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.
Etymology The generic name Cophosaurus is derived from the Greek words copho (κουφός), meaning "deaf", and saurus, meaning "lizard", in reference to the animal's absent external ear openings. The trivial name, or specific epithet texanus, is a toponym in reference to the state of Texas, the original location where the specimens used in the lizard's description were collected.Lemos Espinal, Julio A., Hobart M. Smith, James R. Dixon, and Alexander Cruz. 2015. Amphibians and Reptiles of Sonora, Chihuahua, and Coahuila, Mexico, Vol. I & II. CONABIO, Mexico D. F. 668 pp. (Vol. II pages 202-203 & 595) The subspecific names are both Latin, reticulatus, meaning "reticulated" or a "net-like" pattern,Lewis, Charlton Thomas 1879. A Latin Dictionary: Founded on Andrew's Edition of Freund's Latin Dictionary, revised, enlarged, and in great part rewritten by Charlton Thomas Lewis, Ph. D. Oxford University Press. Oxford. xiv, 2019 pp. 1993 edition and scitulus, meaning "handsome" or "pretty".
Taxonomy
Within the family Phrynosomatidae, Cophosaurus is most closely related to the zebra-tailed (Callisaurus), lesser earless (Holbrookia) and fringe-toed lizards (Uma), collectively forming the tribe Callisaurini, commonly referred to as the sand lizards.de Queiroz, Kevin. 1992. Phylogenetic relationships and rates of allozyme evolution among the lineages of sceloporine sand lizards. Biological Journal of the Linnean Society. 45: 333-362.Uetz, Peter, Paul Freed, R. Aguilar, and J. Hošek (editors). 2022. The Reptile Database, http://www.reptile-database.org. Cophosaurus texanus TROSCHEL, 1852 (accessed June 5, 2022) The genus Cophosaurus is monotypic, as Cophosaurus texanus is the only species within the genus. Franz Hermann Troschel described Cophosaurus (as well as the species C. texanus) in a paper dated to 1850 (but not published until 1852). Later, that same year, the species was transferred to the genus Holbrookia in a review by Spencer Fullerton Baird and Charles Frédéric Girard, and subsequent literature used the name H. texana for well-over a century.Baird, Spencer F. and Charles F. Girard. 1852. Characteristics of some new reptiles in the Museum of the Smithsonian Institution, part 2. Proc. Acad. Nat. Sci. Philadelphia 6: 125-129. (page 125) Troschel's description was based on two specimens, cotypes or syntypes, both lost in the Second World War. In 1951, James A. Peters published a review of the species, recognizing three subspecies and designating a neotype for C. t. texanus, although still placing them in the genus Holbrookia.Peters, James A. 1951. Studies on the lizard Holbrookia texana (Troschel) with descriptions of two new subspecies. Occasional Papers of the Museum of Zoology University of Michigan, (537): 1-20. In a 1958 Ph.D. dissertation reviewing the genus Holbrookia, herpetologist Ralph W. Axtell omitted H. texana with little comment,Axtell, Ralph W.1958. A monographic revision of the iguanid genus Holbrookia. Ph. D. dissertation. Univ. Texas, viii + 222 pp. something which was noted by Robert F. Clarke in his 1965 Ph.D. dissertation (subsequently placing the species back in the original genus, Cophosaurus).Clarke, Robert F. 1965. An ethological study of the iguanid lizard genera Callisaurus, Cophosaurus, and Holbrookia. The University of Oklahoma, Ph.D. Dissertation,. Emporia Slate Research Studies, 13: 1-66. (page 5) Both combinations, C. texanus and H. texana, were used by various authors during the 1970s, although, despite arguments for the placement of the species in Holbrookia,Guttman, Sheldon. I. 1970. An electrophoretic study of the hemoglobins of the sand lizards, Callisaurus, Cophosaurus, Holbrookia, and Uma. Comparative Biochemistry and Physiology 34(3): 569-574.Cox, Douglas C. & Wilmer W. Tanner. 1977. Osteology and Myology of the Head and Neck Regions of Callisaurus, Cophosaurus, Holbrookia, and Uma (Reptilia: Iguanidae). Great Basin Naturalist 37(1): 35-56. Cophosaurus was in predominant use by the 1980s; later allozymes analyses supported the recognition of the genus.
