Greater earless lizard
Encyclopedia
The greater earless lizard (Cophosaurus texanus) is a species
of earless lizard
endemic to the southwestern United States
. It is called "greater" because it grows larger than the earless lizards of the genus Holbrookia
, to which it is closely related. While C. texanus is the only species
within its genus
, it does have two subspecies
.
in the states of Texas
, New Mexico
and Arizona
; and in Mexico
in the states of Sonora
, Chihuahua, Durango
, Coahuila
, Nuevo León
, Tamaulipas
, Zacatecas
, and San Luis Potosí
.
openings, which is presumably to prevent sand
from entering their body while they dig. They are normally an overall tan
or grey
color, reflecting the color of the sand and rocks in their native habitat
for camouflage
, with black
, brown
or white
spotting. Males often develop bright blue
and green
colorations, while females tend to be duller in color, except when gravid when they turn a bright orange
color. Many have a distinctive pair of curved black bars just before the hind legs.
, basking lizard
s. In the early morning they forage
for insect
s, and then spend several hours basking in the sun, until it becomes too hot, around 111 °F (43.9 °C) at the surface, when they retreat to a burrow or rock crevice. They are oviparous.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of earless lizard
Earless lizard
Earless lizards are two genera of small lizards native to the semi-arid and grassland habitats of the southwestern United States and Mexico. The genus Cophosaurus and the genus Holbrookia are both characterized by having no external ear openings, presumably to prevent sand from entering the body as...
endemic to the southwestern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It is called "greater" because it grows larger than the earless lizards of the genus Holbrookia
Holbrookia
Holbrookia is a genus of earless lizards, known commonly as the lesser earless lizards, which contains three recognized species that are found throughout the southwestern and central United States, and northern Mexico. They are characterized by having no external ear openings, presumably to prevent...
, to which it is closely related. While C. texanus is the only species
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
within its genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, it does have two subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
.
Geographic range
It is found in the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
in the states of Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
and Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
; and in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
in the states of Sonora
Sonora
Sonora officially Estado Libre y Soberano de Sonora is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 72 municipalities; the capital city is Hermosillo....
, Chihuahua, Durango
Durango
Durango officially Estado Libre y Soberano de Durango is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. The state is located in Northwest Mexico. With a population of 1,632,934, it has Mexico's second-lowest population density, after Baja...
, Coahuila
Coahuila
Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...
, Nuevo León
Nuevo León
Nuevo León It is located in Northeastern Mexico. It is bordered by the states of Tamaulipas to the north and east, San Luis Potosí to the south, and Coahuila to the west. To the north, Nuevo León has a 15 kilometer stretch of the U.S.-Mexico border adjacent to the U.S...
, Tamaulipas
Tamaulipas
Tamaulipas officially Estado Libre y Soberano de Tamaulipas is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 43 municipalities and its capital city is Ciudad Victoria. The capital city was named after Guadalupe Victoria, the...
, Zacatecas
Zacatecas
Zacatecas officially Estado Libre y Soberano de Zacatecas is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 58 municipalities and its capital city is Zacatecas....
, and San Luis Potosí
San Luis Potosí
San Luis Potosí officially Estado Libre y Soberano de San Luis Potosí is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 58 municipalities and its capital city is San Luis Potosí....
.
Description
Greater earless lizards grow from 3-7 inches in length. They are characterized by the lack of external earEar
The ear is the organ that detects sound. It not only receives sound, but also aids in balance and body position. The ear is part of the auditory system....
openings, which is presumably to prevent sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
from entering their body while they dig. They are normally an overall tan
Tan (color)
Tan is a pale whiteish, tawny shade of white. The name is derived from tannum used in the tanning of leather.The first recorded use of tan as a shade name in English was in the year 1590....
or grey
Grey
Grey or gray is an achromatic or neutral color.Complementary colors are defined to mix to grey, either additively or subtractively, and many color models place complements opposite each other in a color wheel. To produce grey in RGB displays, the R, G, and B primary light sources are combined in...
color, reflecting the color of the sand and rocks in their native habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
for camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
, with black
Black
Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
, brown
Brown
Brown is a color term, denoting a range of composite colors produced by a mixture of orange, red, rose, or yellow with black or gray. The term is from Old English brún, in origin for any dusky or dark shade of color....
or white
White
White is a color, the perception of which is evoked by light that stimulates all three types of color sensitive cone cells in the human eye in nearly equal amounts and with high brightness compared to the surroundings. A white visual stimulation will be void of hue and grayness.White light can be...
spotting. Males often develop bright blue
Blue
Blue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 440–490 nm. It is considered one of the additive primary colours. On the HSV Colour Wheel, the complement of blue is yellow; that is, a colour corresponding to an equal...
and green
Green
Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometres. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered...
colorations, while females tend to be duller in color, except when gravid when they turn a bright orange
Orange (colour)
The colour orange occurs between red and yellow in the visible spectrum at a wavelength of about 585–620 nm, and has a hue of 30° in HSV colour space. It is numerically halfway between red and yellow in a gamma-compressed RGB colour space, the expression of which is the RGB colour wheel. The...
color. Many have a distinctive pair of curved black bars just before the hind legs.
Behavior
All earless lizards are diurnalDiurnal animal
Diurnality is a plant or animal behavior characterized by activity during the day and sleeping at night.-In animals:Animals that are not diurnal might be nocturnal or crepuscular . Many animal species are diurnal, including many mammals, insects, reptiles and birds...
, basking lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s. In the early morning they forage
Forage
Forage is plant material eaten by grazing livestock.Historically the term forage has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used more loosely to include similar plants cut for fodder and carried to the animals, especially...
for insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, and then spend several hours basking in the sun, until it becomes too hot, around 111 °F (43.9 °C) at the surface, when they retreat to a burrow or rock crevice. They are oviparous.
Subspecies
- Southwestern earless lizard, Cophosaurus texanus scitulus (PetersWilhelm PetersWilhelm Karl Hartwich Peters was a German naturalist and explorer.He was assistant to Johannes Peter Müller and later curator of the Berlin Zoological Museum. In September 1842 he travelled to Mozambique via Angola. He returned to Berlin with an enormous collection of natural history specimens...
, 1951) - Texas earless lizard, Cophosaurus texanus texanus TroschelFranz Hermann TroschelFranz Hermann Troschel was a German zoologist who was born in Spandau. He studied mathematics and natural history at the University of Berlin, and beginning in 1840 was an assistant to Martin Lichtenstein at the Humboldt Museum of Natural History in Berlin...
, 1850