Opinions from D. R. Prothero and R. M. Schoch 1989
- 'Aceratheriinae belongs to Rhinocerotidae'
- 'Aceratherium belongs to Aceratheriinae'
- 'Acerorhinus belongs to Aceratheriinae'
- 'Acrotitan belongs to Brontotheridae'
- 'Alicornops belongs to Aceratheriinae'
- 'Allacerops is a subjective synonym of Eggysodon'
- 'Alloceropinae belongs to Hyracodontidae'
- 'Allops is a subjective synonym of Menops'
- 'Altungulata belongs to Ungulata'
- 'Amphicaenopus belongs to Rhinocerotidae'
- 'Anchilophus belongs to Pachynolophidae'
- 'Anchitheridae was reranked as the subfamily Anchitheriinae and belongs to Equidae'
- 'Anchitherium belongs to Anchitheriinae'
- 'Anchitherium (Hypohippus) was reranked as Hypohippus and belongs to Anchitheriinae'
- 'Anchitherium (Parahippus) was reranked as Parahippus and belongs to Equinae'
- 'Ancylopoda was reranked as a unranked clade and belongs to Rhinotapiromorpha'
- 'Ancylotherium belongs to Schizotheriinae'
- 'Aphelops belongs to Aceratheriinae'
- 'Aprotodon belongs to Teleoceratini'
- 'Archaeohippus belongs to Equinae'
- 'Ardynia belongs to Hyracodontinae'
- 'Asinus is a subjective synonym of Equus'
- 'Atalonodon belongs to Lophiodontidae'
- 'Aulaxolophus belongs to Rhinotapiromorpha'
- 'Borissiakia belongs to Schizotheriinae'
- 'Brachydiastematherium belongs to Brontotheridae'
- 'Brachydiceratherium belongs to Teleoceratini'
- 'Brachypodella belongs to Teleoceratini'
- 'Brachypotherium belongs to Teleoceratini'
- 'Brontops belongs to Telmatheriinae'
- 'Brontotheridae is corrected as Brontotheriidae and belongs to Brontotherioidea'
- 'Brontotherioidea belongs to Titanotheriomorpha'
- 'Brontotherium is a subjective synonym of Megacerops'
- 'Bunohyrax belongs to Saghatheriinae'
- 'Caenopus is a subjective synonym of Subhyracodon'
- 'Cantabrotherium belongs to Palaeotheriidae'
- 'Ceratorhinus is a subjective synonym of Dicerorhinus'
- 'Ceratotherium belongs to Dicerotina'
- 'Chalicotheriidae belongs to Chalicotherioidea'
- 'Chalicotheriinae belongs to Chalicotheriidae'
- 'Chalicotherioidea belongs to Ancylopoda'
- 'Chalicotherium belongs to Chalicotheriinae'
- 'Chemositia is a subjective synonym of Ancylotherium'
- 'Chilotheridium belongs to Aceratheriinae'
- 'Chilotherium belongs to Aceratheriinae'
- 'Coelodonta belongs to Dicerorhinina'
- 'Colonoceras is a subjective synonym of Hyrachyus'
- 'Cormohipparion belongs to Hippotheriini'
- 'Cymbalophus belongs to Equoidea'
- 'Dendrohyrax belongs to Procaviidae'
- 'Dendrohyrax (Heterohyrax) was reranked as Heterohyrax and belongs to Procaviidae'
- 'Desmatotitan belongs to Brontotheridae'
- 'Diaceratherium belongs to Teleoceratini'
- 'Dianotitan belongs to Brontotheridae'
- 'Diceratheriinae belongs to Rhinocerotidae'
- 'Diceratherium belongs to Diceratheriinae'
- 'Dicerorhinini was reranked as the subtribe Dicerorhinina and belongs to Rhinocerotini'
- 'Dicerorhinus belongs to Dicerorhinina'
- 'Diceros belongs to Dicerotina'
- 'Dicerotini was reranked as the subtribe Dicerotina and belongs to Rhinocerotini'
- 'Didermocerus is a subjective synonym of Dicerorhinus'
- 'Dilophodon belongs to Tapiroidea'
- 'Dinohippus belongs to Equini'
- 'Diplacodon belongs to Brontotheridae'
- 'Diploclonus is a subjective synonym of Brontops'
- 'Dolichohippus is a subjective synonym of Equus'
- 'Dolichorhinae is corrected as Dolichorhininae and belongs to Brontotheridae'
- 'Dolichorhinoides belongs to Brontotheridae'
