Opinions from M. Kretzoi 1941
- 'Archaeosiren belongs to Eotherioidinae'
- 'Cheirotherium is replaced by Halysiren'
- 'Cornwallius belongs to Desmostylidae'
- 'Crassitherium belongs to Prototheriidae'
- 'Desmostylidae belongs to Desmostyliformes'
- 'Desmostyliformes belongs to Sirenia'
- 'Desmostylus belongs to Desmostylidae'
- 'Dioplotherium belongs to Prototheriidae'
- 'Dugongidae belongs to Trichechiformes'
- 'Dugonginae belongs to Dugongidae'
- 'Eosiren belongs to Eotherioidinae'
- 'Eotherioidinae belongs to Dugongidae'
- 'Eotheroides [misspelled as Eotherioides] belongs to Eotherioidinae'
- 'Felsinotherium is replaced by Halysiren'
- 'Halianassa belongs to Prototheriidae'
- 'Halitheriidae belongs to Trichechiformes'
- 'Halitherium belongs to Halitheriidae'
- 'Halitherium (Prototherium) was reranked as Prototherium and belongs to Prototheriidae'
- 'Hesperosiren belongs to Hydrodamalidae'
- 'Hydrodamalidae belongs to Trichechiformes'
- 'Hydrodamalis belongs to Hydrodamalidae'
- 'Manatherium belongs to Eotherioidinae'
- 'Masrisiren belongs to Metaxytheriinae'
- 'Metaxytheriinae belongs to Dugongidae'
- 'Metaxytherium belongs to Metaxytheriinae'
- 'Miosiren belongs to Miosireninae'
- 'Neodesmostylus belongs to Desmostylidae'
- 'Pachyacanthus belongs to Prototheriidae'
- 'Prohalicore belongs to Prototheriidae'
- 'Prorastomidae belongs to Trichechiformes'
- 'Prorastomus belongs to Prorastomidae'
- 'Protosiren belongs to Halitheriidae'
- 'Prototheriidae belongs to Trichechiformes'
- 'Ribodon belongs to Trichechidae'
- 'Rytiodontinae belongs to Dugongidae'
- 'Rytiodus belongs to Rytiodontinae'
- 'Sirenavus belongs to Prorastomidae'
- 'Thalattosiren belongs to Eotherioidinae'
- 'Trichechiformes belongs to Sirenia'
- 'Trichechus belongs to Trichechidae'
- 'Trichecidae is corrected as Trichechidae and belongs to Trichechiformes'