Cophosaurus texanus
Silhouette: SeismicShrimp · PhyloPic
In 3 days ~90% in a week >90%
The greater earless lizard (Cophosaurus texanus) is the only species in the monotypic genus Cophosaurus. It is closely related to the smaller, lesser earless lizards and other species in the genus Holbrookia, and in fact was placed in that genus and referred to Holbrookia texana from 1852 into the 1970s. Earless lizards lack external ear openings, an adaptation to burrowing in the sand, as are the recessed lower jaw and flared upper labial scales. Greater earless lizards are sexually dimorphic, males grow larger and are more colorful than females, exhibiting pink and green colors that are particularly bright in the breeding season. Two bold black bars mark the lateral region of males but are greatly reduced and vague, or occasionally entirely absent in females.
The greater earless lizard is native to the Chihuahua Desert and other arid and semi-arid regions of Southwestern United States and northern Mexico, where they most often occupy moderately open areas of sparse vegetation with rocks, gravel, and sand. The overall color of individual lizards frequently match the colors of the rocks and soils of the local area they inhabit. They will often rely on camouflage and their speed to elude threats and predators before retreating into rock crevices. They are primarily insectivores, preying on wide variety of crickets, grasshoppers, caterpillars, ants, flies, beetles, and bugs. Spiders and small lizards are occasionally eaten as well. Cophosaurus are oviparous. Females lay 1 to 4 clutches of 2 – 9 eggs a year, with hatchlings emerging from June to October, and reaching adult size and sexual maturity in one year. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Guadalupe Mountains National Park | 🇺🇸 United States | |
| 2 | Big Bend National Park | 🇺🇸 United States | |
| 3 | Saguaro National Park | 🇺🇸 United States | |
| 4 | Cumbres de Monterrey National Park | 🇲🇽 Mexico |
Likely
About 60% of wildlife watchers report a Greater Earless Lizard sighting in Big Bend National Park on a given day, based on 514 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the most-seen of the 48 reptiles we can rate there. Over three days the chance rises to about 90%, and over a week to over 90%, if each day is a fresh chance.
April–May and October
In those months about 70% of wildlife watchers report a Greater Earless Lizard in Big Bend National Park on a given day, against about 20% in December and January, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Greater Earless Lizard sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 4
Of the 4 parks where we can rate Greater Earless Lizard sightings, Big Bend National Park ranks 2nd at about 60%. The best odds are in Guadalupe Mountains National Park (United States, about 80%).
Same family: Phrynosomatidae
The closest relatives of the Greater Earless Lizard that you can see in Big Bend National Park (family Phrynosomatidae, Phrynosomatid Lizards) are Canyon Lizard (about 30%), Common Side-blotched Lizard (about 30%) and Crevice Spiny Lizard (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Greater Earless Lizard is recorded against all the reptiles logged in Big Bend National Park (514 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
