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 Crotalus Species Crotalus horridus (Timber rattlesnake (atricaudatus)) Infraspecies Crotalus horridus atricaudatus
