Opinions from O. P. Hay 1908
- 'Acherontemys belongs to Chelydridae'
- 'Acherontemys heckmani belongs to Acherontemys'
- 'Adocus belongs to Dermatemydidae'
- 'Adocus agilis belongs to Adocus' according to Cope 1868
- 'Adocus agilis belongs to Adocus'
- 'Adocus lacer belongs to Adocus'
- 'Adocus lineolatus belongs to Adocus'
- 'Adocus petrosus is recombined as Agomphus petrosus'
- 'Adocus punctatus belongs to Adocus'
- 'Adocus syntheticus belongs to Adocus'
- 'Alamosemys belongs to Dermatemydidae'
- 'Alamosemys substricta belongs to Alamosemys'
- 'Amblypeza belongs to Bothremydidae'
- 'Amblypeza antellius belongs to Amblypeza'
- 'Amblypeza entellus belongs to Amblypeza'
- 'Amphichelydia was reranked as a superfamily and belongs to Thecophora'
- 'Amphiemys oxysternum is recombined as Agomphus oxysternum'
- 'Amyda belongs to Trionychidae'
- 'Amyda crassa belongs to Amyda'
- 'Amyda egregia belongs to Amyda'
- 'Amyda exquisita belongs to Amyda'
- 'Amyda franciscae belongs to Amyda'
- 'Amyda mira belongs to Amyda'
- 'Anosteira belongs to Dermatemydidae'
- 'Anosteira ornata belongs to Anosteira'
- 'Anosteira radulina belongs to Anosteira'
- 'Anostira molopina is recombined as Plastomenus molopinus'
- 'Anostira oedemia is recombined as Plastomenus oedemius'
- 'Anostira trionychoides is recombined as Platypeltis trionychoides'
- 'Aspideretes belongs to Trionychidae'
- 'Aspideretes austerus belongs to Aspideretes'
- 'Aspideretes beecheri belongs to Aspideretes'
- 'Aspideretes ellipticus belongs to Aspideretes'
- 'Aspideretes fontanus belongs to Aspideretes'
- 'Aspideretes grangeri belongs to Aspideretes'
- 'Aspideretes nassau belongs to Aspideretes'
- 'Aspideretes puercensis belongs to Aspideretes'
- 'Aspideretes sagatus belongs to Aspideretes'
- 'Aspideretes splendidus belongs to Aspideretes'
- 'Aspidonectes tritor belongs to Aspidonectes' according to Hay 1904
- 'Aspidonectes tritor is recombined as Amyda tritor'
- 'Athecae belongs to Testudines'
- 'Atlantochelys mortoni belongs to Atlantochelys'
- 'Axestemys belongs to Trionychidae'
- 'Axestus byssinus is recombined as Axestemys byssina'
- 'Baena belongs to Baenidae'
- 'Baena affinis is a subjective synonym of Baena arenosa'
- 'Baena antiqua belongs to Baena'
- 'Baena arenosa belongs to Baena'
- 'Baena callosa belongs to Baena'
- 'Baena cephalica is recombined as Eubaena cephalica'
- 'Baena clara belongs to Baena'
- 'Baena emiliae belongs to Baena'
- 'Baena escavada belongs to Baena'
- 'Baena hatcheri belongs to Baena'
- 'Baena hebraica is recombined as Chisternon hebraicum'
- 'Baena marshi belongs to Baena'
- 'Baena ponderosa is a subjective synonym of Baptemys wyomingensis'
- 'Baena pulchra is recombined as Boremys pulchra'
- 'Baena sima belongs to Baena'
- 'Baena undata is recombined as Chisternon undatum'
- 'Baenidae belongs to Amphichelydia'
- 'Baptemys belongs to Dermatemydidae'
- 'Baptemys fluviatilis belongs to Baptemys'
- 'Baptemys tricarinata belongs to Baptemys'
- 'Basilemys belongs to Dermatemydidae'
- 'Basilemys sinuosa belongs to Basilemys'
- 'Boremys belongs to Baenidae'
- 'Bothremydidae belongs to Pleurodira'
- 'Bothremys belongs to Pleurodira'
- 'Bothremys cookii is corrected as Bothremys cooki and belongs to Bothremys'
- 'Catapleura belongs to Thalassemydidae'
- 'Catapleura ponderosa belongs to Catapleura'
- 'Charitemys belongs to Baenidae'
