Rattlesnakes are a group of venomous snakes of the genera Crotalus and Sistrurus of the subfamily Crotalinae. The scientific name Crotalus is derived from the Greek κρόταλον, meaning "castanet". The name Sistrurus is the Latinized form of the Greek word for "tail rattler" and shares its root with the ancient Egyptian musical instrument the sistrum, a type of rattle. The 36 known species of rattlesnakes have between 65 and 70 subspecies, all native to the Americas, ranging from southern Alberta, Saskatchewan, and southern British Columbia in Canada to central Argentina.
