| Crotalus polystictus | |
|---|---|
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Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Serpentes |
| Family: | Viperidae |
| Genus: | Crotalus |
| Species: | C. polystictus
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| Binomial name | |
| Crotalus polystictus (Cope, 1865)
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| Synonyms | |
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The Mexican lance-headed rattlesnake[3] or lance-headed rattlesnake[4] (Crotalus polystictus) is a venomous pit viper species found in central Mexico. No subspecies is currently recognized.[5]
Adults usually grow to a total length of 60 to 70 cm (24 to 28 in), although exceptionally large specimens may be as much as 100 cm (39 in) long.[3]
The species is found on the plateau of central Mexico from southern Zacatecas and northeastern Colima east to east-central Veracruz. It occurs at elevations between 1,450 and 2,600 m (4,760 and 8,530 ft). The type locality given is "Table Land, Mexico", although a restriction to "Tupátaro, Guanajuanto, Mexico" was proposed by H.M. Smith and Taylor (1950).[2]
This species is classified as Least Concern on the IUCN Red List of Threatened Species (v3.1, 2001).[1] 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.[6]