- 'Dolichorhinus belongs to Dolichorhininae'
- 'Dromoceratherium belongs to Aceratheriinae'
- 'Duchesneodus belongs to Telmatheriinae'
- 'Eggysodon belongs to Alloceropinae'
- 'Elasmotheriina was reranked as a subtribe and belongs to Rhinocerotini'
- 'Elasmotherium belongs to Elasmotheriina'
- 'Embolotherium belongs to Brontotheridae'
- 'Embrithopoda belongs to Altungulata'
- 'Eometarhinus is a subjective synonym of Palaeosyops'
- 'Eomoropus belongs to Chalicotheriidae'
- 'Eotitanops belongs to Brontotheridae'
- 'Eotitanotherium belongs to Telmatheriinae'
- 'Eotrigonias is a subjective synonym of Triplopus'
- 'Epiaceratherium belongs to Rhinocerotidae'
- 'Epihippus belongs to Equidae'
- 'Epimanteoceras belongs to Brontotheridae'
- 'Epitriplopus belongs to Hyracodontinae'
- 'Equidae belongs to Equoidea'
- 'Equinae belongs to Equidae'
- 'Equini belongs to Equinae'
- 'Equoidea belongs to Hippomorpha'
- 'Equus belongs to Equini'
- 'Equus (Protohippus) was reranked as Protohippus and belongs to Equini'
- 'Ergilia is a subjective synonym of Ardynia'
- 'Eutheria was reranked as a infraclass and belongs to Theria'
- 'Floridaceras belongs to Aceratheriinae'
- 'Gaindatherium belongs to Rhinocerotina'
- 'Gansuodon is a subjective synonym of Ancylotherium'
- 'Geniohyidae was reranked as the subfamily Geniohyinae and belongs to Pliohyracidae'
- 'Geniohyus belongs to Geniohyinae'
- 'Gigantohyrax belongs to Procaviidae'
- 'Gnathotitan belongs to Brontotheridae'
- 'Gobihippus belongs to Equidae'
- 'Grangeria belongs to Chalicotheriidae'
- 'Haplohippus belongs to Equidae'
- 'Hemionus is a subjective synonym of Equus'
- 'Heptacodon belongs to Embrithopoda'
- 'Heteraletes is a subjective synonym of Dilophodon'
- 'Hipparion belongs to Hippotheriini'
- 'Hipparion (Nannippus) was reranked as Nannippus and belongs to Hippotheriini'
- 'Hippidion belongs to Equini'
- 'Hippomorpha was reranked as a infraorder and belongs to Mesaxonia'
- 'Hippotheriina is corrected as Hippotheriini and belongs to Equinae'
- 'Hippotherium belongs to Hippotheriini'
- 'Hippotigris is a subjective synonym of Equus'
- 'Hispanotherium belongs to Elasmotheriina'
- 'Hoangkotherium is a subjective synonym of Ancylotherium'
- 'Homogalax belongs to Isectolophidae'
- 'Hoploaceratherium belongs to Aceratheriinae'
- 'Hyotitan belongs to Brontotheridae'
- 'Hyracodon belongs to Hyracodontinae'
- 'Hyracoidea was reranked as a suborder and belongs to Perissodactyla'
- 'Hyracotherium belongs to Equoidea'
- 'Ilianodon belongs to Alloceropinae'
- 'Indolophidae belongs to Hippomorpha'
- 'Indolophus belongs to Indolophidae'
- 'Iranotherium belongs to Elasmotheriina'
- 'Isectolophidae belongs to Isectolophomorpha'
- 'Isectolophomorpha belongs to Moropomorpha'
- 'Isectolophus belongs to Isectolophidae'
- 'Kalakotia belongs to Rhinotapiromorpha'
- 'Kalobatippus belongs to Equinae'
- 'Kenyatherium belongs to Elasmotheriina'
- 'Kolpohippus is a subjective synonym of Equus'
- 'Kraterohippus is a subjective synonym of Equus'
- 'Kvabebihyrax belongs to Pliohyracinae'
- 'Lambdotheriidae belongs to Brontotherioidea'
- 'Lambdotherium belongs to Lambdotheriidae'
- 'Lartetotherium belongs to Dicerorhinina'
- 'Leptolophus belongs to Palaeotheriidae'
- 'Leurocephalus is a subjective synonym of Telmatherium'
- 'Limnohyops is a subjective synonym of Palaeosyops'
- 'Limnohyus is a subjective synonym of Palaeosyops'
- 'Litolophus belongs to Chalicotheriidae'