Three subspecies are currently recognized (2022), with standardized English names.Society for the Study of Amphibians and Reptiles: Checklist of the Standard English Names of Amphibians & Reptiles. (accessed June 3, 2022) Texas greater earless lizard,Liner, Ernest A. and Gustavo Casas-Andreu. 2008. Standard Spanish, English and scientific names of the amphibians and reptiles of Mexico. Society for the Study Amphibians and Reptiles. Herpetological Circular 38: i-iv, 1-162. (page 57) Crother, Brian I. (ed.). 2017. 'Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding. SSAR Herpetological Circular 43, 1–102 pp. [see page 43-44] Cophosaurus texanus texanus, Troschel 1852 Troschel, Franz H. 1852. Cophosaurus texanus, neue Eidechsengattung aus Texas. Archiv für Naturgeschichte 16 (1): 388-394 . Sonoran greater earless lizard, Cophosaurus texanus reticulatus, (Peters 1951) Chihuahuan greater earless lizard, Cophosaurus texanus scitulus, (Peters 1951)
Description The greater earless lizard is a medium-sized lizard (relative to other species in its range) and the largest of the earless lizards. A range of sizes have been reported by various authors: Texas greater earless lizard (C. t. texanus), males , females ; Chihuahuan greater earless lizard (C. t. scitulus), males , females in total lengths are representative of the species.Conant, Roger and Joseph T. Collins. 1998. A Field Guide to Reptiles and Amphibians: Eastern and Central North America. Houghton Mifflin Company. New York, N. Y. xviii, 616 pp. (pages 222–223)
Greater earless lizards do not have external ear openings. The scales on the body are small and granular, with the dorsal scales slightly smaller than the ventral scales. Their legs, particularly the hind legs, are relatively long. The tail is slightly flattened and longer than head and body combined. The underside of the tail is white with 5 to 9 (usually 6 or 7) bold, contrasting black bands (excluding individuals with regenerated tails). The base color can be various shades of grays, browns, tans, or reddish brown and generally close to the prevailing colors of the local substrate. Cophosaurus texanus is a sexually dimorphic species, in addition to size differences, males and females differ in some aspects of colors and markings. Most noticeable in males are a pair of black bands located on the posterior third on the sides of the body, rising from two blue patches on the margins of the belly up sides and arching forward and ending before meeting on the back. The body anterior to the black bands is suffused with some shade of pink, orange, or red, and the body posterior to the black bands tented green, aqua-green, or lime-green. The colors are most prominent in the Chihuahuan greater earless lizard (C. t. scitulus) and are greatly enhanced and most noticeable in the breeding season in all subspecies. In parts of their range they are colloquially referred to as "the lizard with the pink shirt and green pants." In contrast, females either lack the black lateral bands entirely or they are very faint and indistinct. Females and young often exhibit a lateral white or near white stripe running between the forelimbs and hind limbs and on the back of the legs.Howland, Jeffrey M. 2009. Greater Earless Lizard Cophosaurus texanus, Troschel, 1852. pages 146-149 IN Lawrence L. C. Jones and Robert E. Lovich (editors). Lizards of the American Southwest, A Photographic Field Guide. Rio Nuevo Publishers. Tucson, Arizona. 567 pp. Stebbins, Robert C. and Samuel M. McGinnis. 2018. Peterson Field Guide to Western Reptiles and Amphibians, 4th ed. Houghton Mifflin Harcourt Publidhing Co. New York, N.Y. xi, 560 pp. (pages 276-277)
The subspecies were diagnosed in the original description with the following characters. Cophosaurus t. texana: typically, 80–86%, have 79 ventral scales or less from collar (last gular fold) to anus, 40 or more scales in head length, and 27 or less total femoral pores. Cophosaurus t. scitula: 80–84% have 80 or more ventral scales, 39 or less head scales, 28 or more femoral pores. Cophosaurus t. reticulata: 85–100% have 82 ventral scales, 36 or less head scales, less than 31 femoral pores, and the black lateral bars are faint and do not extend above the lateral fold in males.
Distribution
The greater earless lizard occurs in the southwestern United States (Arizona, New Mexico, and Texas) and northern Mexico (Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Sonora, Tamaulipas, and Zacatecas). Elevations ranging from 127 to 2100 meters have been reported.Farr, William L., David Lazcano, and Paablo A. Lavin-Murcio. 2013. New Distributional Records for Amphibians and Reptiles from the State of Tamaulipas, Mexico III. Herpetological Review 44(4): 631-645. (pages 634-635) Thomason, Libby. 2018. Cophosaurus texanus, Greater Earless Lizard. Animal Diversity Web. University of Michigan, Museum of Zoology. (accessed 22 June 2022)