Opinions from F. Ameghino 1889
- 'Acaremys messor belongs to Acaremys'
- 'Acyon bardus belongs to Acyon'
- 'Agathodonta belongs to Monotremata'
- 'Anchitherium australe is recombined as Proterotherium australe'
- 'Anicanodonta belongs to Bruta'
- 'Anisolophus is a subjective synonym of Proterotherium'
- 'Anoplotherium americanum is recombined as Proterotherium americanum'
- 'Antifer belongs to Cervidae'
- 'Arctophoca belongs to Phocidae'
- 'Asterostemma belongs to Hoplophoridae'
- 'Asterostemma depressa belongs to Asterostemma'
- 'Asterostemma granata belongs to Asterostemma'
- 'Asterostemma laevata belongs to Asterostemma'
- 'Astrapotherium ephebicum belongs to Astrapotherium'
- 'Atryptheridae belongs to Toxodontia'
- 'Auchenia cordubensis belongs to Auchenia'
- 'Auchenia ensenadensis belongs to Auchenia'
- 'Auchenia injanensis belongs to Auchenia'
- 'Auchenia mesolithica belongs to Auchenia'
- 'Auchenia parallela belongs to Auchenia' according to Ameghino 1884
- 'Auchenia parallela is recombined as Eulamaops parallelus'
- 'Balaena belongs to Balaenidae'
- 'Balaena australis belongs to Balaena'
- 'Balaena dubia belongs to Balaena'
- 'Balaenoptera belongs to Balaenidae'
- 'Balaenoptera antarctica belongs to Balaenoptera'
- 'Balaenoptera bonaerensis belongs to Balaenoptera'
- 'Balaenoptera patachonica belongs to Balaenoptera'
- 'Balanadae is corrected as Balaenidae and belongs to Mystacoceta'
- 'Bothriomys belongs to Hesperomyidae'
- 'Bothriomys catenatus belongs to Bothriomys'
- 'Briaromys belongs to Eryomyidae'
- 'Briaromys trouessartianus belongs to Briaromys'
- 'Bruta belongs to Homalodonta'
- 'Cacodonta belongs to Monotremata'
- 'Callodontomys belongs to Rodentia'
- 'Callodontomys vastatus belongs to Callodontomys'
- 'Camelus pacos is recombined as Auchenia paca'
- 'Canis lydekkeri belongs to Canis'
- 'Capreolus leucotis belongs to Capreolus' according to Gray 1849
- 'Capreolus leucotis is a subjective synonym of Furcifer bisulcus'
- 'Cavia avita belongs to Cavia' according to Ameghino 1887
- 'Cavia avita is recombined as Palaeocavia avita'
- 'Cavia impar belongs to Cavia' according to Ameghino 1888
- 'Cavia impar is recombined as Palaeocavia impar'
- 'Cavia rigens belongs to Cavia' according to Ameghino 1888
- 'Cavia rigens is recombined as Orthomyctera rigens'
- 'Cercolabidae belongs to Hystricomorpha'
- 'Cerodon priscus belongs to Cerodon'
- 'Cerodon pygmeus belongs to Cerodon'
- 'Cerodon turgeo belongs to Cerodon'
- 'Cervus (Cervequus) belongs to Cervus' according to Lesson 1842
- 'Cervus (Cervequus) andicus belongs to Cervus (Cervequus)' according to Lesson 1842
- 'Cervus (Cervequus) andicus is a subjective synonym of Furcifer bisulcus'
- 'Cervus (Furcifer) belongs to Cervus' according to Wagner 1844
- 'Cervus (Furcifer) was reranked as Furcifer and belongs to Cervidae'
- 'Cervus antisensis belongs to Cervus' according to d'Orbigny 1834
- 'Cervus antisensis is recombined as Cervus (Furcifer) antisiensis' according to Wagner 1844
- 'Cervus (Furcifer) antisiensis is a subjective synonym of Furcifer bisulcus'
- 'Cervus aspeitianus is recombined as Blastoceros azpeitianus'
- 'Cervus avius belongs to Cervus' according to Ameghino 1888