- 'Charitemys captans belongs to Charitemys'
- 'Chelone sopita is recombined as Osteopygis sopitus'
- 'Chelydra belongs to Chelydridae'
- 'Chelydra crassa is recombined as Hoplochelys crassa'
- 'Chelydridae belongs to Cryptodira'
- 'Chisternon belongs to Baenidae'
- 'Chrysemys inornata is recombined as Graptemys inornata'
- 'Chrysemys timida belongs to Chrysemys'
- 'Cistudo eurypygia is recombined as Terrapene eurypygia'
- 'Cistudo marnochii is recombined as Terrapene marnochi'
- 'Clemmys morrisiae belongs to Clemmys'
- 'Compsemys belongs to Dermatemydidae'
- 'Compsemys imbricarius is recombined as Basilemys imbricaria'
- 'Compsemys ogmius is a subjective synonym of Basilemys variolosa'
- 'Compsemys plicatulus is recombined as Glyptops plicatulus'
- 'Compsemys variolosus is recombined as Basilemys variolosa'
- 'Conchochelys belongs to Trionychidae'
- 'Conchochelys admirabilis belongs to Conchochelys' according to Hay 1905
- 'Conchochelys admirabilis belongs to Conchochelys'
- 'Cryptodira was reranked as a superfamily and belongs to Thecophora'
- 'Cynocercus belongs to Toxochelyidae'
- 'Deirochelys floridana belongs to Deirochelys'
- 'Dermatemydidae belongs to Cryptodira'
- 'Dermatemys costilata is recombined as Kallistira costilata'
- 'Desmatochelys lowii [misspelled as Desmatochelys lowi] belongs to Desmatochelys'
- 'Echmatemys aegle belongs to Echmatemys'
- 'Echmatemys arethusa belongs to Echmatemys'
- 'Echmatemys callopyge belongs to Echmatemys'
- 'Echmatemys cyane belongs to Echmatemys'
- 'Echmatemys naomi belongs to Echmatemys'
- 'Echmatemys ocyrrhoe belongs to Echmatemys'
- 'Echmatemys pusilla belongs to Echmatemys'
- 'Echmatemys uintensis belongs to Echmatemys'
- 'Emys beatus is recombined as Adocus beatus'
- 'Emys firmus is recombined as Agomphus firmus'
- 'Emys megaulax is recombined as Echmatemys megaulax'
- 'Emys obscurus is recombined as Compsemys obscura'
- 'Emys pravus is recombined as Adocus pravus'
- 'Emys septarius is recombined as Echmatemys septaria'
- 'Emys turgidus is recombined as Agomphus turgidus'
- 'Emys wyomingensis belongs to Emys'
- 'Erquelinnesia belongs to Thalassemydidae'
- 'Erquelinnesia molaria belongs to Erquelinnesia'
- 'Eubaena belongs to Baenidae'
- 'Eubaena latifrons belongs to Eubaena'
- 'Euclastes platyops is recombined as Rhetechelys platyops'
- 'Glyptops belongs to Pleurosternidae'
- 'Glyptops caelatus belongs to Glyptops'
- 'Glyptops depressus belongs to Glyptops'
- 'Glyptops ornatus is a subjective synonym of Glyptops plicatulus'
- 'Glyptops pervicax belongs to Glyptops'
- 'Hadrianus allabiatus is recombined as Achilemys allabiata'
- 'Hadrianus tumidus belongs to Hadrianus'
- 'Helopanoplia distincta belongs to Helopanoplia'
- 'Homorophus belongs to Dermatemydidae'
- 'Homorophus insuetus belongs to Homorophus' according to Cope 1870
- 'Homorophus insuetus belongs to Homorophus'
- 'Hoplochelys belongs to Dermatemydidae'
- 'Hoplochelys bicarinata belongs to Hoplochelys'
- 'Hoplochelys paludosa belongs to Hoplochelys'
- 'Hoplochelys saliens belongs to Hoplochelys'
- 'Kallistira belongs to Dermatemydidae'
- 'Lytoloma belongs to Thalassemydidae'
- 'Lytoloma angusta belongs to Lytoloma'
- 'Lytoloma jeanesii [misspelled as Lytoloma jeanesi] belongs to Lytoloma'
- 'Lytoloma wielandi belongs to Lytoloma'
- 'Macrochelys belongs to Chelydridae'
- 'Macrochelys floridana belongs to Macrochelys'
