Opinions from W. B. Scott 1940
- 'Aepinacodon is a subjective synonym of Bothriodon'
- 'Agriochoeridae belongs to Oreodontoidea'
- 'Agriochoerus belongs to Agriochoeridae'
- 'Agriochoerus antiquus belongs to Agriochoerus'
- 'Agriochoerus latifrons belongs to Agriochoerus'
- 'Agriochoerus major belongs to Agriochoerus'
- 'Agriochoerus maximus belongs to Agriochoerus'
- 'Agriochoerus minimus belongs to Agriochoerus'
- 'Agriomeryx is a subjective synonym of Agriochoerus'
- 'Agriomeryx migrans is a subjective synonym of Agriochoerus gaudryi'
- 'Ammodon potens is recombined as Pelonax potens'
- 'Ancodonta belongs to Artiodactyla'
- 'Ancodus rostratus is recombined as Bothriodon rostratus'
- 'Ancodus rostratus is recombined as Bothriodon rostratus' according to Scott 1937
- 'Ancodus rostratus is recombined as Bothriodon rostratus' according to Trouessart 1905
- 'Anthracotheriidae belongs to Ancodonta'
- 'Anthracotheriinae belongs to Anthracotheriidae'
- 'Anthracotherium karense is recombined as Heptacodon karensis'
- 'Anthracotherium karense belongs to Anthracotherium' according to Hay 1930
- 'Anthracotherium occidentale is recombined as Heptacodon occidentalis'
- 'Archaeotherium belongs to Entelodontidae'
- 'Archaeotherium marshi belongs to Archaeotherium'
- 'Archaeotherium mortoni belongs to Archaeotherium'
- 'Archaeotherium robustum is a subjective synonym of Archaeotherium mortoni'
- 'Archaeotherium scotti belongs to Archaeotherium'
- 'Archaeotherium wanlessi belongs to Archaeotherium'
- 'Arctodon vetustum is a subjective synonym of Archaeotherium mortoni'
- 'Arretotherium belongs to Bothriodontinae'
- 'Artionyx is a subjective synonym of Agriochoerus'
- 'Artionyx gaudryi is recombined as Agriochoerus gaudryi'
- 'Bathygenys belongs to Merycoidodontidae'
- 'Bathygenys alpha belongs to Bathygenys'
- 'Bothriodon belongs to Bothriodontinae'
- 'Bothriodontinae belongs to Anthracotheriidae'
- 'Calops belongs to Protoceratidae'
- 'Calops belongs to ' according to Marsh 1894
- 'Calops consors belongs to Calops'
- 'Calops cristatus belongs to Calops'
- 'Camelidae belongs to Cameloidea'
- 'Cameloidea belongs to Tylopoda'
- 'Coloreodon is a subjective synonym of Agriochoerus'
- 'Cotylops is a subjective synonym of Merycoidodon'
- 'Cotylops speciosa is a subjective synonym of Merycoidodon culbertsonii'
- 'Elomeryx belongs to Bothriodontinae'
- 'Elomeryx brachystylus is a subjective synonym of Elomeryx brachyrhynchus'
- 'Elomeryx brachystylus belongs to Elomeryx' according to Troxell 1921
- 'Elomeryx mitis is a subjective synonym of Elomeryx armatus'
- 'Elomeryx mitis belongs to Elomeryx' according to Hay 1930
- 'Elomeryx mitis is recombined as Anthracotherium mitis' according to Matthew 1899
- 'Elomeryx mitis belongs to Elomeryx' according to Marsh 1894
- 'Elotherium is a nomen dubium'
- 'Elotherium arctatum is a subjective synonym of Entelodon coarctatus'
- 'Elotherium arctatum belongs to Elotherium' according to Osborn 1891
- 'Elotherium bathrodon is a subjective synonym of Pelonax ramosus'
- 'Elotherium clavum is a subjective synonym of Archaeotherium mortoni'
- 'Elotherium coarctatum is recombined as Entelodon coarctatus'
- 'Elotherium crassum is recombined as Archaeotherium crassum'
- 'Elotherium ramosum is recombined as Pelonax ramosus'
- 'Entelodon belongs to Entelodontidae'
- 'Entelodon ingens is a nomen dubium'
- 'Entelodontidae belongs to Palaeodonta'
