''Holbrookia propinqua'', commonly known as the keeled earless lizard, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of phrynosomatid

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

Description

The dorsal scales are small, pointed, and keeled, as the common name implies. The lateral scales are similar but smaller. The ventral scales, which are flat and smooth, are 3-4 times larger than the dorsal scales. Adults may attain snout to vent length (SVL), total length. Smith, H.M. and E.D. Brodie, Jr. 1982. ''Reptiles of North America, A Guide to Field Identification''. Golden Press. New York. pp. 128-129.

Geographic range and habitat

''Holbrookia propinqua'' occurs in the

Tamaulipan mezquital The Tamaulipan mezquital (), also known as the Brush Country, is a deserts and xeric shrublands ecoregion in the Southern United States and northeastern Mexico. It covers an area of , encompassing a portion of the Gulf Coastal Plain in southern T ...

ecoregion where it is known from various vegetation zones in south Texas, including mixed oak forest, mesquite brush-lands, cleared fields, coastal prairie, and grasslands, although always where bands of

Tertiary Tertiary (from Latin, meaning 'third' or 'of the third degree/order..') may refer to: * Tertiary period, an obsolete geologic period spanning from 66 to 2.6 million years ago * Tertiary (chemistry), a term describing bonding patterns in organic ch ...

sand outcrops or sandy stream-side deposits are found. It is perhaps most common in the loose and shifting sands of beaches,

barrier islands Barrier islands are a coastal landform, a type of dune system and sand island, where an area of sand has been formed by wave and tidal action parallel to the mainland coast. They usually occur in chains, consisting of anything from a few is ...

, and the Coastal Sand Plain of Southern Texas. It also ranges into northeast

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

but it is highly restricted to the narrow zone of sand dunes of the coastal beaches, peninsulas, and barrier islands of

Tamaulipas Tamaulipas, officially the Free and Sovereign State of Tamaulipas, is a state in Mexico; one of the 31 states which, along with Mexico City, comprise the 32 federal entities of Mexico. It is divided into 43 municipalities. It is located in nor ...

and southward to the vicinity of

Veracruz Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...

.Axtell, Ralph W. 1983. ''Holbrookia propinqua''. Catalogue of American Amphibians and Reptiles. Society for the Study of Amphibians and Reptiles. 341:1-2 pp.Axtell, Ralph W. 1998. ''Holbrookia propinqua''. Interpretive Atlas of Texas Lizards, No. 19. Southern Illinois University at Edwardsville, Edwardsville, Illinois. 1-14 pp.

Subspecies

There are three recognized

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of ''Holbrookia propinqua'': *northern keeled earless lizard, ''

Holbrookia propinqua propinqua ''Holbrookia'' is a genus of earless lizards, known commonly as the lesser earless lizards, in the Family (biology), family Phrynosomatidae. The genus contains six recognized species, which are found throughout the Southwestern United States, ...

'' Baird & Girard, 1852 *southern keeled earless lizard, '' Holbrookia propinqua piperata'' H.M. Smith &

Burger Burger or Burgers may refer to: Food and drink Foods * Hamburger, a food consisting of one or more cooked beef patties, placed inside a sliced bread roll or bun roll. ** Cheeseburger, a hamburger with added cheese(s) * Ground beef, minced bee ...

, 1950 *Stone's keeled earless lizard, '' Holbrookia propinqua stonei''

Harper Harper may refer to: Names * Harper (name), a surname and given name and place names, for example: Harper Islands, Nunavut. Places ;in Canada * Harper Islands, Nunavut * Harper, Prince Edward Island ;In the United States *Harper, former name ...

, 1932

References

* Holbrookia Reptiles of Mexico Reptiles of the United States Fauna of the Southwestern United States Fauna of the Rio Grande valleys Reptiles described in 1852 Taxa named by Spencer Fullerton Baird {{Phrynosomatidae-stub