Opinions from H. B. Whittington et al. 1997
- 'Abadiella belongs to Abadiellidae'
- 'Abadiellidae belongs to Redlichiida'
- 'Abakolia belongs to Weymouthiidae'
- 'Acadagnostus belongs to Diplagnostidae'
- 'Acadoparadoxides belongs to Paradoxididae'
- 'Acastidae belongs to Phacopida'
- 'Acidiscus belongs to Weymouthiidae'
- 'Acimetopus belongs to Weymouthiidae'
- 'Acmarhacis is a misspelling of Acmarhachis'
- 'Acmarhachis belongs to Agnostidae'
- 'Acrocephalitidae belongs to Ptychopariida'
- 'Aculeodiscus is a subjective synonym of Dawsonia'
- 'Agnostardis belongs to Agnostidae'
- 'Agnostida belongs to Trilobita'
- 'Agnostidae belongs to Agnostida'
- 'Agnostotes belongs to Diplagnostidae'
- 'Agnostus belongs to Agnostidae'
- 'Agraulidae belongs to Ptychopariida'
- 'Alaskadiscus belongs to Yukoniidae'
- 'Alsataspididae belongs to Asaphida'
- 'Ammagnostus belongs to Agnostidae'
- 'Analox belongs to Weymouthiidae'
- 'Andalusiana belongs to Holmiidae'
- 'Anglagnostus belongs to Metagnostidae'
- 'Anomocaridae belongs to Asaphida'
- 'Anopolenus belongs to Centropleuridae'
- 'Archaeaspididae belongs to Redlichiida'
- 'Archaeaspis belongs to Archaeaspididae'
- 'Arcuolenellus belongs to Olenellidae'
- 'Arthrorhachis belongs to Metagnostidae'
- 'Asaphidae belongs to Asaphida'
- 'Asaphiscidae belongs to Ptychopariida'
- 'Aspidagnostus belongs to Clavagnostidae'
- 'Aulacopleuridae belongs to Proetida'
- 'Balcoracania belongs to Emuellidae'
- 'Baltagnostus belongs to Diplagnostidae'
- 'Bathycheilidae belongs to Phacopida'
- 'Bathydiscus belongs to Weymouthiidae'
- 'Bathyuridae belongs to Proetida'
- 'Biceratops belongs to Olenellidae'
- 'Bohemillidae belongs to Asaphida'
- 'Bolaspididae belongs to Ptychopariida'
- 'Bolbolenellus belongs to Olenellidae'
- 'Bolboparia belongs to Weymouthiidae'
- 'Bondonella belongs to Neltneriidae'
- 'Bradyfallotaspis belongs to Archaeaspididae'
- 'Bristolia belongs to Olenellidae'
- 'Bulaiaspis belongs to Chengkouaspidae'
- 'Callavia belongs to Holmiidae'
- 'Calmoniidae belongs to Phacopida'
- 'Calodiscidae belongs to Agnostida'
- 'Calodiscus belongs to Calodiscidae'
- 'Calymenidae belongs to Phacopida'
- 'Cambropallas belongs to Holmiidae'
- 'Catillicephalidae belongs to Ptychopariida'
- 'Cedariidae belongs to Ptychopariida'
- 'Centropleura belongs to Centropleuridae'
- 'Centropleuridae belongs to Redlichiida'
- 'Cephalopyge belongs to Weymouthiidae'
- 'Ceratopygidae belongs to Asaphida'
- 'Cheilocephalidae belongs to Corynexochida'
- 'Cheiruridae belongs to Phacopida'
- 'Chengkouaspidae belongs to Redlichiida'
- 'Choubertella belongs to Fallotaspididae'
- 'Clarella belongs to Centropleuridae'
- 'Clavagnostidae belongs to Agnostida'
- 'Clavagnostus belongs to Clavagnostidae'
- 'Cobboldites belongs to Weymouthiidae'
- 'Condylopyge belongs to Condylopygidae'
- 'Condylopygidae belongs to Agnostida'
- 'Connagnostus belongs to Agnostidae'
- 'Conocoryphidae belongs to Ptychopariida'
- 'Corrugatagnostus belongs to Metagnostidae'
- 'Corynexochidae belongs to Corynexochida'
- 'Costadiscus is a subjective synonym of Abakolia'
- 'Cotalagnostus belongs to Spinagnostidae'
- 'Crepicephalidae belongs to Ptychopariida'
