Opinions from M. A. Cozzuol 1996
- 'Aglaocetus belongs to Cetotheriidae'
- 'Argyrocetus belongs to Eurhinodelphidae'
- 'Argyrocetus patagonicus belongs to Argyrocetus'
- 'Atocetus belongs to Pithanodelphinae'
- 'Atocetus iquensis belongs to Atocetus'
- 'Australithax belongs to Phocoenidae'
- 'Australithax intermedia belongs to Australithax'
- 'Balaenoptera siberi belongs to Balaenoptera'
- 'Balanadae is corrected as Balaenidae and belongs to Mysticeti'
- 'Belonodelphis belongs to Kentriodontidae'
- 'Belonodelphis peruanus belongs to Belonodelphis'
- 'Brachydelphis belongs to Brachydelphinae'
- 'Brachydelphis mazeasi belongs to Brachydelphis'
- 'Cetotheriinae was reranked as the family Cetotheriidae and belongs to Mysticeti'
- 'Cetotherium moreni is recombined as Aglaocetus moreni'
- 'Crenaticeti belongs to Mysticeti'
- 'Delphinus geoffrensis is recombined as Inia geoffrensis'
- 'Diaphorocetus belongs to Physeteridae'
- 'Idiorophus belongs to Physeteridae'
- 'Incacetus belongs to Kentriodontidae'
- 'Incacetus broggii belongs to Incacetus'
- 'Inia belongs to Iniinae'
- 'Inia boliviensis belongs to Inia'
- 'Iniinae belongs to Iniidae'
- 'Ischyrorhynchinae belongs to Iniidae'
- 'Ischyrorhynchus belongs to Ischyrorhynchinae'
- 'Ischyrorhynchus vanbenedeni belongs to Ischyrorhynchus'
- 'Llanocetidae belongs to Crenaticeti'
- 'Llanocetus belongs to Llanocetidae'
- 'Llanocetus denticrenatus belongs to Llanocetus'
- 'Lomacetus belongs to Phocoenidae'
- 'Lomacetus ginsburgi belongs to Lomacetus'
- 'Mesocetus poucheti is recombined as Diaphorocetus poucheti'
- 'Morenocetus belongs to Balaenidae'
- 'Morenocetus parvus belongs to Morenocetus'
- 'Notiocetus belongs to Balaenopteridae'
- 'Notiocetus romerianus belongs to Notiocetus'
- 'Periptychus argentinus is recombined as Properiptychus argentinus'
- 'Phoberodon belongs to Squalodontidae'
- 'Phoberodon arctirostris belongs to Phoberodon'
- 'Physodon patagonicus is recombined as Idiorophus patagonicus'
- 'Piscorhynchus belongs to Pontoporiidae'
- 'Piscorhynchus aenigmaticus belongs to Piscorhynchus'
- 'Plesiocetus belongs to Cetotheriidae'
- 'Plesiocetus dyticus belongs to Plesiocetus'
- 'Pontistes belongs to Pontoporiidae'
- 'Potamosiren belongs to Trichechidae'
- 'Potamosiren magdalenensis belongs to Potamosiren'
- 'Preaulophyseter belongs to Physeteridae'
- 'Properiptychus belongs to Monachinae'
- 'Prosqualodon belongs to Prosqualodontidae'
- 'Ribodon belongs to Trichechidae'
- 'Ribodon limbatus belongs to Ribodon'
- 'Saurocetes belongs to Ischyrorhynchinae'
- 'Saurocetes argentinus belongs to Saurocetes'
- 'Saurodelphis is a subjective synonym of Saurocetes'
- 'Saurodelphis gigas is recombined as Saurocetes gigas'
- 'Scaphokogia belongs to Kogiinae'
- 'Scaphokogia cochlearis belongs to Scaphokogia'
- 'Sirenotherium pirabense is a nomen dubium'
- 'Uranocetus belongs to Pontoporiidae'