Opinions from J. G. M Thewissen et al. 2001
- 'Agriochoeridae belongs to Artiodactyla'
- 'Agriochoerus belongs to Agriochoeridae'
- 'Ambulocetidae belongs to Cetacea'
- 'Ambulocetus belongs to Ambulocetidae'
- 'Andrewsarchinae was reranked as the family Andrewsarchidae and belongs to Mesonychia'
- 'Andrewsarchus belongs to Andrewsarchidae'
- 'Ankalagon belongs to Mesonychidae'
- 'Anthracobunodon belongs to Haplobunodontidae'
- 'Anthracotheriidae belongs to Artiodactyla'
- 'Archaeotherium belongs to Entelodontidae'
- 'Arctocyon belongs to Arctocyonidae'
- 'Artiodactyla belongs to Cetartiodactyla'
- 'Bothriodon belongs to Anthracotheriidae'
- 'Camelidae belongs to Artiodactyla'
- 'Cebochoeridae belongs to Artiodactyla'
- 'Cebochoerus belongs to Cebochoeridae'
- 'Cebochoerus (Gervachoerus) was reranked as Gervachoerus and belongs to Cebochoeridae'
- 'Cetacea belongs to Cetartiodactyla'
- 'Cetartiodactyla belongs to Paraxonia'
- 'Diacodexis belongs to Dichobunidae'
- 'Diacodexis pakistanensis belongs to Diacodexis'
- 'Dichobunidae belongs to Artiodactyla'
- 'Dissacus belongs to Mesonychidae'
- 'Elomeryx belongs to Anthracotheriidae'
- 'Entelodontidae belongs to Artiodactyla'
- 'Eoconodon belongs to Andrewsarchidae'
- 'Hapalodectidae belongs to Mesonychia'
- 'Haplobunodon belongs to Haplobunodontidae'
- 'Haplobunodontidae belongs to Artiodactyla'
- 'Harpagolestes belongs to Mesonychidae'
- 'Hexaprotodon belongs to Hippopotamidae'
- 'Hippopotamidae belongs to Artiodactyla'
- 'Hippopotamus belongs to Hippopotamidae'
- 'Hyopsodus belongs to Hyopsodontidae'
- 'Ichthyolestes belongs to Pakicetidae'
- 'Indohyus belongs to Raoellidae'
- 'Khirtharia belongs to Raoellidae'
- 'Kunmunella belongs to Raoellidae'
- 'Meniscotherium belongs to Phenacodontidae'
- 'Mesonychia belongs to Paraxonia'
- 'Mesonychidae belongs to Mesonychia'
- 'Mesonyx belongs to Mesonychidae'
- 'Nalacetus belongs to Pakicetidae'
- 'Pachyaena belongs to Mesonychidae'
- 'Pakicetinae was reranked as the family Pakicetidae and belongs to Cetacea'
- 'Pakicetus belongs to Pakicetidae'
- 'Pantolestes secans is recombined as Diacodexis secans'
- 'Phenacodontidae belongs to Phenacodonta'
- 'Phenacodus belongs to Phenacodontidae'
- 'Poebrotherium belongs to Camelidae'
- 'Raoellidae belongs to Artiodactyla'
- 'Sinonyx belongs to Mesonychidae'
- 'Suidae belongs to Artiodactyla'
- 'Sus belongs to Suidae'
- 'Synoplotherium belongs to Mesonychidae'
- 'Tragulidae belongs to Artiodactyla'
- 'Tragulus belongs to Tragulidae'