- 'Cervus avius is recombined as Paraceros avius'
- 'Cervus campestris is recombined as Blastoceros campestris'
- 'Cervus chilensis belongs to Cervus' according to Gay and Gervais 1846
- 'Cervus chilensis is a subjective synonym of Furcifer bisulcus'
- 'Cervus ensenadensis belongs to Cervus' according to Ameghino 1888
- 'Cervus ensenadensis is recombined as Paraceros ensenadensis'
- 'Cervus fragilis is recombined as Paraceros fragilis'
- 'Cervus intermedius is a subjective synonym of Paraceros avius'
- 'Cervus latus belongs to Cervus'
- 'Cervus minor is a subjective synonym of Paraceros avius'
- 'Cervus paludosus is recombined as Blastoceros paludosus'
- 'Cervus patachonicus is a subjective synonym of Paraceros avius'
- 'Cervus seleniticus is recombined as Furcifer seleniticus'
- 'Cervus sulcatus belongs to Cervus' according to Ameghino 1882
- 'Cervus sulcatus is recombined as Furcifer sulcatus'
- 'Cervus ultra is recombined as Antifer ultra'
- 'Cetacea was reranked as a unranked clade and belongs to Homalodonta'
- 'Chlamydophorina was reranked as the family Chlamydophoridae and belongs to Dasypoda'
- 'Chlamydotheridae belongs to Dasypoda'
- 'Chlamydotherium is a subjective synonym of Glyptodon'
- 'Chlamydotherium belongs to Chlamydotheridae'
- 'Cochlops belongs to Glyptodontidae'
- 'Cochlops muricatus belongs to Cochlops'
- 'Comaphorus belongs to Doedicuridae'
- 'Dasypus hesternus belongs to Dasypus'
- 'Dasypus minutus belongs to Dasypus' according to Desmarest 1822
- 'Dasypus minutus is recombined as Zaedyus minutus'
- 'Dasypus novemcinctus is recombined as Tatusia novemcincta'
- 'Dasypus platensis belongs to Dasypus'
- 'Delotherium belongs to Entelopsidae'
- 'Delotherium venerandum belongs to Delotherium'
- 'Delphinidae belongs to Odontoceta'
- 'Delphinus belongs to Delphinidae'
- 'Delphinus (Grampus) obscurus is recombined as Tursiops obscurus'
- 'Delphinus blainvillei is recombined as Pontoporia blainvillei'
- 'Delphinus coeruleoalbus belongs to Delphinus'
- 'Delphinus rectifrons is recombined as Pontistes rectifrons'
- 'Didelphys grandaeva belongs to Didelphys'
- 'Didelphys juga belongs to Didelphys'
- 'Didelphys lujanensis belongs to Didelphys'
- 'Didelphys triforata belongs to Didelphys'
- 'Dimerodon belongs to Didelphydae'
- 'Dimerodon mutiatus belongs to Dimerodon'
- 'Diplotremus belongs to Oreodontidae'
- 'Diplotremus agrestis belongs to Diplotremus'
- 'Discolomys belongs to Echinomyidae'
- 'Discolomys cuneus belongs to Discolomys'
- 'Ditremata belongs to Mammalia'
- 'Doedicuridae belongs to Glyptodontia'
- 'Doedicurus belongs to Doedicuridae'
- 'Doedicurus antiquus is recombined as Plaxhaplus antiquus'
- 'Doedicurus copei is a subjective synonym of Plaxhaplus antiquus'
- 'Doedicurus kokenianus belongs to Doedicurus'
- 'Doedicurus uruguayensis belongs to Doedicurus' according to Gervais and Ameghino 1880
- 'Doedicurus uruguayensis is a subjective synonym of Doedicurus clavicaudatus'
- 'Dolichotis intermedia belongs to Dolichotis'
- 'Dolichotis lacunosa belongs to Dolichotis' according to Ameghino 1888
- 'Dolichotis lacunosa is recombined as Orthomyctera lacunosa'
- 'Dolichotis platycephala belongs to Dolichotis'