- 'Eotherium is a subjective synonym of Archaeotherium'
- 'Eotylopus belongs to Camelidae'
- 'Eotylopus reedi belongs to Eotylopus'
- 'Eporeodon belongs to Merycoidodontidae'
- 'Eporeodon cedrensis is a subjective synonym of Eporeodon major'
- 'Eporeodon socialis belongs to Eporeodon'
- 'Eucrotaphus is a nomen dubium'
- 'Eucrotaphus helenae is recombined as Eporeodon helenae'
- 'Eucrotaphus montanus is recombined as Eporeodon montanus'
- 'Heptacodon belongs to Bothriodontinae'
- 'Heptacodon belongs to Anthracotheriidae' according to Hay 1930
- 'Heptacodon armatus is recombined as Elomeryx armatus'
- 'Heptacodon armatus is recombined as Elomeryx armatus' according to Hay 1930
- 'Heptacodon curtus belongs to Heptacodon' according to Hay 1930
- 'Heptacodon curtus belongs to Heptacodon'
- 'Heptacodon gibbiceps belongs to Heptacodon'
- 'Heptacodon gibbiceps is recombined as Octacodon gibbiceps' according to Hay 1930
- 'Heptacodon quadratus belongs to Heptacodon'
- 'Heteromeryx belongs to Leptomerycinae'
- 'Heteromeryx dispar belongs to Heteromeryx'
- 'Hyopotamus americanus is recombined as Bothriodon americanus'
- 'Hyopotamus americanus is recombined as Ancodon americanus' according to Cook 1912
- 'Hyopotamus americanus is recombined as Ancodus americanus' according to Scott 1895
- 'Hyopotamus americanus belongs to Hyopotamus' according to O'Harra 1920
- 'Hyopotamus americanus belongs to Hyopotamus' according to Deperet 1912
- 'Hyopotamus americanus belongs to Hyopotamus' according to O'Harra 1910
- 'Hyopotamus americanus belongs to Hyopotamus' according to Osborn 1909
- 'Hyopotamus americanus belongs to Hyopotamus' according to Matthew 1901
- 'Hyopotamus americanus belongs to Hyopotamus' according to Matthew 1899
- 'Hyopotamus brachyrhynchus is recombined as Elomeryx brachyrhynchus' according to Hay 1930
- 'Hyopotamus brachyrhynchus is recombined as Elomeryx brachyrhynchus'
- 'Hypertragulidae belongs to Hypertraguloidea'
- 'Hypertragulinae belongs to Hypertragulidae'
- 'Hypertraguloidea belongs to Tylopoda'
- 'Hypertragulus belongs to Hypertragulinae'
- 'Hypertragulus tricostatus is a subjective synonym of Hypertragulus calcaratus'
- 'Hypisodontinae belongs to Hypertragulidae'
- 'Hypisodus belongs to Hypisodontinae'
- 'Hypisodus alacer belongs to Hypisodus'
- 'Hypisodus ringens is a subjective synonym of Hypisodus minimus'
- 'Laopithecus robustus is a subjective synonym of Leptochoerus spectabilis'
- 'Leptauchenia belongs to Merycoidodontidae'
- 'Leptauchenia calcarata is recombined as Hypertragulus calcaratus'
- 'Leptauchenia decora belongs to Leptauchenia'
- 'Leptauchenia major belongs to Leptauchenia'
- 'Leptauchenia minima is recombined as Hypisodus minimus'
- 'Leptauchenia nitida belongs to Leptauchenia'
- 'Leptochoeridae belongs to Palaeodonta'
- 'Leptochoerus belongs to Leptochoeridae'
- 'Leptochoerus gracilis belongs to Leptochoerus'
- 'Leptochoerus spectabilis belongs to Leptochoerus'
- 'Leptomerycidae was reranked as the subfamily Leptomerycinae and belongs to Hypertragulidae'
- 'Leptomeryx belongs to Leptomerycinae'
- 'Leptomeryx esulcatus belongs to Leptomeryx'
- 'Leptomeryx evansi belongs to Leptomeryx'
- 'Leptomeryx mammifer is recombined as Trigenicus mammifer'
- 'Leptomeryx semicinctus belongs to Leptomeryx'
- 'Leptomeryx speciosus belongs to Leptomeryx'
- 'Limnenetes belongs to Merycoidodontidae'
- 'Limnenetes anceps is recombined as Oreonetes anceps'
