Aapticheilichthys Huber, 2011 (extant flag source)
Aaptochiton Hoare & Karasawa, 2008 † (extant flag source)
Aaptochiton Hoare & Karasawa, 2008 † (habitat flag source)
Aardonyx Yates, Bonnan, Neveling, Chinsamy & Blackbeard, 2010 † (extant flag source)
Aardonyx Yates, Bonnan, Neveling, Chinsamy & Blackbeard, 2010 † (habitat flag source)
Aaveqaspis Peel & Stein, 2009 † (extant flag source)
Aaveqaspis Peel & Stein, 2009 † (habitat flag source)
Abacophrastus Will, 2011 (extant flag source)
Abagnostidae Yang & Liu, 1991 † accepted as Peronopsidae Westergard, 1936 † (extant flag source)
Abagnostidae Yang & Liu, 1991 † accepted as Peronopsidae Westergard, 1936 † (habitat flag source)
Abagnostus Yang & Liu in Yang et al., 1991 † (extant flag source)
Abagnostus Yang & Liu in Yang et al., 1991 † (habitat flag source)
Abaiba Martins & Napp, 2007 (habitat flag source)
Abauba Santos-Silva & Tavakilian, 2009 (habitat flag source)
Abaxinicephora Gorochov & Kang, 2005 (habitat flag source)
Abbrevikhosara Aristov, 2013 † (extant flag source)
Abcharis Tkoč & Ježek, 2013 (extant flag source)
Abdosetae Fu, Zhang & MacDermott, 2010 (extant flag source)
Abdosetae Fu, Zhang & MacDermott, 2010 (habitat flag source)
Abeoforma Marshall & Berbee, 2011 (extant flag source)
Aberracla Gorokhov, 2011 accepted as Leptopsis Desutter-Grandcolas, 1996 (extant flag source)
Aberratiodontus Gong, Hou & Wang, 2004 † (extant flag source)
Abes Fibiger, 2010 (habitat flag source)
Aborjinia Özdikmen, 2010 (extant flag source)
Aborjinia Özdikmen, 2010 (habitat flag source)
Abraracourcix Stroiński & Szwedo, 2011 † (extant flag source)
Abrekites Shigeta & Zakharov, 2009 † (extant flag source)
Abrekites Shigeta & Zakharov, 2009 † (habitat flag source)
Abrekopsis Kaim, 2009 † (extant flag source)
Abrekopsis Kaim, 2009 † (habitat flag source)
Abrigramma Yang, Wang, Labandeira, Shih & Ren, 2014 † (extant flag source)
Abrohadeocoleodes Tan, Ren, Shih & Yang, 2013 † (extant flag source)
Abropelecinus Feng, Shih, Ren & Liu, 2010 † (extant flag source)
Abropelecinus Feng, Shih, Ren & Liu, 2010 † (habitat flag source)
Abscondita Ballantyne, Lambkin & Fu, 2013 (extant flag source)
Absensomina Cartwright, 2010 (extant flag source)
Absensomina Cartwright, 2010 (habitat flag source)
Absurdaster Kroh, Lukeneder & Gallemí, 2014 † (extant flag source)
Abulbaspis Zhou & Zhou, 2006 † (extant flag source)
Abulbaspis Zhou & Zhou, 2006 † (habitat flag source)
Abursanema Yaghoubi, Pourjam, Pedram, Siddiqi & Atighi, 2014 (extant flag source)
Abydosaurus Chure, Britt, Whitlock & Wilson, 2010 † (extant flag source)
Abydosaurus Chure, Britt, Whitlock & Wilson, 2010 † (habitat flag source)
Abyssomelania Kaim, Jenkins, Tanabe & Kiel, 2014 † (extant flag source)
Abyssopinna Schultz & Huber, 2013 accepted as Pinna Linnaeus, 1758 (extant flag source)
Acabyara Napp & Martins, 2006 (extant flag source)
Acabyara Napp & Martins, 2006 (habitat flag source)
Acadiestheriella Kozur & Weems, 2010 † (extant flag source)
Acadiestheriella Kozur & Weems, 2010 † (habitat flag source)
Acallocheirus Bird & Bamber, 2013 (extant flag source)
Acamerobia Fan & Walter, 2011 (extant flag source)
Acamerobia Fan & Walter, 2011 (habitat flag source)
Acamptonectes Fischer, Maisch, Naish, Kosma, Liston, Joger, Krüger, Pérez, Tainsh & Appleby, 2012 † (extant flag source)