- 'Echidnidae belongs to Cacodonta'
- 'Echinomyidae belongs to Hystricomorpha'
- 'Eleutherocercus belongs to Hoplophoridae'
- 'Entelomorphus belongs to Typotheridae'
- 'Entelomorphus rotundatus belongs to Entelomorphus'
- 'Entelops dispar belongs to Entelops' according to Ameghino 1887
- 'Entelops dispar belongs to Entelops'
- 'Entelopsidae belongs to Pleiodonta'
- 'Epiblema horridula belongs to Epiblema' according to Ameghino 1886
- 'Epiblema horridula is recombined as Neoepiblema horridula'
- 'Epieuryceros is corrected as Epieurycerus and belongs to Cervidae'
- 'Epieuryceros truncus belongs to Epieuryceros'
- 'Equus bisulcus belongs to Equus' according to Molina 1782
- 'Equus bisulcus is recombined as Furcifer bisulcus'
- 'Eryomydae is corrected as Eryomyidae and belongs to Hystricomorpha'
- 'Eulamaops belongs to Camelidae'
- 'Euphilus belongs to Eryomyidae'
- 'Euphilus ambrosettianus belongs to Euphilus'
- 'Euphilus kurtzi belongs to Euphilus'
- 'Euphractus exilis is recombined as Zaedyus exilis'
- 'Euphractus minimus belongs to Euphractus' according to Ameghino 1881
- 'Euphractus minimus is recombined as Zaedyus minimus'
- 'Euphractus patagonicus is recombined as Dasypus patagonicus'
- 'Euphractus proximus is recombined as Zaedyus proximus'
- 'Euryurus is replaced by Neuryurus'
- 'Euryurus antiquus is recombined as Neuryurus antiquus'
- 'Euryurus interundatus is recombined as Neuryurus interundatus'
- 'Felis platensis belongs to Felis'
- 'Globicephalus grayi is recombined as Pseudorca grayi'
- 'Glyptodon belongs to Glyptodontidae'
- 'Glyptodon asper is recombined as Schistopleurum asperum' according to Burmeister 1879
- 'Glyptodon asper is recombined as Hoplophorus asper' according to Cornalia 1872
- 'Hoplophorus asper is a subjective synonym of Glyptodon reticulatus'
- 'Glyptodon asper belongs to Glyptodon' according to Burmeister 1866
- 'Glyptodon clavicaudatus is recombined as Doedicurus clavicaudatus'
- 'Glyptodon dubius belongs to Glyptodon' according to Reinhardt 1875
- 'Glyptodon dubius is a subjective synonym of Glyptodon euphractus'
- 'Glyptodon elevatus belongs to Glyptodon' according to Nodot 1857
- 'Glyptodon elevatus is recombined as Neothoracophorus elevatus'
- 'Glyptodon falkneri belongs to Glyptodon'
- 'Glyptodon fiorinii belongs to Glyptodon'
- 'Glyptodon giganteus belongs to Glyptodon' according to Serres 1865
- 'Glyptodon giganteus is a subjective synonym of Doedicurus clavicaudatus'
- 'Glyptodon gigas belongs to Glyptodon' according to Bravard 1860
- 'Glyptodon gigas is a subjective synonym of Doedicurus clavicaudatus'
- 'Glyptodon gracilis belongs to Glyptodon' according to Nodot 1857
- 'Glyptodon gracilis is recombined as Lomaphorus gracilis'
- 'Glyptodon ornatus is recombined as Hoplophorus ornatus'
- 'Glyptodon radiatus belongs to Glyptodon' according to Bravard 1854
- 'Glyptodon radiatus is a subjective synonym of Lomaphorus elegans'
- 'Glyptodon rudis belongs to Glyptodon' according to Gervais 1878
- 'Glyptodon rudis is recombined as Neuryurus rudis'
- 'Glyptodontia belongs to Hicanodonta'
- 'Glyptodontidae belongs to Glyptodontia'
- 'Habrothrix internus belongs to Habrothrix'
- 'Halobioidea belongs to Ungulata'