- 'Limnenetes platyceps belongs to Limnenetes'
- 'Megachoerus belongs to Entelodontidae'
- 'Megachoerus latidens belongs to Megachoerus'
- 'Megachoerus praecursor belongs to Megachoerus'
- 'Megachoerus zygomaticus belongs to Megachoerus'
- 'Menotherium is a subjective synonym of Leptochoerus'
- 'Menotherium lemurinum is a nomen dubium'
- 'Menotherium lemurinum is recombined as Leptochoerus lemurinus' according to Trouessart 1905
- 'Merycoidodon belongs to Merycoidodontidae'
- 'Merycoidodon culbertsonii belongs to Merycoidodon'
- 'Merycoidodon platycephalus belongs to Merycoidodon'
- 'Merycoidodontidae belongs to Oreodontoidea'
- 'Merycoidodontoidea is a subjective synonym of Oreodontoidea'
- 'Merycopater is a subjective synonym of Agriochoerus'
- 'Miolabis (Paratylopus) was reranked as Paratylopus and belongs to Camelidae'
- 'Miolabis (Paratylopus) primaevus is recombined as Paratylopus primaevus'
- 'Octacodon belongs to Bothriodontinae'
- 'Octacodon valens belongs to Octacodon'
- 'Oreodon is a subjective synonym of Merycoidodon'
- 'Oreodon affinis is recombined as Merycoidodon affinis'
- 'Oreodon bullatus is recombined as Eporeodon bullatus'
- 'Oreodon gracile is recombined as Merycoidodon gracilis'
- 'Oreodon hybridus is a subjective synonym of Eporeodon major'
- 'Oreodon macrorhinus is recombined as Merycoidodon macrorhinus'
- 'Oreodon major is recombined as Eporeodon major'
- 'Oreodon priscum is a subjective synonym of Merycoidodon culbertsonii'
- 'Oreodon robustum is a subjective synonym of Merycoidodon culbertsonii'
- 'Oreodontoidea belongs to Tylopoda'
- 'Oreonetes belongs to Merycoidodontidae'
- 'Palaeochoerus probus is recombined as Perchoerus probus'
- 'Palaeodonta belongs to Artiodactyla'
- 'Pelonax belongs to Entelodontidae'
- 'Perchoerus belongs to Tayassuidae'
- 'Perchoerus minor belongs to Perchoerus'
- 'Poebrotherium belongs to Camelidae'
- 'Poebrotherium andersoni is a subjective synonym of Poebrotherium labiatum'
- 'Poebrotherium eximium belongs to Poebrotherium'
- 'Poebrotherium labiatum belongs to Poebrotherium'
- 'Poebrotherium wilsoni belongs to Poebrotherium'
- 'Protoceras belongs to Protoceratidae'
- 'Protoceras celer belongs to Protoceras'
- 'Protoceras comptus belongs to Protoceras'
- 'Protoceras nasutus belongs to Protoceras'
- 'Protoceratidae belongs to Hypertraguloidea'
- 'Pseudolabis belongs to Camelidae'
- 'Pseudolabis (Paralabis) belongs to Pseudolabis'
- 'Pseudolabis (Paralabis) matthewi belongs to Pseudolabis (Paralabis)'
- 'Pseudolabis dakotensis belongs to Pseudolabis'
- 'Pseudoprotoceras belongs to Protoceratidae'
- 'Pseudoprotoceras longinaris belongs to Pseudoprotoceras'
- 'Rhinoceros americanus is a subjective synonym of Archaeotherium mortoni'
- 'Ruminantia was reranked as a unranked clade and belongs to Artiodactyla'
- 'Scaptohyus belongs to Entelodontidae'
- 'Scaptohyus altidens belongs to Scaptohyus'
- 'Stibarus belongs to Leptochoeridae'
- 'Stibarus loomisi belongs to Stibarus'
- 'Stibarus montanus belongs to Stibarus'
- 'Stibarus obtusilobus belongs to Stibarus'
- 'Suina belongs to Artiodactyla'
- 'Tayassuidae belongs to Suina'
- 'Thinohyus nanus is recombined as Perchoerus nanus'
- 'Trigenicus belongs to Merycoidodontidae'
- 'Trigenicus socialis belongs to Trigenicus'
- 'Trimerodus is a subjective synonym of Leptomeryx'
- 'Trimerodus belongs to ' according to Cope 1873
- 'Tylopoda was reranked as a suborder and belongs to Ruminantia'