| Crotalus ravus | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Serpentes |
| Family: | Viperidae |
| Genus: | Crotalus |
| Species: | C. ravus |
| Binomial name | |
| Crotalus ravus (Cope, 1865) | |
 | |
| Synonyms [2] | |
Crotalus ravus, commonly known as the Mexican pigmy rattlesnake [3] or Mexican pygmy rattlesnake, [4] is a venomous pit viper species, found only in Mexico. Three subspecies are currently recognized. [5]
A study using mitochondrial DNA strongly suggests that C. ravus is part of a species complex including Crotalus triseriatus , Crotalus pusillus , Crotalus aquilus , and Crotalus lepidus . [6] This study also confirmed strong genetic differentiation among the three subspecies aligning with geographic barriers. A follow-up study using seven nuclear markers places S. ravus basal to all other members of the species complex. [7]
| Subspecies [5] | Taxon author [5] | Common name [8] | Geographic range [4] |
|---|---|---|---|
| C. r. brunneus | Harris & Simmons, 1977 | Oaxacan pygmy rattlesnake | Mexico in the highlands of Oaxaca. |
| C. r. exiguus | Campbell & Armstrong, 1979 | Guerreran pygmy rattlesnake | Mexico in the Sierra Madre del Sur of central Guerrero. |
| C. r. ravus | (Cope, 1865) | Central Mexican pygmy rattlesnake | Mexico in the Altiplanicie Meridional, including the states of México, Morelos, Tlaxcala, Puebla, and Veracruz. |
Adults of this species usually grow to a length of 40–65 centimetres (16–26 in), but may reach more than 70 cm (28 in). They are moderately stout in build. [4]
The distinguishing characteristics for the nominate subspecies C. r. ravus include parietal scales that are highly variable in shape and particularly large, less than 3 prefoveals, 21 midbody dorsal scales, 2–4 tail bands and a relatively large rattle. [4]
Found only in Mexico in the mountains in the center and south of the country, west of the Isthmus of Tehuantepec. Its range includes the southeastern part of the Mexican Plateau in the highlands of Mexico, Morelos, Tlaxcala, Puebla, Veracruz, Oaxaca, and the Sierra Madre del Sur in Guerrero. The type locality given is the "Table land of Mexico." Cochran (1961) interpreted this to be the "south tableland, Veracruz, Mexico." [2]
Campbell and Lamar (2004) [4] describe this species as being found across the Mexican Plateau in the temperate regions of moderate to high elevations. They estimate the vertical distribution to be from about 1,490 metres (4,890 ft) above sea level to a little over 3,000 m (9,800 ft) altitude. [4]
Although being listed as of "Least Concern" by the IUCN, C. ravus was listed as "threatened" by the Mexican government in 2010. [9]
Crotalus lepidus is a venomous pit viper species found in the southwestern United States and northern central Mexico. Four subspecies are currently recognized, including the nominate subspecies described here.
Crotalus basiliscus, known as the Mexican west coast rattlesnake, Mexican green rattler, and also by other names, is a species of pit viper in the family Viperidae. The species is endemic to western Mexico. Like all other pit vipers, it is venomous. The specific name, basiliscus, is derived from the Greek word for king, βασιλισκος, and alludes to this snake's large size and potent venom. No subspecies are currently recognized.
Crotalus mitchellii is a venomous pit viper species in the family Viperidae. The species is endemic to the Southwestern United States and adjacent northern Mexico. The species was named in honor of Silas Weir Mitchell (1829–1914), an American medical doctor who also studied rattlesnake venoms. Five subspecies are currently recognized, including the nominate subspecies described here.
Crotalus viridis nuntius is a venomous pit viper subspecies native primarily to the desert plateau of the northeastern portion of the American state of Arizona, but also ranges into northwestern New Mexico. Named for the Native American Hopi tribe, which inhabits the region, its range overlaps that of the nominate subspecies and some interbreeding is believed to occur. The taxonomy of the C. viridis group is a matter of debate, many considering the various subspecies to be nothing more than locality variations.
Crotalus simus is a venomous pit viper species found in Mexico and Central America. The specific epithet is Latin for "flat-nosed", likely because its head is blunt compared with lanceheads (Bothrops). Three subspecies are recognized, including the nominate subspecies described here.
Crotalus atrox tortugensis is a venomous pit viper subspecies found only on Tortuga Island in the Gulf of California.
Crotalus intermedius is a pit viper species found in central and southern Mexico. Like all other pit vipers, it is venomous. Three subspecies are currently recognized, including the nominate subspecies described here.
Crotalus intermedius omiltemanus is a venomous pitviper subspecies found in Mexico in the state of Guerrero.
Crotalus intermedius gloydi is a subspecies of venomous pitviper in the family Viperidae. The subspecies is endemic to Mexico in the states of Oaxaca and Puebla.
Crotalus pricei is a species of venomous snake, a pit viper in the family Viperidae. The species is endemic to the southwestern United States and northern Mexico. Two subspecies are recognized.
Crotalus lannomi, known commonly as the Autlán rattlesnake, is a species of venomous snake, a pit viper in the family Viperidae. The species is endemic to southwestern Mexico. There are no subspecies that are recognized as being valid.
The Mexican lance-headed rattlesnake or lance-headed rattlesnake is a venomous pit viper species found in central Mexico. No subspecies is currently recognized.
Crotalus pusillus is a venomous pit viper species found in west-central Mexico. No subspecies are currently recognized.
Crotalus stejnegeri, commonly known as the Sinaloan long-tailed rattlesnake or just long-tailed rattlesnake, is a venomous pit viper species in the family Viperidae. The species is native to western Mexico. There are no recognized subspecies.
Crotalus transversus is a venomous pit viper species found in central Mexico, known from less than 20 specimens. No subspecies are currently recognized.
Crotalus triseriatus is a venomous pit viper species found in Mexico. Two subspecies are currently recognized, including the nominate subspecies described here.
Crotalus totonacus is a venomous pit viper species found in northeastern Mexico. No subspecies are currently recognized.
Crotalus angelensis, or the Ángel de la Guarda Island speckled rattlesnake, is a pitviper species endemic to Isla Ángel de la Guarda in the Gulf of California, Mexico. Like all other pitvipers, it is venomous. It is sometimes treated as a subspecies of Crotalus mitchellii.
Crotalus lorenzoensis is a species of pitviper, a venomous snake in the subfamily Crotalinae of the family Viperidae. The species is endemic to San Lorenzo Sur Island, Mexico.
Crotalus ruber lucasensis is a venomous pitviper subspecies found in Mexico in the Cape region of lower Baja California.