- 'Haloboidea belongs to Ungulata'
- 'Hesperomyidae belongs to Myomorpha'
- 'Hesperomys belongs to Hesperomyidae'
- 'Heterodonta was reranked as a unranked clade and belongs to Ditremata'
- 'Hicanodonta belongs to Bruta'
- 'Hipphaplous is corrected as Hipphaplus and belongs to Equidae'
- 'Hippidion angulatus belongs to Hippidion'
- 'Holochilus multannus belongs to Holochilus'
- 'Homalodonta belongs to Ditremata'
- 'Homalodontotheridae belongs to Litopterna'
- 'Homalodontotherium belongs to Homalodontotheridae'
- 'Hoplophorus is a subjective synonym of Glyptodon'
- 'Hoplophorus ameghini is recombined as Plohophorus ameghini'
- 'Hoplophorus australis is recombined as Propalaehoplophorus australis'
- 'Hoplophorus australis belongs to Hoplophorus' according to Moreno 1882
- 'Hoplophorus bergi belongs to Hoplophorus'
- 'Hoplophorus clarazianus belongs to Hoplophorus'
- 'Hoplophorus compressus belongs to Hoplophorus' according to Ameghino 1882
- 'Hoplophorus compressus is recombined as Lomaphorus compressus'
- 'Hoplophorus elegans belongs to Hoplophorus' according to Burmeister 1871
- 'Hoplophorus elegans is recombined as Lomaphorus elegans'
- 'Hoplophorus elevatus belongs to Hoplophorus' according to Ameghino 1883
- 'Hoplophorus elevatus is recombined as Lomaphorus elevatus'
- 'Hoplophorus euphractus is recombined as Glyptodon euphractus'
- 'Hoplophorus evidens belongs to Hoplophorus'
- 'Hoplophorus formosus is a subjective synonym of Hoplophorus lineatus'
- 'Hoplophorus heusseri belongs to Hoplophorus'
- 'Hoplophorus imperfectus belongs to Hoplophorus' according to Gervais and Ameghino 1880
- 'Hoplophorus imperfectus is recombined as Lomaphorus imperfectus'
- 'Hoplophorus lydekkeri belongs to Hoplophorus'
- 'Hoplophorus migoyianus belongs to Hoplophorus'
- 'Hoplophorus minor belongs to Hoplophorus' according to Lund 1838
- 'Hoplophorus minor is recombined as Glyptodon minor'
- 'Hoplophorus sellowi belongs to Hoplophorus' according to Lund 1838
- 'Hoplophorus sellowi is a subjective synonym of Glyptodon euphractus'
- 'Hydrochoerus irroratus belongs to Hydrochoerus'
- 'Hydrothereuta belongs to Heterodonta'
- 'Hyracoidea belongs to Amphidactyla'
- 'Icochilus belongs to Interatheridae'
- 'Icochilus excavatus belongs to Icochilus'
- 'Icochilus extensus belongs to Icochilus'
- 'Icochilus rotundatus belongs to Icochilus'
- 'Icochilus undulatus belongs to Icochilus'
- 'Interatheridae belongs to Toxodontia'
- 'Kerodon [misspelled as Cerodon] belongs to Caviidae'
- 'Lagostomus cavifrons belongs to Lagostomus'
- 'Lagostomus debilis belongs to Lagostomus'
- 'Lagostomus heterogenidens belongs to Lagostomus'
- 'Lagostomus lateralis belongs to Lagostomus'
- 'Lagostomus minimus belongs to Lagostomus'
- 'Lagostomus primigenius belongs to Lagostomus'
- 'Lestodon myloides belongs to Lestodon' according to Gervais 1855
- 'Lestodon myloides is recombined as Pseudolestodon myloides'
- 'Lomaphorus belongs to Hoplophoridae'
- 'Lomaphorus cingulatus belongs to Lomaphorus'
- 'Loricatus hybridus is recombined as Tatusia hybrida'
- 'Macrauchenia media is a subjective synonym of Scalabrinitherium rothii'
- 'Macrauchenia media belongs to Macrauchenia' according to Burmeister 1885
