Opinions from G. J. Heal 1973
- 'Anomotherium belongs to Halitheriinae'
- 'Archaeosiren is a subjective synonym of Eotheroides'
- 'Caribosiren belongs to Metaxytheriinae'
- 'Dugong belongs to Dugonginae'
- 'Dugongidae belongs to Dugongoidea'
- 'Dugongoidea belongs to Sirenia'
- 'Eosiren is a subjective synonym of Eotheroides'
- 'Eotherioidinae was reranked as the family Eotherioididae and belongs to Prorastomoidea'
- 'Eotheroides belongs to Eotheroididae'
- 'Eotheroididae belongs to Prorastomoidea'
- 'Felsinotherium belongs to Metaxytheriinae'
- 'Halitherium belongs to Halitheriinae'
- 'Halitherium (Prototherium) was reranked as Prototherium and belongs to Eotheroididae'
- 'Hippopotamus medius is recombined as Metaxytherium medium'
- 'Hydrodamalidae was reranked as the subfamily Hydrodamalinae and belongs to Dugongidae'
- 'Hydrodamalis belongs to Hydrodamalinae'
- 'Metaxytheriinae belongs to Dugongidae'
- 'Metaxytherium belongs to Metaxytheriinae'
- 'Miosiren belongs to Miosireninae'
- 'Miosireninae belongs to Dugongidae'
- 'Prorastomidae belongs to Prorastomoidea'
- 'Prorastomoidea belongs to Sirenia'
- 'Protosiren belongs to Protosirenidae'
- 'Protosirenidae belongs to Prorastomoidea'
- 'Ribodon belongs to Trichechidae'
- 'Ribodon limbatus belongs to Ribodon'
- 'Rytiodontinae belongs to Dugongidae'
- 'Rytiodus belongs to Rytiodontinae'
- 'Sirenavus belongs to Sirenia'
- 'Thalattosiren belongs to Halitheriinae'
- 'Trichechoidea belongs to Sirenia'
- 'Trichechus belongs to Trichechidae'
- 'Trichecidae is corrected as Trichechidae and belongs to Trichechoidea'