- 'Naiadochelys belongs to Bothremydidae'
- 'Naiadochelys ingravata belongs to Naiadochelys'
- 'Naomichelys belongs to Baenidae'
- 'Naomichelys speciosa belongs to Naomichelys'
- 'Neurankylus belongs to Baenidae'
- 'Neurankylus eximius belongs to Neurankylus'
- 'Notomorpha belongs to Dermatemydidae'
- 'Notomorpha garmanii is a subjective synonym of Notomorpha gravis'
- 'Notomorpha gravis belongs to Notomorpha'
- 'Notomorpha testudinea is recombined as Echmatemys testudinea'
- 'Osteopygis belongs to Thalassemydidae'
- 'Osteopygis chelydrinus belongs to Osteopygis'
- 'Osteopygis emarginatus belongs to Osteopygis'
- 'Osteopygis erosus belongs to Osteopygis'
- 'Osteopygis gibbi belongs to Osteopygis'
- 'Osteopygis platylomus belongs to Osteopygis'
- 'Osteopygis repandus is recombined as Catapleura repanda'
- 'Osteopygis robustus belongs to Osteopygis'
- 'Plastomenidae belongs to Trionychoidea'
- 'Plastomenus belongs to Plastomenidae'
- 'Plastomenus acupictus belongs to Plastomenus'
- 'Plastomenus catenatus belongs to Plastomenus'
- 'Plastomenus coalescens belongs to Plastomenus' according to Cope 1875
- 'Plastomenus coalescens is recombined as Aspideretes coalescens'
- 'Plastomenus communis belongs to Plastomenus'
- 'Plastomenus corrugatus belongs to Plastomenus'
- 'Plastomenus costatus belongs to Plastomenus'
- 'Plastomenus fractus belongs to Plastomenus'
- 'Plastomenus lachrymalis belongs to Plastomenus' according to Cope 1874
- 'Plastomenus lachrymalis belongs to Plastomenus'
- 'Plastomenus multifoveatus is a subjective synonym of Plastomenus thomasi'
- 'Plastomenus punctulatus belongs to Plastomenus'
- 'Plastomenus serialis is recombined as Platypeltis serialis'
- 'Plastomenus tantillus belongs to Plastomenus'
- 'Plastomenus visendus belongs to Plastomenus'
- 'Platecarpus tuberosus is recombined as Neptunochelys tuberosa'
- 'Platemys sulcatus is recombined as Taphrosphys sulcatus'
- 'Platypeltis belongs to Trionychidae'
- 'Platypeltis amnicola belongs to Platypeltis'
- 'Platypeltis antiqua belongs to Platypeltis'
- 'Platypeltis extensa belongs to Platypeltis'
- 'Platypeltis postera belongs to Platypeltis'
- 'Platypeltis trepida belongs to Platypeltis'
- 'Plesiochelys belviderensis belongs to Plesiochelys' according to Cragin 1902
- 'Plesiochelys belviderensis is recombined as Glyptops belviderensis'
- 'Pleurodira was reranked as a superfamily and belongs to Thecophora'
- 'Pleurosternidae belongs to Amphichelydia'
- 'Pleurosternum pectorale is recombined as Agomphus pectoralis'
- 'Polythorax belongs to Baenidae'
- 'Polythorax missuriensis belongs to Polythorax'
- 'Porthochelys browni belongs to Porthochelys'
- 'Porthochelys laticeps belongs to Porthochelys'
- 'Probaena belongs to Baenidae'
- 'Probaena sculpta belongs to Probaena' according to Hay 1903
- 'Prochonias is an objective synonym of Taphrosphys'
- 'Propleura borealis is recombined as Osteopygis borealis'
- 'Protostega advena belongs to Protostega'
- 'Protostega gigas belongs to Protostega'
- 'Protostega neptunia is an objective synonym of Atlantochelys mortoni'
- 'Protostega potens belongs to Protostega'
- 'Pseudemys caelata belongs to Pseudemys'
- 'Pseudemys extincta belongs to Pseudemys'
- 'Rhetechelys belongs to Thalassemydidae'
- 'Stylemys belongs to Testudinidae'
- 'Stylemys capax belongs to Stylemys'
- 'Stylemys conspecta belongs to Stylemys'