- 'Macrauchenia minuta belongs to Macrauchenia' according to Burmeister 1885
- 'Macrauchenia minuta is a subjective synonym of Oxyodontherium zeballosi'
- 'Macraucheniidae is corrected as Macrauchenidae and belongs to Litopterna'
- 'Macropristis belongs to Macropoda'
- 'Mastodon andium is recombined as Tetrabelodon andium' according to Cope 1884
- 'Mastodon angustidens is a subjective synonym of Mastodon andium'
- 'Mastodon australis belongs to Mastodon' according to Owen 1844
- 'Mastodon australis is a subjective synonym of Mastodon andium'
- 'Mastodon bonaerensis is a subjective synonym of Mastodon platensis'
- 'Mastodon bonaerensis belongs to Mastodon' according to Moreno 1888
- 'Mastodon cordillerarum belongs to Mastodon' according to Desmarest 1822
- 'Mastodon cordillerarum is a subjective synonym of Mastodon andium'
- 'Mastodon cordillerarum [misspelled as Mastodon cordillerum] belongs to Mastodon' according to Lydekker 1886
- 'Mastodon rectus belongs to Mastodon'
- 'Megaptera belongs to Balaenidae'
- 'Megaptera burmeisteri belongs to Megaptera'
- 'Megatherium gervaisi belongs to Megatherium' according to Gervais and Ameghino 1880
- 'Megatherium gervaisi is recombined as Essonodontherium gervaisi'
- 'Mephitis cordubensis belongs to Mephitis'
- 'Mesembriotherium is a subjective synonym of Astrapotherium'
- 'Microcavia uncinata belongs to Microcavia'
- 'Monodontidae belongs to Odontoceta'
- 'Mylodon gracilis is a subjective synonym of Pseudolestodon myloides'
- 'Myopotamus obesus belongs to Myopotamus'
- 'Myrmecophagidae belongs to Vermilinguia'
- 'Mystacoceta belongs to Cetacea'
- 'Necromys belongs to Hesperomyidae'
- 'Necromys conifer belongs to Necromys'
- 'Neoepiblema belongs to Eryomyidae'
- 'Neoepiblema contorta belongs to Neoepiblema'
- 'Neoracanthus brackebuschianus belongs to Neoracanthus'
- 'Neoreomys insulatus belongs to Neoreomys'
- 'Neothoracophorus belongs to Glyptodontidae'
- 'Nesodon magnus is recombined as Astrapotherium magnum'
- 'Nesodon sullivani is recombined as Protoxodon sullivani'
- 'Neuryurus belongs to Doedicuridae'
- 'Notictis belongs to Creodonta'
- 'Notictis ortizii belongs to Notictis'
- 'Odontoceta belongs to Cetacea'
- 'Olenopsis belongs to Echinomyidae'
- 'Olenopsis uncinus belongs to Olenopsis'
- 'Oracanthus is replaced by Neoracanthus'
- 'Oracanthus burmeisteri belongs to Oracanthus' according to Ameghino 1885
- 'Oracanthus burmeisteri is recombined as Neoracanthus burmeisteri'
- 'Orca belongs to Delphinidae'
- 'Orca magellanica belongs to Orca'
- 'Orthomyctera belongs to Caviidae'
- 'Orthomyctera lata belongs to Orthomyctera'
- 'Orthomyctera vaga belongs to Orthomyctera'
- 'Ortotherium belongs to Ortotheridae'
- 'Orycteropodidae [misspelled as Orycteropidae] belongs to Vermilinguia'
- 'Orycterotherium is a subjective synonym of Glyptodon'
- 'Otaria belongs to Phocidae'
- 'Otaria fischeri is recombined as Arctophoca fischeri'
- 'Oxymycterus impexus belongs to Oxymycterus'
- 'Oxyodontherium zeballozi [misspelled as Oxyodontherium zeballosi] belongs to Oxyodontherium'
- 'Pachyrucos absis belongs to Pachyrucos'
- 'Pachyrucos ictus belongs to Pachyrucos'
- 'Pachyrucos naevius belongs to Pachyrucos'
