Opinions from J. R. Macdonald 1963
- 'Allomys harkseni belongs to Allomys'
- 'Anchippus is a subjective synonym of Parahippus'
- 'Anchippus texanus is recombined as Parahippus texanus'
- 'Anchitherium brachylophus is a subjective synonym of Miohippus equiceps'
- 'Anchitherium equiceps is recombined as Miohippus equiceps'
- 'Ancodon leptodus is recombined as Arretotherium leptodus'
- 'Blastomeryx advena belongs to Blastomeryx'
- 'Canis lemur is recombined as Nothocyon lemur'
- 'Canis lemur is recombined as Nothocyon lemur' according to Hall and Martin 1930
- 'Canis lemur is recombined as Nothocyon lemur' according to Thorpe 1922
- 'Capacikala belongs to Castoridae'
- 'Capatanka belongs to Castoridae'
- 'Capatanka cankpeopi belongs to Capatanka'
- 'Cyclopidius emydinus is a subjective synonym of Cyclopidius simus'
- 'Cynodesmus cooki belongs to Cynodesmus'
- 'Cynodesmus thomsoni is recombined as Tomarctus thomsoni'
- 'Diceratherium gregorii belongs to Diceratherium'
- 'Domnina greeni belongs to Domnina'
- 'Domninoides evelynae belongs to Domninoides'
- 'Ekgmoiteptecela belongs to '
- 'Ekgmoiteptecela olsontau belongs to Ekgmoiteptecela'
- 'Ekgmowechashala belongs to Omomyidae'
- 'Ekgmowechashala philotau belongs to Ekgmowechashala'
- 'Entoptychus curtus is recombined as Gregorymys curtus'
- 'Entoptychus formosus is recombined as Gregorymys formosus'
- 'Euhapsis gaulodon is a subjective synonym of Capatanka brachyceps'
- 'Eumys blacki belongs to Eumys'
- 'Eumys woodi belongs to Eumys'
- 'Florentiamys agnewi belongs to Florentiamys'
- 'Galecynus latidens is recombined as Nothocyon latidens'
- 'Galecynus latidens is recombined as Nothocyon latidens' according to Hall and Martin 1930
- 'Galecynus latidens is recombined as Nothocyon latidens' according to Thorpe 1922
- 'Gentilicamelus wyomingensis is recombined as Oxydactylus wyomingensis'
- 'Gentilicamelus wyomingensis is a subjective synonym of Oxydactylus campestris' according to Stevens 1977
- 'Gentilicamelus wyomingensis belongs to Gentilicamelus' according to Loomis 1936
- 'Grangerimus dakotensis belongs to Grangerimus'
- 'Hitonkala belongs to Florentiamyidae'
- 'Hitonkala andersontau belongs to Hitonkala'
- 'Hoplophoneus belli belongs to Hoplophoneus'
- 'Hyaenocyon sectorius is recombined as Enhydrocyon sectorius'
- 'Hypertragulus ordinatus is recombined as Nanotragulus ordinatus'
- 'Hypolagus primitivus is recombined as Megalagus primitivus'
- 'Hypselochoerus is a subjective synonym of Desmatochoerus'
- 'Lepus macrocephalus is recombined as Archaeolagus macrocephalus'
- 'Lepus primigenius is recombined as Archaeolagus primigenius'
- 'Machaerodus brachyops is recombined as Nimravus brachyops'
- 'Machaerodus cerebralis belongs to Machaerodus'
- 'Machaerodus cerebralis belongs to Machaerodus' according to Cope 1880
- 'Merychyus delicatus is a subjective synonym of Merychyus minimus'
- 'Mesocyon geringensis is recombined as Sunkahetanka geringensis'
- 'Mesocyon hortulirosae is a subjective synonym of Mesocyon robustus'
- 'Mesocyon hortulirosae belongs to Mesocyon' according to Schlaikjer 1935
- 'Mesohippus acutidens is a subjective synonym of Miohippus equiceps'
- 'Neocynodesmus belongs to Canidae'
- 'Nothocyon gregorii is recombined as Hesperocyon gregorii'
- 'Nothocyon leptodus is recombined as Hesperocyon leptodus'
- 'Nothocyon leptodus belongs to Nothocyon' according to Schlaikjer 1935
- 'Nothocyon roii belongs to Nothocyon'
- 'Nothocyon vulpinus is recombined as Cynodesmus vulpinus'
- 'Ocajila belongs to Erinaceidae'
- 'Ocajila makpiyahe belongs to Ocajila'
- 'Oligobunis gemmarosae is recombined as Promartes gemmarosae'
- 'Oligobunis lepidus is recombined as Promartes lepidus'
- 'Pachycynodon delicatus is recombined as Neocynodesmus delicatus'
- 'Pachycynodon harlowi is recombined as Nothocyon harlowi'
- 'Palaeocastor milleri is recombined as Capacikala milleri'
- 'Palaeogale dorothiae belongs to Palaeogale'
- 'Parahippus pristinus belongs to Parahippus'
- 'Peratherium spindleri belongs to Peratherium'
- 'Pleurolicus clasoni belongs to Pleurolicus'
- 'Proheteromys bumpi belongs to Proheteromys'
- 'Proheteromys fedti belongs to Proheteromys'
- 'Proheteromys gremmelsi belongs to Proheteromys'
- 'Proheteromys ironcloudi belongs to Proheteromys'
- 'Promerycochoerus (Desmatochoerus) curvidens is recombined as Desmatochoerus curvidens'
- 'Promerycochoerus gregoryi is a subjective synonym of Desmatochoerus curvidens'
- 'Promerycochoerus pygmyus is a subjective synonym of Promerycochoerus minor'
- 'Prosciurus dawsonae belongs to Prosciurus'
- 'Steneofiber gradatus is recombined as Capacikala gradatus'
- 'Steneofiber sciuroides is recombined as Capacikala sciuroides'
- 'Sunkahetanka belongs to Canidae'
- 'Sunkahetanka pahinsintewakpa belongs to Sunkahetanka'
- 'Temnocyon venator belongs to Temnocyon'
- 'Temnocyon venator belongs to Temnocyon' according to Olsen 1958
- 'Temnocyon wallovianus belongs to Temnocyon'