Squamata Oppel 1811 [Gauthier, Estes & de Queiroz 1988], nom. cl. inval. see Order Squamata Oppel, 1811
   Episquamata Vidal & Hedges, 2005
     Toxicofera Vidal & Hedges, 2005
       Serpentes see Suborder Serpentes Linnaeus, 1758
         Family Viperidae Oppel, 1811 - vipers and pit vipers
           Subfamily Crotalinae Oppel, 1811 - pit vipers
             01 Genus Agkistrodon de Beauvois, 1799
             02 Genus Atropoides Werman, 1992
             03 Genus Bothriechis Peters, 1859
             04 Genus Bothriopsis Peters, 1861 see Genus Bothrops Wagler, 1824
             05 Genus Bothrocophias Gutberlet & Campbell, 2001
             06 Genus Bothropoides Fenwick, Gutberlet Jr., Evans & Parkinson, 2009 see Genus Bothrops Wagler, 1824
             07 Genus Bothrops Wagler, 1824
             08 Genus Calloselasma Cope, 1859
             09 Genus Cerrophidion Campbell & Lamar, 1992
             10 Genus Crotalus Linnaeus, 1758
             11 Genus Deinagkistrodon Gloyd, 1979
             12 Genus Garthius Malhotra & Thorpe, 2004
             13 Genus Gloydius Hoge & Romano-Hoge, 1981
             14 Genus Hypnale Fitzinger, 1843
             15 Genus Lachesis Daudin, 1803
             16 Genus Mixcoatlus Jadin, Smith & Campbell, 2011
             17 Genus Ophryacus Cope, 1887
             18 Genus Ovophis Burger, 1988
             19 Genus Porthidium Cope, 1871
             20 Genus Protobothrops Hoge & Romano-Hoge, 1983
             21 Genus Rhinocerophis Garman, 1881 see Genus Bothrops Wagler, 1824
             22 Genus Sistrurus Garman, 1883
             23 Genus Trimeresurus Lacepède, 1804
             24 Genus Tropidolaemus Wagler, 1830