- 'Pachyrucos teres belongs to Pachyrucos'
- 'Pachyrucos trivius belongs to Pachyrucos'
- 'Palaehoplophorus disjunctus belongs to Palaehoplophorus'
- 'Palaeobalaena belongs to Balaenidae'
- 'Palaeobalaena bergi belongs to Palaeobalaena'
- 'Palaeocavia belongs to Caviidae'
- 'Palaeocavia minuta belongs to Palaeocavia'
- 'Palaeocavia pampaea belongs to Palaeocavia'
- 'Palaeohoplophorus is corrected as Palaehoplophorus and belongs to Hoplophoridae'
- 'Palaeolama leptognata belongs to Palaeolama'
- 'Palaeolama owenii is recombined as Stilauchenia owenii'
- 'Palaeolama owenii belongs to Palaeolama' according to Gervais and Ameghino 1880
- 'Palaeolama promesolithica belongs to Palaeolama'
- 'Pampatherium is a subjective synonym of Chlamydotherium'
- 'Pampatherium typus belongs to Pampatherium' according to Ameghino 1875
- 'Pampatherium typus is recombined as Chlamydotherium typum'
- 'Panochthus [misspelled as Panochtus] belongs to Hoplophoridae'
- 'Panochthus frenzelianus [misspelled as Panochtus frenzelianus] belongs to Panochtus'
- 'Panochthus lundi belongs to Panochthus' according to Burmeister 1870
- 'Panochtus lundi is a subjective synonym of Hoplophorus meyeri'
- 'Panochthus nodotianus belongs to Panochthus'
- 'Panochthus voghii belongs to Panochthus'
- 'Paraceros belongs to Cervidae'
- 'Paraceros vulneratus belongs to Paraceros'
- 'Paradoxomyidae belongs to Hystricomorpha'
- 'Paradoxomys belongs to Paradoxomyidae'
- 'Paradoxomys patagonicus belongs to Paradoxomys'
- 'Paranamys typicus is recombined as Olenopsis typicus'
- 'Patriarchus belongs to Interatheridae'
- 'Patriarchus palmidens belongs to Patriarchus'
- 'Peltateloidea belongs to Dasypoda'
- 'Perimys procerus belongs to Perimys'
- 'Perimys scalabrinianus belongs to Perimys'
- 'Phanotherus belongs to Taeniodonta'
- 'Phanotherus marginatus belongs to Phanotherus'
- 'Phoca jubata is recombined as Otaria jubata'
- 'Phocadae is corrected as Phocidae and belongs to Pinnipedia'
- 'Phocaena belongs to Delphinidae'
- 'Phocaena spinipinnis belongs to Phocaena'
- 'Phororhacos longissimus belongs to Phororhacos'
- 'Phororhacosidae belongs to Vermilinguia'
- 'Phorusrhacos is corrected as Phororhacos and belongs to Phororhacosidae'
- 'Physeter belongs to Physeteridae'
- 'Physeter macrocephalus belongs to Physeter'
- 'Physeteridae belongs to Odontoceta'
- 'Pinnipedia was reranked as a unranked clade and belongs to Unguiculata'
- 'Pithanotomys cordubensis belongs to Pithanotomys'
- 'Platanistina was reranked as the family Platanistidae and belongs to Odontoceta'
- 'Plaxhaplous [misspelled as Plaxhaplus] belongs to Doedicuridae'
- 'Plaxhaplus canaliculatus belongs to Plaxhaplus' according to Ameghino 1884
- 'Plaxhaplus canaliculatus belongs to Plaxhaplus'
- 'Pleiodonta belongs to Bruta'
- 'Plexochoerus adluis belongs to Plexochoerus'
- 'Plexochoerus lynchii belongs to Plexochoerus'
- 'Plohophorus belongs to Hoplophoridae'
- 'Plohophorus orientalis belongs to Plohophorus'
- 'Pontistes belongs to Platanistidae'
- 'Pontoporia belongs to Platanistidae'
- 'Praopidae belongs to Dasypoda'
- 'Praopus is a subjective synonym of Tatusia'
- 'Priodonta belongs to Bruta'
