Opinions from R. H. Tedford et al. 1987
- 'Araeocyon is a subjective synonym of Simocyon' according to Pilgrim 1931
- 'Araeocyon is a subjective synonym of Simocyon'
- 'Australocamelus is a subjective synonym of Oxydactylus'
- 'Beckia is a subjective synonym of Ischyrictis'
- 'Beckia grangerensis is recombined as Ischyrictis grangerensis'
- 'Borophagus littoralis is a subjective synonym of Epicyon saevus'
- 'Cosoryx belongs to Antilocapridae'
- 'Cosoryx (Paracosoryx) furlongi belongs to Cosoryx (Paracosoryx)'
- 'Cosoryx (Subcosoryx) cerroensis belongs to Cosoryx (Subcosoryx)'
- 'Cosoryx alticornis is recombined as Cosoryx (Paracosoryx) alticornis'
- 'Cosoryx dawesensis is recombined as Cosoryx (Paracosoryx) dawesensis'
- 'Cranioceras kinseyi is recombined as Rakomeryx kinseyi'
- 'Cynodesmus thooides is recombined as Mesocyon thooides'
- 'Daeodon is a subjective synonym of Dinohyus'
- 'Desmatippus belongs to Equidae'
- 'Desmatippus crenidens belongs to Desmatippus'
- 'Dinochoerus hollandi is recombined as Dinohyus hollandi'
- 'Dinochoerus hollandi is recombined as Dinohyus hollandi' according to Brunet 1975
- 'Dyseotylopus belongs to Camelidae'
- 'Dyseotylopus migrans belongs to Dyseotylopus'
- 'Hemicyon californicus is a subjective synonym of Hemicyon barstowensis'
- 'Hesperoscalops belongs to Talpidae'
- 'Hesperoscalops blancoensis belongs to Hesperoscalops'
- 'Hesperoscalops rexroadi belongs to Hesperoscalops'
- 'Hesperoscalops sewardensis belongs to Hesperoscalops'
- 'Hippotherium isonesum is recombined as Merychippus isonesus'
- 'Lambdoceras belongs to Protoceratidae'
- 'Lambdoceras hessei belongs to Lambdoceras'
- 'Mammut nevadanus is recombined as Pliomastodon nevadanus'
- 'Merycodus loxocerus is recombined as Paracosoryx loxocerus'
- 'Merycodus nevadensis is recombined as Paracosoryx nevadensis'
- 'Osteoborus crassapineatus is a subjective synonym of Borophagus dudleyi'
- 'Osteoborus diabloensis is a subjective synonym of Epicyon saevus'
- 'Oxydactylus brachyodontus is recombined as Tanymykter brachyodontus'
- 'Parablastomeryx belongs to Moschidae'
- 'Parablastomeryx is a subjective synonym of Blastomeryx' according to Carroll 1988
- 'Parablastomeryx falkenbachi is recombined as Pseudoblastomeryx falkenbachi'
- 'Parablastomeryx floridanus belongs to Parablastomeryx'
- 'Parablastomeryx marsa is recombined as Pseudoblastomeryx marsa'
- 'Parablastomeryx schultzi is recombined as Pseudoblastomeryx schultzi'
- 'Plioceros belongs to Antilocapridae'
- 'Plioceros blicki belongs to Plioceros'
- 'Plioceros dehlini belongs to Plioceros'
- 'Plioceros floblairi belongs to Plioceros'
- 'Pliocyon marshi is recombined as Simocyon marshi'
- 'Pliocyon marshi is recombined as Simocyon marshi' according to Pilgrim 1931
- 'Pliogulo is a subjective synonym of Borophagus'
- 'Pliogulo dudleyi is recombined as Borophagus dudleyi'
- 'Pliomastodon belongs to Mammutidae'
- 'Pliomastodon belongs to Mammutidae' according to Osborn 1926
- 'Pliomastodon adamsi belongs to Pliomastodon' according to Hibbard 1944
- 'Pliomastodon adamsi belongs to Pliomastodon'
- 'Prosynthetoceras trinitiensis is recombined as Lambdoceras trinitiensis'
- 'Protohippus avus is recombined as Desmatippus avus'
- 'Protohippus coalingensis is recombined as Dinohippus coalingensis'
- 'Pseudoblastomeryx belongs to Moschidae'
- 'Scalopus mcgrewi is recombined as Hesperoscalops mcgrewi'
- 'Scalopus ruficervus is recombined as Hesperoscalops ruficervus'
- 'Scalopus ruficervus belongs to Scalopus' according to Dalquest 1969
- 'Synthetoceras siouxensis is recombined as Lambdoceras siouxensis'
- 'Tanyorhinus is a subjective synonym of Dolichorhinus'
- 'Tanyorhinus belongs to ' according to Cook 1926
- 'Tanyorhinus blairi is recombined as Dolichorhinus blairi'
- 'Tanyorhinus blairi belongs to Tanyorhinus' according to Cook 1926
- 'Tanyorhinus bridgeri is recombined as Dolichorhinus bridgeri'
- 'Tanyorhinus bridgeri belongs to Tanyorhinus' according to Cook 1926
- 'Tanyorhinus harundivorax belongs to Tanyorhinus' according to Cook 1926
- 'Tanyorhinus harundivorax is recombined as Dolichorhinus harundivoras'
- 'Trilophodon paladentatus is a subjective synonym of Amebelodon hicksi'
- 'Ustatochoerus medius mohavensis is recombined as Mediochoerus mohavensis'
- 'Yumaceras is a subjective synonym of Cranioceras'