- 'Cyclopygidae belongs to Asaphida'
- 'Daguinaspis belongs to Fallotaspididae'
- 'Dalmanitidae belongs to Phacopida'
- 'Damesellidae belongs to Lichida'
- 'Dawsonia belongs to Eodiscidae'
- 'Delgadella belongs to Hebediscidae'
- 'Denagnostus belongs to Diplagnostidae'
- 'Diceratocephalidae belongs to Ptychopariida'
- 'Dimeropygidae belongs to Proetida'
- 'Dinesidae belongs to Corynexochida'
- 'Dionididae belongs to Asaphida'
- 'Diplagnostidae belongs to Agnostida'
- 'Diplagnostus belongs to Diplagnostidae'
- 'Diplorrhina belongs to Peronopsidae'
- 'Dolerolenidae belongs to Redlichiida'
- 'Dolerolenus belongs to Dolerolenidae'
- 'Dolichometopidae belongs to Corynexochida'
- 'Doryagnostus belongs to Spinagnostidae'
- 'Dorypygidae belongs to Corynexochida'
- 'Eccaparadoxides belongs to Paradoxididae'
- 'Edelsteinaspididae belongs to Corynexochida'
- 'Ekwipagetia belongs to Yukoniidae'
- 'Elganellus belongs to Redlichiida'
- 'Ellipsocephalidae belongs to Ptychopariida'
- 'Elliptocephala is corrected as Elliptocephalus and belongs to Holmiidae'
- 'Elviniidae belongs to Ptychopariida'
- 'Emuellidae belongs to Redlichiida'
- 'Emuelloidea belongs to Redlichiina'
- 'Encrinuridae belongs to Phacopida'
- 'Eoagnostus belongs to Spinagnostidae'
- 'Eodiscidae belongs to Agnostida'
- 'Eodiscus belongs to Eodiscidae'
- 'Eodiscus (Serrodiscus) was reranked as Serrodiscus and belongs to Weymouthiidae'
- 'Eofallotaspis belongs to Fallotaspididae'
- 'Eops belongs to Saukiandidae'
- 'Eoredlichia belongs to Redlichiidae'
- 'Esmeraldina belongs to Holmiidae'
- 'Eurekiidae belongs to Asaphida'
- 'Fallagnostus is a subjective synonym of Condylopyge'
- 'Fallotaspididae belongs to Redlichiida'
- 'Fallotaspis belongs to Fallotaspididae'
- 'Fremontella belongs to Olenellidae'
- 'Gabriellus belongs to Olenellidae'
- 'Galbagnostus belongs to Metagnostidae'
- 'Geragnostella belongs to Metagnostidae'
- 'Geragnostus belongs to Metagnostidae'
- 'Geraldinella belongs to Archaeaspididae'
- 'Girvanagnostus is a subjective synonym of Arthrorhachis'
- 'Glyptagnostus belongs to Agnostidae'
- 'Goniagnostus belongs to Ptychagnostidae'
- 'Gymnagnostus belongs to Agnostidae'
- 'Hadragnostus belongs to Agnostidae'
- 'Hebediscidae belongs to Agnostida'
- 'Hebediscus belongs to Hebediscidae'
- 'Holmia belongs to Holmiidae'
- 'Holmiella belongs to Holmiidae'
- 'Holmiidae belongs to Redlichiida'
- 'Holotrachelidae belongs to Proetida'
- 'Homagnostoides belongs to Metagnostidae'
- 'Homalonotidae belongs to Phacopida'
- 'Hungaiidae belongs to Asaphida'
- 'Hupeidiscus is a subjective synonym of Tsunyidiscus'
- 'Hydrocephalus belongs to Paradoxididae'
- 'Hypagnostus belongs to Spinagnostidae'
- 'Hyperagnostus is a subjective synonym of Neoagnostus'
- 'Idahoiidae belongs to Asaphida'
- 'Illaenidae belongs to Corynexochida'
- 'Illaenuridae belongs to Corynexochida'
- 'Inella belongs to Chengkouaspidae'
- 'Innitagnostus belongs to Agnostidae'
- 'Iyouella belongs to Holmiidae'
- 'Jakutidae belongs to Corynexochida'
- 'Judomia belongs to Judomiidae'
- 'Judomiidae belongs to Redlichiida'
- 'Kaolishaniidae belongs to Corynexochida'