- 'Proeuphractus [misspelled as Praeuphractus] belongs to Dasypidae'
- 'Proeuphractus limpidus [misspelled as Praeuphractus limpidus] belongs to Praeuphractus'
- 'Proeuphractus recens [misspelled as Praeuphractus recens] belongs to Praeuphractus'
- 'Propalaehoplophorus belongs to Hoplophoridae'
- 'Propraopus belongs to Praopidae'
- 'Proteroceta belongs to Cetacea'
- 'Protoglyptodon belongs to Hoplophoridae'
- 'Protoxodontidae belongs to Toxodontia'
- 'Protypotherium claudum belongs to Protypotherium'
- 'Pseudoeuryurus belongs to Doedicuridae'
- 'Pseudoeuryurus lelongianus belongs to Pseudoeuryurus'
- 'Pseudolestodon injunctus belongs to Pseudolestodon'
- 'Pseudorca belongs to Delphinidae'
- 'Ptyssophorus belongs to Hesperomyidae'
- 'Ptyssophorus elegans belongs to Ptyssophorus'
- 'Saurocetes belongs to Zeuglodonta'
- 'Saurocetes argentinus belongs to Saurocetes'
- 'Schistopleurum is a subjective synonym of Glyptodon'
- 'Schistopleurum typus belongs to Schistopleurum' according to Nodot 1857
- 'Schistopleurum typus is recombined as Glyptodon typus' according to Gervais and Ameghino 1880
- 'Glyptodon typus is a subjective synonym of Glyptodon reticulatus'
- 'Sclerocalyptus verus belongs to Sclerocalyptus'
- 'Scotaeops belongs to Orycteropidae'
- 'Scotaeops simplex belongs to Scotaeops' according to F. Ameghino 1887
- 'Sirenia belongs to Halobioidea'
- 'Smilodon neogaeus is a subjective synonym of Smilodon populator'
- 'Spondilocoelia belongs to Monotremata'
- 'Stegotheridae belongs to Peltateloidea'
- 'Stegotherium belongs to Stegotheridae'
- 'Stereopterna belongs to Perissodactyla'
- 'Stilauchenia belongs to Camelidae'
- 'Tatusia belongs to Praopidae'
- 'Thoracophorus depressus belongs to Thoracophorus' according to Ameghino 1881
- 'Thoracophorus depressus is recombined as Neothoracophorus depressus'
- 'Thoracophorus minutus belongs to Thoracophorus' according to Ameghino 1881
- 'Thoracophorus minutus is recombined as Neothoracophorus minutus'
- 'Toxodon patagonensis is a subjective synonym of Protoxodon sullivani'
- 'Toxodontherium reverendum belongs to Toxodontherium'
- 'Toxodontia belongs to Amphidactyla'
- 'Toxodontidae belongs to Toxodontia'
- 'Toxodontophanus is a subjective synonym of Protypotherium'
- 'Toxodontophanus australis is recombined as Protypotherium australis'
- 'Tretomys belongs to Hesperomyidae'
- 'Tretomys atavus belongs to Tretomys'
- 'Trichechidae belongs to Pinnipedia'
- 'Tursiops belongs to Delphinidae'
- 'Tursiops cymodoce belongs to Tursiops'
- 'Typotheriidae is corrected as Typotheridae and belongs to Toxodontia'
- 'Unguiculata belongs to Heterodonta'
- 'Ungulata belongs to Heterodonta'
- 'Vermilingua [misspelled as Vermilinguia] belongs to Anicanodonta'
- 'Xotodontidae belongs to Toxodontia'
- 'Zaedyus belongs to Dasypidae'
- 'Zamicrus belongs to Megatheriidae'
- 'Zamicrus admirabilis belongs to Zamicrus'
- 'Zaphilus belongs to Hoplophoridae'
- 'Zaphilus larranagai belongs to Zaphilus'
- 'Zeuglodonta belongs to Hydrothereuta'
- 'Ziphiidae belongs to Odontoceta'
- 'Ziphiorrhynchus australis belongs to Ziphiorrhynchus' according to Burmeister 1866
- 'Ziphiorrhynchus australis is recombined as Ziphius australis'
- 'Ziphius belongs to Ziphiidae'