Crotalus is a genus of pit vipers, commonly known as rattlesnakes or rattlers, in the family Viperidae. The genus is found only in the Americas from southern Canada to northern Argentina. The generic name Crotalus is derived from the Greek word κρόταλονkrótalοn, which means "rattle" or "castanet", and refers to the rattle on the end of the tail, which makes this group so distinctive. As of July 2023, 44 to 53 species are recognized as valid.
Crotalus scutulatus is known commonly as the Mohave Rattlesnake. Other common English names include Mojave Rattlesnake and, referring specifically to the nominate (northern) subspecies: Northern Mohave Rattlesnake and Mojave Green Rattlesnake, the latter name commonly shortened to the more colloquial “Mojave green”. Campbell and Lamar (2004) supported the English name “Mohave (Mojave) rattlesnake” with some reluctance because so little of the snake’s range lies within the Mojave Desert.
The black-tailed rattlesnake is a venomous pit viper species found in the southwestern United States and Mexico. Four subspecies are currently recognized, including the nominate subspecies described here.
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 helleri or Crotalus oreganus helleri, also known commonly as the Southern Pacific rattlesnake, the black diamond rattlesnake, and by several other common names, is a pit viper species or subspecies found in southwestern California and south into Baja California, Mexico, that is known for its regional variety of dangerous venom types. It is sometimes considered a subspecies of Crotalus oreganus.
The western diamondback rattlesnake or Texas diamond-back is a rattlesnake species and member of the viper family, found in the southwestern United States and Mexico. Like all other rattlesnakes and all other vipers, it is venomous. It is likely responsible for the majority of snakebite fatalities in northern Mexico and the greatest number of snakebites in the U.S. No subspecies are currently recognized.
Crotalus viridis is a venomous pit viper species native to the western United States, southwestern Canada, and northern Mexico. Currently, two subspecies are recognized, including the prairie rattlesnake, the nominate subspecies, and the Hopi rattlesnake.
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.
The Santa Catalina rattlesnake is a species of pit viper endemic to Isla Santa Catalina in the Gulf of California just off the east coast of the state of Baja California Sur, Mexico. Like all other pit vipers, it is venomous. No subspecies are currently recognized. A relatively small and slender species, its most distinctive characteristic is that it lacks a rattle. They are also a generally nocturnal species. Though the species is classified as Critically Endangered on the IUCN Red List, there are few efforts for the snake's conservation.
Crotalus ravus, commonly known as the Mexican pigmy rattlesnake or Mexican pygmy rattlesnake, is a venomous pit viper species, found only in Mexico. Three subspecies are currently recognized.
Crotalus durissus, known as the South American rattlesnake, tropical rattlesnake, and by other names, is a highly venomous pit viper species found in South America. It is the most widely distributed member of its genus. Currently, seven 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.
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 triseriatus is a venomous pit viper species found in Mexico. Two subspecies are currently recognized, including the nominate subspecies described here.
Crotalus concolor, commonly known as the midget faded rattlesnake, faded rattlesnake, and yellow rattlesnake, is a pit viper species found in the western United States. It is a small rattlesnake known for its faded color pattern. Like all other pit vipers, it is venomous.
Basaseachic Falls National Park is a national park located in the western side of the state of Chihuahua in the heart of the Sierra Madre Occidental mountain range. The park is named after Basaseachic Falls the second tallest waterfall in Mexico with a height of 246 meters (853 ft). Basaseachic Falls empties into Candameña Canyon which was carved by the Basaseachic River over millions of years. The park is known for its pine-oak forest, rock formations, and scenic views from high cliffs. Cliffs in the park reach an impressive height of 1,640 meters (5,380 ft).
Crotalus molossus nigrescens, or the Mexican black-tailed rattlesnake, is a subspecies of black-tailed rattlesnake from Southern America. The name nigrescens comes from the Latin word "to become dark in colour". As with all rattlesnakes, it is venomous.