- 'Lophiaspis belongs to Lophiodontidae'
- 'Lophiodochoerus belongs to Lophiodontidae'
- 'Lophiodon belongs to Lophiodontoidea'
- 'Lophiodontidae belongs to Lophiodontoidea'
- 'Lophiodontoidea belongs to Ancylopoda'
- 'Lophiotherium belongs to Palaeotheriidae'
- 'Lunania belongs to Embrithopoda'
- 'Macrotherium belongs to Schizotheriinae'
- 'Manteoceras is a subjective synonym of Telmatherium'
- 'Megacerops belongs to Telmatheriinae'
- 'Megahippus belongs to Anchitheriinae'
- 'Megalohyrax belongs to Saghatheriinae'
- 'Meninatherium is a subjective synonym of Prohyracodon'
- 'Menoceras belongs to Menoceratinae'
- 'Menoceratinae belongs to Rhinocerotidae'
- 'Menops belongs to Telmatheriinae'
- 'Meroehyrax belongs to Saghatheriinae'
- 'Merychippus belongs to Equinae'
- 'Mesaceratherium belongs to Aceratheriinae'
- 'Mesatirhinus belongs to Dolichorhininae'
- 'Mesaxonia was reranked as a suborder and belongs to Perissodactyla'
- 'Meschotherium belongs to Rhinocerotoidea'
- 'Mesohippus belongs to Equidae'
- 'Metahyrachyus is a subjective synonym of Hyrachyus'
- 'Metaschizotherium is a subjective synonym of Ancylotherium'
- 'Metatelmatherium belongs to Telmatheriinae'
- 'Metatitan belongs to Brontotheridae'
- 'Microhyrax belongs to Saghatheriinae'
- 'Microtitan belongs to Brontotheridae'
- 'Miohippus belongs to Equidae'
- 'Moropomorpha was reranked as a infraorder and belongs to Mesaxonia'
- 'Moropus belongs to Schizotheriinae'
- 'Moschoedestes is a subjective synonym of Menoceras'
- 'Neohipparion belongs to Hippotheriini'
- 'Neohippus is a subjective synonym of Equus'
- 'Nestoritherium belongs to Chalicotheriinae'
- 'Ninxiatherium belongs to Rhinocerotoidea'
- 'Notiotitanops belongs to Telmatheriinae'
- 'Notohipparion is a subjective synonym of Hipparion'
- 'Olsenia belongs to Chalicotheriidae'
- 'Onager is a subjective synonym of Equus'
- 'Onohippidium belongs to Equini'
- 'Orohippus belongs to Equidae'
- 'Pachyhyrax belongs to Saghatheriinae'
- 'Pachynolophidae belongs to Pachynolophoidea'
- 'Pachynolophoidea belongs to Hippomorpha'
- 'Pachynolophus belongs to Pachynolophidae'
- 'Pachytitan belongs to Brontotheridae'
- 'Palaeosyops belongs to Brontotheridae'
- 'Palaeotheriidae belongs to Equoidea'
- 'Palaeotherium belongs to Palaeotheriidae'
- 'Menodus is a nomen dubium'
- 'Paleomoropus belongs to Lophiodontidae'
- 'Parabrontops belongs to Brontotheridae'
- 'Paradiceros belongs to Dicerotina'
- 'Parahipparion is a subjective synonym of Hippidion'
- 'Paralophiodon belongs to Lophiodontidae'
- 'Paraplagiolophus belongs to Palaeotheriidae'
- 'Parapliohyrax belongs to Pliohyracinae'
- 'Penetrigonias belongs to Rhinocerotidae'
- 'Peraceras belongs to Aceratheriinae'
- 'Perissodactyla was reranked as a order and belongs to Altungulata'
- 'Phyllotillon belongs to Schizotheriinae'
- 'Plagiolophus belongs to Palaeotheriidae'
- 'Plesiaceratherium belongs to Aceratheriinae'
- 'Plesippus is a subjective synonym of Equus'
- 'Pleuroceros belongs to Menoceratinae'
- 'Pliohippus belongs to Equini'
- 'Pliohippus (Astrohippus) was reranked as Astrohippus and belongs to Equini'
- 'Pliohyracidae belongs to Hyracoidea'
- 'Pliohyracinae belongs to Pliohyracidae'
- 'Pliohyrax belongs to Pliohyracinae'
- 'Pliolophus belongs to Equoidea'
- 'Postschizotherium belongs to Pliohyracinae'
- 'Proaceratherium belongs to Aceratheriinae'
- 'Proboscidipparion is a subjective synonym of Hipparion'
