Sistrurus

Common names: ground rattlesnakes, pigmy rattlesnakes, massasaugas.

Sistrurus is a genus of venomous pitvipers found in Canada, the United States and Mexico. Three species are currently recognized.

Description

Sistrurus species differ from the larger rattlesnakes of the genus Crotalus in a number of ways. They are smaller in size, but also their scalation is different: Sistrurus species have nine large head plates (same as Agkistrodon), whereas with Crotalus (and almost all other viperids) the head is mostly covered with a large number of smaller scales. Sistrurus species have a relatively small rattle that produces more of a high-pitched, buzzing sound than a rattle, like Crotalus.

Geographic range

Found in southeastern Canada, the eastern and northwestern United States, as well as isolated populations in northern and central Mexico.

Venom

Although bites from Sistrurus species are regarded as less dangerous to humans, primarily due to the lower venom yield, every venomous snake bite should be considered serious and prompt medical treatment should always be sought.

Species

Species	Taxon author	Subsp.*	Common name	Geographic range
S. catenatus	(Rafinesque, 1818)	2	Massasauga	North America from southeastern Ontario (Canada) and western New York State southwest to southeastern Arizona (USA) and northern Tamaulipas (Mexico). In Mexico, isolated population exist in southern Nuevo León and north-central Coahuila. It occurs in various habitats ranging from swamps and marshes to grasslands, usually below 1500 m altitude.
S. miliarius^T	(Linnaeus, 1766)	2	Pigmy rattlesnake	The southeastern United States from eastern and southern North Carolina southward through peninsular Florida and westward to Oklahoma and eastern Texas. It occurs in flatwoods, sandhills, mixed forests, flood plains and around marshes and lakes.
S. ravus	(Cope, 1865)	2	Mexican pigmy rattlesnake	The mountains of central and southern Mexico, west of the Isthmus of Tehuantepec, in the southeastern part of the Mexican Plateau, in the highlands of Morelos, Tlaxcala, Puebla, Veracruz, Oaxaca and the Sierra Madre del Sur in Guerrero.