Kingdom Animalia (animals) Eumetazoa (metazoans) Bilateria (bilaterally symmetrical animals) Deuterostomia (deuterostomes) Phylum Chordata (chordates) Craniata (craniates) Subphylum Vertebrata (vertebrates) Superclass Gnathostomata (jawed vertebrates) Euteleostomi (bony vertebrates) Class Sarcopterygii (lobe-finned fishes and terrestrial vertebrates) Tetrapoda (tetrapods) Amniota (amniotes) Class Reptilia (turtles, snakes, lizards, and relatives) Order Squamata Family Viperidae Genus Sistrurus Species Sistrurus catenatus (Massasauga) Species Sistrurus miliarius (Pigmy Rattlesnake) Species Sistrurus ravus (Mexican Massasauga)
