Crotalus scutulatus is a highly venomous pit viper species found in the deserts of the southwestern United States and central Mexico. It is perhaps best known for its potent neurotoxic-hemotoxic venom, which is considered one of the world's most potent rattlesnake venoms. Two subspecies are recognized, including the nominate subspecies described here.
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 basiliscus is a venomous pit viper species in the family Viperidae. The species is endemic to western Mexico. The specific name, basiliscus, is derived from the Greek word for king, βασιλισκος, and alludes to this snake's large size and potent venom. There are no subspecies which are recognized as being valid.
Crotalus helleri is a highly venomous pit viper subspecies found in southwestern California and south into Baja California, Mexico.
Crotalus willardi is a venomous pit viper species found in the southwestern United States and Mexico. This snake is found mainly in the "sky island" region. The IUCN reports this snake's conservation status as being of Least Concern. It is the official state reptile of Arizona.
Crotalus ruber is a venomous pit viper species found in southwestern California in the United States and Baja California in Mexico. Three subspecies are currently recognized, including the nominate subspecies described here.
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 nominate subspecies described here.
Sistrurus catenatus tergeminus is a venomous pit viper subspecies found in the southwestern plains of the United States. In some areas its range overlaps that of another subspecies, S. c. edwardsii, and intergrading of the two is not unknown.
Crotalus oreganus abyssus is a venomous pit viper subspecies found only in the U.S. states of Arizona and Utah.
Crotalus durissus is a highly venomous pit viper species found in South America. The most widely distributed member of its genus, this species poses a serious medical problem in many parts of its range. Currently, seven subspecies are recognized, including the nominate subspecies described here.
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 oreganus is a venomous pit viper species found in North America in the Baja California Peninsula, western United States, and southern interior of British Columbia.
Crotalus atrox tortugensis is a venomous pit viper subspecies found only on Tortuga Island in the Gulf of California.
The tiger rattlesnake is a highly venomous pit viper species found in the southwestern United States and northwestern Mexico. No subspecies are currently recognized. The specific name tigris, Latin for "tiger", refers to the many narrow dorsal crossbands, which create a pattern of vertical stripes when viewed from the side.
The Great Basin rattlesnake is a venomous pit viper species found in the Great Basin region of the United States.
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, including the nominate subspecies described here.
Crotalus cerastes cercobombus is a venomous pitviper subspecies found in an area that covers much of the eastern part of the Sonoran Desert in the southwestern United States and northwestern Mexico. The subspecific epithet means buzzertail.
Crotalus cerastes laterorepens, with the common name Colorado Desert sidewinder, is a venomous pitviper subspecies found in an area that centers on the Sonoran Colorado Desert in Southern California. It is also native to the Sonoran Desert in the Southwestern United States and Northwestern Mexico.
Crotalus concolor is a venomous pit viper species found in the western United States. It is a small rattlesnake known for its faded color pattern. Other common names include midget faded rattlesnake, faded rattlesnake and yellow rattlesnake.
Crotalus ruber lucasensis is a venomous pitviper subspecies found in Mexico in the Cape region of lower Baja California.