- 'Kerberodiscus is a subjective synonym of Leptochilodiscus'
- 'Kingstoniidae belongs to Ptychopariida'
- 'Kjerulfia belongs to Holmiidae'
- 'Kormagnostus belongs to Agnostidae'
- 'Kuanyangia belongs to Redlichiidae'
- 'Ladadiscus is a subjective synonym of Mallagnostus'
- 'Laudonia belongs to Olenellidae'
- 'Leiostegiidae belongs to Corynexochida'
- 'Lejopyge belongs to Ptychagnostidae'
- 'Lemdadella belongs to Redlichiidae'
- 'Leptochilodiscus belongs to Weymouthiidae'
- 'Lichakephalidae belongs to Lichida'
- 'Lichidae belongs to Lichida'
- 'Linguagnostus belongs to Diplagnostidae'
- 'Liostracinidae belongs to Asaphida'
- 'Lisaniidae belongs to Ptychopariida'
- 'Lisogoragnostus belongs to Phalacromidae'
- 'Litagnostus belongs to Diplagnostidae'
- 'Lonchocephalidae belongs to Ptychopariida'
- 'Lorenzellidae belongs to Ptychopariida'
- 'Lotagnostus belongs to Agnostidae'
- 'Luhops belongs to Centropleuridae'
- 'Macannaia belongs to Eodiscidae'
- 'Mallagnostus belongs to Weymouthiidae'
- 'Marjumiidae belongs to Ptychopariida'
- 'Menneraspidae belongs to Redlichiida'
- 'Menneraspis belongs to Menneraspidae'
- 'Menomoniidae belongs to Ptychopariida'
- 'Metagnostidae belongs to Agnostida'
- 'Micragnostus belongs to Agnostidae'
- 'Mummaspis belongs to Olenellidae'
- 'Nahannagnostus belongs to Diplagnostidae'
- 'Neltneria belongs to Neltneriidae'
- 'Neltneriidae belongs to Redlichiida'
- 'Neoagnostus belongs to Diplagnostidae'
- 'Neocobboldia belongs to Calodiscidae'
- 'Neopagetina belongs to Hebediscidae'
- 'Nephrolenellus belongs to Olenellidae'
- 'Neptunagnostella is a subjective synonym of Geragnostus'
- 'Nevadella belongs to Nevadiidae'
- 'Nevadia belongs to Nevadiidae'
- 'Nevadiidae belongs to Redlichiida'
- 'Nileidae belongs to Asaphida'
- 'Norwoodiidae belongs to Ptychopariida'
- 'Odontopleuridae belongs to Lichida'
- 'Oedorhachis belongs to Diplagnostidae'
- 'Oidalagnostus belongs to Diplagnostidae'
- 'Olenellida is a subjective synonym of Olenellina'
- 'Olenellidae belongs to Redlichiida'
- 'Olenellus belongs to Olenellidae'
- 'Olenidae belongs to Ptychopariida'
- 'Oncagnostus belongs to Agnostidae'
- 'Onymagnostus belongs to Ptychagnostidae'
- 'Opsidiscus belongs to Eodiscidae'
- 'Oryctocephalidae belongs to Corynexochida'
- 'Paedumias is a misspelling of Paedeumias'
- 'Pagetia belongs to Eodiscidae'
- 'Pagetides belongs to Eodiscidae'
- 'Pagetiellus is a subjective synonym of Delgadella'
- 'Pagodiidae belongs to Corynexochida'
- 'Palmettaspis belongs to Holmiidae'
- 'Papyriaspididae belongs to Ptychopariida'
- 'Parabolinoididae belongs to Asaphida'
- 'Paradoxididae belongs to Redlichiida'
- 'Parafallotaspis belongs to Fallotaspididae'
- 'Paranevadella belongs to Judomiidae'
- 'Peachella belongs to Olenellidae'
- 'Pentagnostus belongs to Ptychagnostidae'
- 'Peratagnostus belongs to Spinagnostidae'
- 'Peronopsella belongs to Peronopsidae'
- 'Peronopsidae belongs to Agnostida'
- 'Peronopsis belongs to Peronopsidae'
- 'Perrector belongs to Saukiandidae'
- 'Phacopidae belongs to Phacopida'
- 'Phacops (Nephranops) incisus dillanus is recombined as Nephranops dillanus' according to Richter and Richter 1926
- 'Phalacroma belongs to Phalacromidae'
