About Crotalus ravus Cope, 1865
Adults of Crotalus ravus Cope, 1865 usually reach a total length of 40 to 65 centimeters (16 to 26 inches), and some individuals can grow to more than 70 centimeters (28 inches). This species has a moderately stout body build. For the nominate subspecies C. r. ravus, key distinguishing features include particularly large, highly shape-variable parietal scales, fewer than 3 prefoveals, 21 midbody dorsal scales, 2 to 4 tail bands, and a relatively large rattle. This species is found exclusively in mountainous regions of central and southern Mexico, located west of the Isthmus of Tehuantepec. Its known range covers the southeastern Mexican Plateau highlands, spanning the states of Mexico, Morelos, Tlaxcala, Puebla, Veracruz, Oaxaca, and the Sierra Madre del Sur in Guerrero. The originally given type locality is the "Table land of Mexico"; Cochran (1961) interpreted this as referring to the "south tableland, Veracruz, Mexico". Campbell and Lamar (2004) note that this species occurs across the Mexican Plateau in temperate zones at moderate to high elevations, with an estimated vertical distribution ranging from around 1,490 meters (4,890 feet) above sea level to just over 3,000 meters (9,800 feet).
