Massasauga

Species of Sistrurus are found in Canada, the Western, Southern, and Midwestern United States, and isolated populations in southern and eastern Mexico.

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

{|cellspacing=0 cellpadding=2 border=1 style="border-collapse: collapse;" !bgcolor="#f0f0f0"|Image !bgcolor="#f0f0f0"|Species !bgcolor="#f0f0f0"|Taxon author !bgcolor="#f0f0f0"|Subsp. !bgcolor="#f0f0f0"|Common name !bgcolor="#f0f0f0"|Geographic range |- | |S. catenatus |(Rafinesque, 1818) |align="center"| - |eastern massasauga |style="width:45%"|It is found in the Great Lakes region from southeastern Ontario (Canada) and central and western New York west to Iowa. It occurs in various habitats ranging from swamps and marshes to grasslands, usually below altitude. |- | |S. miliarius T |(Linnaeus, 1766) |align="center"|3 |pygmy rattlesnake |In the Southeastern United States from eastern and southern North Carolina southward through peninsular Florida and westward to Oklahoma and East Texas. It occurs in flatwoods, sandhills, mixed forests, and floodplains, and around marshes and lakes. |- | |S. tergeminus |(Say, 1823) |align="center"|2 |western massasauga |Found throughout the Great Plains and southwestern states (from Kansas to Arizona) into disjunct populations in Mexico (Tamaulipas, southern Nuevo León, north-central Coahuila, and Samalayuca, Chihuahua). It inhabits grasslands, rocky hillsides, and woodland edges. |} T) Type species.