- 'Procavia belongs to Procaviidae'
- 'Procaviidae belongs to Hyracoidea'
- 'Prohyracodon belongs to Alloceropinae'
- 'Prohyrax belongs to Pliohyracinae'
- 'Propachynolophus belongs to Palaeotheriidae'
- 'Propalaeotherium belongs to Palaeotheriidae'
- 'Prosantorhinus belongs to Teleoceratini'
- 'Protembolotherium belongs to Brontotheridae'
- 'Protitan belongs to Brontotheridae'
- 'Protitanops belongs to Brontotheridae'
- 'Protitanotherium belongs to Telmatheriinae'
- 'Protoaceratherium is corrected as Protaceratherium and belongs to Menoceratinae'
- 'Protohippus (Calippus) was reranked as Calippus and belongs to Equini'
- 'Protorohippus belongs to Equidae'
- 'Pseudhipparion belongs to Hippotheriini'
- 'Pseudopalaeotherium belongs to Palaeotheriidae'
- 'Punjabitherium belongs to Rhinocerotoidea'
- 'Radinskya belongs to Embrithopoda'
- 'Rhadinorhinus belongs to Dolichorhininae'
- 'Rhinocerina was reranked as the subtribe Rhinocerotina and belongs to Rhinocerotini'
- 'Rhinoceros belongs to Rhinocerotina'
- 'Rhinocerotidae belongs to Rhinocerotida'
- 'Rhinocerotinae belongs to Rhinocerotidae'
- 'Rhinocerotini belongs to Rhinocerotinae'
- 'Rhinotapiromorpha belongs to Moropomorpha'
- 'Rhinotitan belongs to Brontotheridae'
- 'Ronzotherium belongs to Rhinocerotidae'
- 'Saghatheriidae was reranked as the subfamily Saghatheriinae and belongs to Pliohyracidae'
- 'Saghatherium belongs to Saghatheriinae'
- 'Sastrilophus belongs to Isectolophidae'
- 'Schizolophodon is a subjective synonym of Isectolophus'
- 'Schizotheriinae belongs to Chalicotheriidae'
- 'Schizotheriodes is corrected as Schizotheroides and belongs to Lophiodontidae'
- 'Seggeurius belongs to Geniohyinae'
- 'Selenohyrax belongs to Saghatheriinae'
- 'Sinohippus belongs to Anchitheriinae'
- 'Sinotherium belongs to Elasmotheriina'
- 'Sivatitanops belongs to Brontotheridae'
- 'Soqdohyrax belongs to Pliohyracinae'
- 'Sphenocoelus belongs to Brontotheridae'
- 'Stephanorhinus belongs to Dicerorhinina'
- 'Sterrohippus is a subjective synonym of Equus'
- 'Sthenodectes belongs to Telmatheriinae'
- 'Stylohipparion belongs to Hippotheriini'
- 'Subchilotherium belongs to Aceratheriinae'
- 'Subhyracodon belongs to Diceratheriinae'
- 'Symborodon belongs to Brontotheridae'
- 'Symphysorrhachis belongs to Rhinocerotoidea'
- 'Systemodon belongs to Equoidea'
- 'Tapiridea belongs to Ceratomorpha'
- 'Tapiroidea belongs to Tapiridea'
- 'Teilhardina is a subjective synonym of Caenolophus'
- 'Teleoceras belongs to Teleoceratini'
- 'Teleoceratini belongs to Rhinocerotinae'
- 'Teleodus belongs to Telmatheriinae'
- 'Teletaceras belongs to Rhinocerotidae'
- 'Telmatheriinae belongs to Brontotheridae'
- 'Telmatherium belongs to Telmatheriinae'
- 'Tethytheria was reranked as a order and belongs to Altungulata'
- 'Theria belongs to Mammalia'
- 'Thyrohyrax belongs to Saghatheriinae'
- 'Tichorhinus is a subjective synonym of Coelodonta'
- 'Titanodectes belongs to Brontotheridae'
- 'Titanohyrax belongs to Saghatheriinae'
- 'Titanops is a subjective synonym of Megacerops'
- 'Titanotheriomorpha was reranked as a infraorder and belongs to Perissodactyla'
- 'Titanotherium belongs to Brontotheridae'
- 'Toxotherium belongs to Lophiodontidae'
- 'Trigonias belongs to Rhinocerotidae'
- 'Triplopides belongs to Hyracodontinae'
- 'Tylocephalonyx belongs to Schizotheriinae'
- 'Ungulata was reranked as a superorder and belongs to Eutheria'
- 'Xenicohippus belongs to Lambdotheriidae'