Mexican lancehead rattlesnake
Plateau of central Mexico, from southern Zacatecas and northeastern Colima eastward to east-central Veracruz (McDiarmid et al., 1999).
Mexican Plateau from 1450 to 2600 m elevation (McDiarmid et al., 1999).
Types: None designated (McDiarmid et al., 1999).
Type-locality: "Table Land, Mexico." A proposed restriction to "Tupátaro, Guanajuato, Mexico" was made by Smith and Taylor (1950) (McDiarmid et al., 1999).
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]
The Mexican lance-headed rattlesnake or lance-headed rattlesnake (Crotalus polystictus) is a venomous pit viper species found in central Mexico. No subspecies is currently recognized.
