Opinions from E. D. Cope 1875
- 'Alligator heterodon is recombined as Crocodilus heterodon'
- 'Ambloctonus belongs to Hyaenodontidae'
- 'Ambloctonus sinosus belongs to Ambloctonus'
- 'Antiacodon crassus belongs to Antiacodon'
- 'Antiacodon mentalis belongs to Antiacodon'
- 'Baena arenosa belongs to Baena'
- 'Bathmodon belongs to Pantodonta'
- 'Bathmodon cuspidatus belongs to Bathmodon'
- 'Bathmodon elephantopus belongs to Bathmodon'
- 'Bathmodon latidens belongs to Bathmodon'
- 'Bathmodon lomas belongs to Bathmodon'
- 'Bathmodon molestus belongs to Bathmodon'
- 'Bathmodon simus belongs to Bathmodon'
- 'Calamodon arcamaenus [misspelled as Calamodon arcamoenus] belongs to Calamodon'
- 'Calamodon novomehicanus belongs to Calamodon'
- 'Calamodon simplex belongs to Calamodon'
- 'Canidae belongs to Carnivora'
- 'Crocodilus chamensis belongs to Crocodilus' according to Cope 1874
- 'Crocodilus chamensis belongs to Crocodilus'
- 'Crocodilus elliottii belongs to Crocodilus' according to Leidy 1871
- 'Crocodilus elliottii belongs to Crocodilus'
- 'Crocodilus grypus belongs to Crocodilus'
- 'Crocodilus liodon belongs to Crocodilus'
- 'Crocodilus sphenops is recombined as Diplocynodus sphenops'
- 'Crocodilus wheelerii belongs to Crocodilus'
- 'Dermatemys costilata belongs to Dermatemys'
- 'Diacodon belongs to Insectivora'
- 'Diacodon alticuspis belongs to Diacodon'
- 'Diacodon celatus belongs to Diacodon'
- 'Dinocerata was reranked as a suborder and belongs to Amblypoda'
- 'Ectoganus gliriformis belongs to Ectoganus'
- 'Emys latilabiatus belongs to Emys'
- 'Emys stevensonianus belongs to Emys'
- 'Esthonyx bisulcatus belongs to Esthonyx'
- 'Esthonyx burmeisteri is corrected as Esthonyx burmeisterii and belongs to Esthonyx'
- 'Esthonyx miticulus is recombined as Hyopsodus miticulus'
- 'Felidae belongs to Carnivora'
- 'Helotherium procyoninum is recombined as Orohippus procyoninus'
- 'Hyaenidae belongs to Carnivora'
- 'Hyaenodontidae belongs to Carnivora'
- 'Hyopsodus paulus belongs to Hyopsodus'
- 'Hyrachyus singularis belongs to Hyrachyus'
- 'Limnocyon protenus is recombined as Didymictis protenus'
- 'Lophiodon (Coryphodon) was reranked as Coryphodon and belongs to Pantodonta'
- 'Orohippus pumilus is a subjective synonym of Orohippus procyoninus'
- 'Lophiotherium vasacciense is recombined as Orohippus vasacciensis'
- 'Loxolophodon belongs to Dinocerata'
- 'Meniscotherium chamense belongs to Meniscotherium'
- 'Metalophodon belongs to Pantodonta'
- 'Mustelidae belongs to Carnivora'
- 'Opisthotomus belongs to Quadrumana'
- 'Opisthotomus astutus belongs to Opisthotomus'
- 'Opisthotomus flagrans belongs to Opisthotomus'
- 'Orohippus agilis belongs to Orohippus'
- 'Orohippus angustidens belongs to Orohippus'
- 'Orohippus cuspidatus belongs to Orohippus'
- 'Orohippus major belongs to Orohippus'
- 'Orohippus tapirinus belongs to Orohippus'
- 'Orotherium uintanum [misspelled as Orotherium vintanum] belongs to Orotherium'
- 'Oxyaena forcipata belongs to Oxyaena'
- 'Oxyaena lupina belongs to Oxyaena'
- 'Oxyaena morsitans belongs to Oxyaena'
- 'Pachyaena ossifraga belongs to Pachyaena'
- 'Pantodonta was reranked as a suborder and belongs to Amblypoda'
- 'Pantolestes chacensis belongs to Pantolestes'
- 'Pantolestes longieundus is corrected as Pantolestes longicaudus and belongs to Pantolestes'
- 'Paramys delicatior belongs to Paramys'
- 'Paramys delicatissimus belongs to Paramys'
- 'Pelycodus belongs to Quadrumana'
- 'Pelycodus angulatus belongs to Pelycodus'
- 'Pelycodus frugivorus belongs to Pelycodus'
- 'Phenacodus omnivorus belongs to Phenacodus'
- 'Phenacodus primaeous is corrected as Phenacodus primaevus and belongs to Phenacodus'
- 'Phenacodus sulcatus belongs to Phenacodus'
- 'Plastomenus catenatus belongs to Plastomenus'
- 'Plastomenus communis belongs to Plastomenus'
- 'Plastomenus corrugatus belongs to Plastomenus'
- 'Plastomenus fractus belongs to Plastomenus'
- 'Plastomenus lachrymalis belongs to Plastomenus'
- 'Prototomus insidiosus is recombined as Apheliscus insidiosus'
- 'Prototomus jarrovii is recombined as Pelycodus jarrovii'
- 'Prototomus multicuspis belongs to Prototomus'
- 'Prototomus secundarius belongs to Prototomus'
- 'Prototomus strenuus belongs to Prototomus'
- 'Prototomus viverrinus belongs to Prototomus'
- 'Testudo corsoni is recombined as Hadrianus corsonii'
- 'Trionyx cariosus belongs to Trionyx'
- 'Trionyx leptomitus belongs to Trionyx'
- 'Trionyx radulus belongs to Trionyx'
- 'Trionyx thomasii is recombined as Plastomenus thomasii'
- 'Trionyx uintaensis belongs to Trionyx'
- 'Uintatherium belongs to Dinocerata'
- 'Viverridae belongs to Carnivora'