Opinions from R. H. Reinhart 1959
- 'Caribosiren belongs to Halianassinae'
- 'Cornwallius belongs to Desmostylidae'
- 'Cornwallius tabatai is recombined as Paleoparadoxia tabatai'
- 'Desmostylella is a subjective synonym of Desmostylus'
- 'Desmostylella typica is a subjective synonym of Desmostylus hesperus'
- 'Desmostylia belongs to Mammalia'
- 'Desmostylidae belongs to Desmostyliformes'
- 'Desmostyliformes belongs to Desmostylia'
- 'Desmostylus belongs to Desmostylidae'
- 'Desmostylus californicus is a subjective synonym of Desmostylus hesperus'
- 'Desmostylus cymatias is a subjective synonym of Desmostylus hesperus'
- 'Desmostylus hesperus belongs to Desmostylus'
- 'Desmostylus japonicus is a subjective synonym of Desmostylus hesperus'
- 'Desmostylus minor is a subjective synonym of Desmostylus hesperus'
- 'Desmostylus mirabilis is a subjective synonym of Desmostylus hesperus'
- 'Desmostylus sookensis is recombined as Cornwallius sookensis'
- 'Desmostylus watasei is a subjective synonym of Desmostylus hesperus'
- 'Dugongidae belongs to Sirenia'
- 'Dugonginae belongs to Dugongidae'
- 'Eotheroides belongs to Prorastominae'
- 'Halianassa belongs to Halianassinae'
- 'Halianassa vanderhoofi belongs to Halianassa'
- 'Halitheriidae was reranked as the family Halitheriinae and belongs to Dugongidae'
- 'Hydrodamalidae was reranked as the subfamily Hydrodamalinae and belongs to Dugongidae'
- 'Miosireninae belongs to Dugongidae'
- 'Paleoparadoxia belongs to Paleoparadoxidae'
- 'Paleoparadoxidae belongs to Desmostyliformes'
- 'Prorastomidae was reranked as the subfamily Prorastominae and belongs to Dugongidae'
- 'Prorastomus belongs to Prorastominae'
- 'Prorastomus sirenoides belongs to Prorastomus'
- 'Protosiren belongs to Protosireninae'
- 'Protosirenidae was reranked as the subfamily Protosireninae and belongs to Dugongidae'
- 'Rytiodinae belongs to Dugongidae'
- 'Trichecidae is corrected as Trichechidae and belongs to Sirenia'
- 'Vanderhoofius belongs to Desmostylidae'
- 'Vanderhoofius coalingensis belongs to Vanderhoofius'