Acangaobitermes Rocha, Cancello & Cuezzo, 2011 (extant flag source)
Acanoides Sun, Marusik & Tu, 2014 (extant flag source)
Acanthaktema Pace, 2008 accepted as Hydrosmecta Thomson, 1858 (habitat flag source)
Acanthatreta Streng, 1999 † (extant flag source)
Acanthatreta Streng, 1999 † (habitat flag source)
Acanthobatesianus Wallin, Kvamme & Lin, 2012 accepted as Acanthocinus Dejean, 1821 (extant flag source)
Acanthocasuarina Taylor in Taylor, Jennings, Purcell & Austin, 2011 (extant flag source)
Acanthocasuarina Taylor in Taylor, Jennings, Purcell & Austin, 2011 (habitat flag source)
Acanthocephalonotum Petrulevičius & Popov, 2014 † (extant flag source)
Acanthocollum Opitz, 2010 (habitat flag source)
Acanthocornis Monné & Monné, 2011 accepted as Hyleoza Galileo, 1987 (extant flag source)
Acanthocornis Monné & Monné, 2011 accepted as Hyleoza Galileo, 1987 (habitat flag source)
Acantholachesilla García Aldrete, Saenz Manchola & González Obando, 2014 (extant flag source)
Acanthomichelinoceras Kröger, Klug & Mapes, 2005 † (extant flag source)
Acanthomichelinoceras Kröger, Klug & Mapes, 2005 † (habitat flag source)
Acanthoneelidus Bretfeld & Griegel, 2006 (habitat flag source)
Acanthoperla Cavalier-Smith in Cavalier-Smith & Chao, 2012 (extant flag source)
Acanthophoenicides Audo & Charbonnier, 2012 † (extant flag source)
Acanthoraculus Braun & Morris, 2009 (extant flag source)
Acanthoraculus Braun & Morris, 2009 (habitat flag source)
Acanthorhachis Martill, Del Strother & Gallien, 2014 † (extant flag source)
Acanthorota Kozur & Mostler, 2008 † (extant flag source)
Acanthorota Kozur & Mostler, 2008 † (habitat flag source)
Acanthoschizorota Kozur & Mostler, 2008 † (extant flag source)
Acanthoschizorota Kozur & Mostler, 2008 † (habitat flag source)
Acanthoscirtes Hemp, 2012 (extant flag source)
Acanthospondylus Harper, 2014 † (extant flag source)
Acanthostictoporella Ernst, 2011 † (extant flag source)
Acanthotheca Vendrasco, Kouchinsky, Porter & Fernandez, 2011 † (extant flag source)
Acanthotheca Vendrasco, Kouchinsky, Porter & Fernandez, 2011 † (habitat flag source)
Acanthotiphia Boni Bartalucci, 2011 accepted as Pseudotiphia Ashmead, 1903 (extant flag source)
Acanthotiphia Boni Bartalucci, 2011 accepted as Pseudotiphia Ashmead, 1903 (habitat flag source)
Acanthotretella Holmer & Caron, 2006 † (extant flag source)
Acanthotretella Holmer & Caron, 2006 † (habitat flag source)
Acareprosopon Klompmaker, 2013 † (extant flag source)
Acaricesa Koçak & Kemal, 2008 (habitat flag source)
Acaricis Beard & Gerson, 2009 (habitat flag source)
Acarnana Emeljanov, 2012 accepted as Acarna Stål, 1863 (extant flag source)
Acatinga Santos-Silva, Martins & Clarke, 2010 (habitat flag source)
Acauda Whipps, 2011 (extant flag source)
Acavomonas Tikhonenkov, Janouškovec, Mylnikov, Mikhailov, Simdyanov, Aleoshin & Keeling, 2014 (extant flag source)
Acephalus Mandal & Ray, 2013 (extant flag source)
Acerbitas Özdikmen, 2006 (habitat flag source)
Acerobiella Gattolliat, 2012 (extant flag source)
Acerplica Waterhouse, 2008 † (extant flag source)
Acetyphlops Hoser, 2012 accepted as Typhlops Oppel, 1811 (extant flag source)
Achaemenothrombiidae Saboori, Wohltmann & Hakimitabar, 2010 (extant flag source)