Opinions from C. Paula Couto 1956
- 'Abothrodon belongs to Haplodontheriinae'
- 'Abothrodon pricei belongs to Abothrodon'
- 'Cavioidea belongs to Hystricomorpha'
- 'Cuvieroniinae belongs to Gomphotheriidae'
- 'Elephantoidea belongs to Proboscidea'
- 'Eremotherium belongs to Megatheriinae'
- 'Eumegamyinae belongs to Heptaxodontidae'
- 'Glyptodontidae belongs to Glyptodontoidea'
- 'Glyptodontoidea belongs to Cingulata'
- 'Gomphotheriidae belongs to Elephantoidea'
- 'Haplodontheriidae was reranked as the subfamily Haplodontheriinae and belongs to Toxodontidae'
- 'Haplomastodon belongs to Cuvieroniinae'
- 'Haplomastodon waringi belongs to Haplomastodon' according to Holland 1920
- 'Haplomastodon waringi belongs to Haplomastodon'
- 'Heptaxodontidae belongs to Cavioidea'
- 'Hystricomorpha belongs to Rodentia'
- 'Iniinae belongs to Platanistidae'
- 'Lestodon belongs to Lestodontinae'
- 'Lestodon armatus belongs to Lestodon'
- 'Lestodontinae belongs to Mylodontidae'
- 'Megatheriadae is corrected as Megatheriidae and belongs to Megatherioidea'
- 'Megatheriinae belongs to Megatheriidae'
- 'Megatherioidea belongs to Pilosa'
- 'Mylodontidae belongs to Mylodontoidea'
- 'Mylodontoidea belongs to Pilosa'
- 'Neotrigodon belongs to Haplodontheriinae'
- 'Neotrigodon utoquineae belongs to Neotrigodon' according to Spillman 1949
- 'Odontoceti belongs to Cetacea'
- 'Phoberomys belongs to Eumegamyinae'
- 'Phoberomys bordasi belongs to Phoberomys' according to Patterson 1942
- 'Phoberomys bordasi belongs to Phoberomys'
- 'Pilosa belongs to Xenarthra'
- 'Platanistina was reranked as the family Platanistidae and belongs to Platanistoidea'
- 'Platanistoidea belongs to Odontoceti'
- 'Plicodontinia belongs to Iniinae'
- 'Plicodontinia mourai belongs to Plicodontinia'
- 'Scelidotheriinae was reranked as the subfamily Scelidotheriidae and belongs to Mylodontoidea'
- 'Scelidotherium belongs to Scelidotheriidae'
- 'Toxodon belongs to Toxodontidae'
- 'Toxodontia [misspelled as Toxodonta] belongs to Notoungulata'
- 'Toxodontidae belongs to Toxodonta'
- 'Trichechiformes belongs to Sirenia'
- 'Trichechus belongs to Trichechidae'
- 'Trichecidae is corrected as Trichechidae and belongs to Trichechiformes'
- 'Trigodonops belongs to Haplodontheriinae'
- 'Trigodonops lopesi belongs to Trigodonops' according to Roxo 1821
- 'Trigodonops lopesi belongs to Trigodonops'
- 'Xenarthra belongs to Edentata'