- 'Stylemys nebrascensis belongs to Stylemys'
- 'Taphrosphys belongs to Bothremydidae'
- 'Taphrosphys dares belongs to Taphrosphys'
- 'Taphrosphys leslianus belongs to Taphrosphys'
- 'Taphrosphys longinuchus belongs to Taphrosphys'
- 'Taphrosphys molops belongs to Taphrosphys'
- 'Taphrosphys nodosus belongs to Taphrosphys'
- 'Taphrosphys strenuus belongs to Taphrosphys'
- 'Temnotrionyx belongs to Trionychidae'
- 'Temnotrionyx manducans belongs to Temnotrionyx'
- 'Terrapene putnami is recombined as Testudo carolina putnami'
- 'Testudo campester belongs to Testudo'
- 'Testudo carolina longinsulae belongs to Testudo carolina'
- 'Testudo emiliae belongs to Testudo'
- 'Testudo farri belongs to Testudo'
- 'Testudo impensa belongs to Testudo'
- 'Testudo inusitata belongs to Testudo'
- 'Testudo pansa belongs to Testudo'
- 'Testudo serpentina is recombined as Chelydra serpentina'
- 'Testudo thomsoni belongs to Testudo'
- 'Testudo vaga belongs to Testudo'
- 'Thalassemydidae belongs to Cryptodira'
- 'Thecophora belongs to Testudines'
- 'Thescelus belongs to Baenidae'
- 'Thescelus insiliens belongs to Thescelus'
- 'Thescelus rapiens belongs to Thescelus'
- 'Terrapene anguillulatus is a subjective synonym of Terrapene eurypygia'
- 'Toxochelyidae belongs to Cryptodira'
- 'Toxochelys belongs to Toxochelyidae'
- 'Toxochelys brachyrhinus is corrected as Toxochelys brachyrhina and belongs to Toxochelys'
- 'Toxochelys elkader belongs to Toxochelys'
- 'Toxochelys latiremis belongs to Toxochelys'
- 'Toxochelys procax belongs to Toxochelys'
- 'Trachemys jarmani belongs to Trachemys'
- 'Trachemys sculpta belongs to Trachemys'
- 'Trachemys trulla belongs to Trachemys'
- 'Trionychidae belongs to Trionychoidea'
- 'Trionyx buiei is recombined as Amyda buiei'
- 'Trionyx cariosus is recombined as Amyda cariosa'
- 'Trionyx cellulosus is recombined as Amyda cellulosa'
- 'Trionyx concentricus is recombined as Amyda concentrica'
- 'Trionyx ferox belongs to Trionyx' according to Schneider 1783
- 'Trionyx ferox is recombined as Platypeltis ferox'
- 'Trionyx foveatus is recombined as Aspideretes foveatus'
- 'Trionyx guttatus is recombined as Aspideretes guttatus'
- 'Trionyx halophilus is recombined as Amyda halophila'
- 'Trionyx heteroglyptus is recombined as Platypeltis heteroglypta'
- 'Trionyx leptomitus is recombined as Plastomenus leptomitus'
- 'Trionyx leucopotamicus is recombined as Platypeltis leucopotamica'
- 'Trionyx lima is recombined as Amyda lima'
- 'Trionyx pennatus belongs to Trionyx' according to Cope 1869
- 'Trionyx pennatus is recombined as Amyda pennata'
- 'Trionyx priscus is recombined as Amyda prisca'
- 'Trionyx radulus is recombined as Amyda radula'
- 'Trionyx thomasii is recombined as Plastomenus thomasi'
- 'Trionyx uintaensis belongs to Trionyx' according to Leidy 1872
- 'Trionyx uintaensis is recombined as Amyda uintaensis'
- 'Trionyx vagans is recombined as Aspideretes vagans'
- 'Trionyx ventricosus is recombined as Amyda ventricosa'
- 'Trionyx virginianus belongs to Trionyx' according to Clark 1895
- 'Trionyx virginianus is recombined as Amyda virginiana'
- 'Xenochelys belongs to Dermatemydidae'
- 'Xenochelys formosa belongs to Xenochelys'
- 'Zygoramma belongs to Dermatemydidae'
- 'Zygoramma microglypha belongs to Zygoramma' according to Cope 1871
- 'Zygoramma microglypha belongs to Zygoramma'
- 'Zygoramma striatula belongs to Zygoramma'