urban development.
Interesting Factoid
The Greater Earless Lizard has no ear holes at all; its eardrum is completely covered by thick scaly skin so it can dive headfirst into coarse gravel without getting dirt in its ears.