- 'Phalacromidae belongs to Agnostida'
- 'Phoidagnostoides is a subjective synonym of Leiagnostus'
- 'Pilekiidae belongs to Phacopida'
- 'Platagnostus is a subjective synonym of Phalacroma'
- 'Plethopeltidae belongs to Ptychopariida'
- 'Pleuroctenium belongs to Condylopygidae'
- 'Pliomeridae belongs to Phacopida'
- 'Poletaevella belongs to Redlichiida'
- 'Proagnostus belongs to Agnostidae'
- 'Proasaphiscidae belongs to Ptychopariida'
- 'Profallotaspis belongs to Fallotaspididae'
- 'Prosopiscidae belongs to Phacopida'
- 'Pseudagnostus belongs to Diplagnostidae'
- 'Pseudoperonopsis belongs to Spinagnostidae'
- 'Pseudorhaptagnostus is a subjective synonym of Neoagnostus'
- 'Pterocephaliidae belongs to Asaphida'
- 'Pterygometopidae belongs to Phacopida'
- 'Ptychagnostidae belongs to Agnostida'
- 'Ptychagnostus belongs to Ptychagnostidae'
- 'Ptychaspididae belongs to Asaphida'
- 'Ptychopariidae belongs to Ptychopariida'
- 'Quadrahomagnostus belongs to Agnostidae'
- 'Raphiophoridae belongs to Asaphida'
- 'Raymondinidae belongs to Ptychopariida'
- 'Redlichia belongs to Redlichiinae'
- 'Redlichiida belongs to Trilobita'
- 'Redlichiidae belongs to Redlichiida'
- 'Redlichiinae belongs to Redlichiidae'
- 'Redlichina belongs to Redlichinidae'
- 'Redlichinidae belongs to Redlichiida'
- 'Redlichioidea belongs to Redlichiina'
- 'Rejkocephalus is a subjective synonym of Hydrocephalus'
- 'Remopleurididae belongs to Asaphida'
- 'Rhyssometopidae belongs to Asaphida'
- 'Runcinodiscus belongs to Weymouthiidae'
- 'Sajanaspis belongs to Redlichinidae'
- 'Saukianda belongs to Saukiandidae'
- 'Saukiandidae belongs to Redlichiida'
- 'Saukiidae belongs to Asaphida'
- 'Schmidtiellus belongs to Holmiidae'
- 'Segmentagnostus is a subjective synonym of Corrugatagnostus'
- 'Shumardiidae belongs to Ptychopariida'
- 'Sibiriaspis belongs to Abadiellidae'
- 'Sinodiscus belongs to Calodiscidae'
- 'Solenopleuridae belongs to Ptychopariida'
- 'Sphaeragnostidae belongs to Agnostida'
- 'Sphaeragnostus belongs to Sphaeragnostidae'
- 'Spinagnostidae belongs to Agnostida'
- 'Spinagnostiidae is a misspelling of Spinagnostidae'
- 'Spinagnostus is a subjective synonym of Hypagnostus'
- 'Styginidae belongs to Corynexochida'
- 'Tannudiscus belongs to Weymouthiidae'
- 'Telephinidae belongs to Proetida'
- 'Terechtaspis belongs to Chengkouaspidae'
- 'Tomagnostella belongs to Spinagnostidae'
- 'Tomagnostus belongs to Ptychagnostidae'
- 'Trilobagnostus belongs to Agnostidae'
- 'Trinodus belongs to Metagnostidae'
- 'Trinucleidae belongs to Asaphida'
- 'Tsinaniidae belongs to Corynexochida'
- 'Tsunyidiscidae belongs to Agnostida'
- 'Tsunyidiscus belongs to Tsunyidiscidae'
- 'Tungusella belongs to Redlichinidae'
- 'Utagnostus belongs to Clavagnostidae'
- 'Vinicella is a subjective synonym of Paradoxides'
- 'Wanneria belongs to Olenellidae'
- 'Weymouthia belongs to Weymouthiidae'
- 'Weymouthiidae belongs to Agnostida'
- 'Wutingaspis belongs to Redlichiidae'
- 'Xestagnostus belongs to Diplagnostidae'
- 'Xystridurinae belongs to Redlichiida'
- 'Yinitidae belongs to Redlichioidea'
- 'Yukoniidae belongs to Agnostida'
- 'Zacanthoididae belongs to Corynexochida'