The Mexican lance-headed rattlesnake
[Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. .] or lance-headed rattlesnake
[Mehrtens JM. 1987. Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. .] (''Crotalus polystictus'') is a
venomous pit viper
The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . crotaline snakes (from grc, κρόταλον ''krotalon'' castanet), or pit adders, are a subfa ...
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
found in central
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
. No subspecies is currently recognized.
Description
Adults usually grow to a total length of , although exceptionally large specimens may be as much as long.
Geographic range
The species is found on the plateau of central Mexico from southern
Zacatecas and northeastern
Colima east to east-central
Veracruz
Veracruz (), formally Veracruz de Ignacio de la Llave (), officially the Free and Sovereign State of Veracruz de Ignacio de la Llave ( es, Estado Libre y Soberano de Veracruz de Ignacio de la Llave), is one of the 31 states which, along with Me ...
. It occurs at elevations between . The
type locality given is "Table Land, Mexico", although a restriction to "Tupátaro, Guanajuanto, Mexico" was proposed by
H.M. Smith and
Taylor
Taylor, Taylors or Taylor's may refer to:
People
* Taylor (surname)
**List of people with surname Taylor
* Taylor (given name), including Tayla and Taylah
* Taylor sept, a branch of Scottish clan Cameron
* Justice Taylor (disambiguation)
Plac ...
(1950).
Conservation status
This species is classified as Least Concern on the
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...
of Threatened Species (v3.1, 2001).
Species are listed as such due to their wide distribution, presumed large population, or because they are unlikely to be declining fast enough to qualify for listing in a more threatened category. The population trend was down when assessed in 2007.
References
Further reading
*
Cope, E.D. 1865. Third contribution to the HERPETOLOGY of Tropical America. Proc. Acad. Nat. Sci. Philadelphia 17: 185-198. (''Caudisona polysticta'', pp. 191–192.)
*
Smith, H.M. and
E.H. Taylor. 1950. Type localities of Mexican reptiles and amphibians. Univ. Kansas Sci. Bull. 33: 313-380.
External links
*
Mexican Lance-headed Rattlesnakeat th
Saint Louis Zoo Accessed 18 June 2008.
{{Taxonbar, from=Q839892
polystictus
Reptiles described in 1865
Taxa named by Edward Drinker Cope