Opinions from F. Ameghino 1901
- 'Argyrocetus belongs to Argyrocetidae'
- 'Argyrocetus patagonicus belongs to Argyrocetus'
- 'Argyrodelphis benedeni is recombined as Diochotichus benedeni'
- 'Carcharidae belongs to Selachii'
- 'Carcharodon belongs to Lamnidae'
- 'Carcharoides belongs to Lamnidae'
- 'Carcharoides totuserratus belongs to Carcharoides'
- 'Diaphorocetus belongs to Physeteridae'
- 'Diochotichus belongs to Platanistidae'
- 'Eucetites belongs to Balaenidae'
- 'Galeocerdo belongs to Carcharidae'
- 'Galeocerdo mixtus belongs to Galeocerdo'
- 'Globicephala [misspelled as Globicephalus] belongs to Delphinidae'
- 'Globicephalus eocaenus belongs to Globicephalus'
- 'Homunculites belongs to Homunculidae'
- 'Lamna belongs to Lamnidae'
- 'Mesocetus poucheti is recombined as Diaphorocetus poucheti'
- 'Myliobatidae belongs to Selachii'
- 'Myliobatis belongs to Myliobatidae'
- 'Notidanus belongs to Notidanidae'
- 'Notidanus ultra belongs to Notidanus'
- 'Odontaspis belongs to Lamnidae'
- 'Oxyprinichthys belongs to Lamnidae'
- 'Oxyprinichthys aprioniferus belongs to Oxyprinichthys'
- 'Oxyprinichthys prioniferus belongs to Oxyprinichthys'
- 'Oxyrhina belongs to Lamnidae'
- 'Oxyrhina uncidens belongs to Oxyrhina'
- 'Pachyrukhos [misspelled as Pachyrucos] belongs to Hegetotheriidae'
- 'Pachyrukhos politus belongs to Pachyrukhos'
- 'Palaeospheniscus nereius belongs to Palaeospheniscus'
- 'Paraptenodytes belongs to Spheniscidae'
- 'Paraptenodytes andrewsi belongs to Paraptenodytes'
- 'Paraptenodytes curtus belongs to Paraptenodytes'
- 'Paraptenodytes grandis belongs to Paraptenodytes'
- 'Physodon belongs to Physeteridae'
- 'Physodon patagonicus belongs to Physodon'
- 'Portheus patagonicus belongs to Portheus'
- 'Prosqualodon belongs to Squalodontidae'
- 'Prosqualodon australis belongs to Prosqualodon'
- 'Simioidea belongs to Mammalia'