Opinions from W. W. Dalquest and G. E. Schultz 1992
- 'Anancus bensonensis is recombined as Cuvieronius bensonensis'
- 'Auchenia vitakeriana is a nomen dubium'
- 'Bison occidentalis is a subjective synonym of Bison bison'
- 'Camelops kansanus is a nomen vanum'
- 'Camelops kansanus is a nomen vanum' according to Hager 1974
- 'Canis edwardii belongs to Canis'
- 'Canis priscolatrans is a subjective synonym of Canis rufus'
- 'Elephas (Euelephas) imperator is recombined as Mammuthus imperator'
- 'Equus (Asinus) calobatus belongs to Equus (Asinus)'
- 'Equus giganteus belongs to Equus'
- 'Equus semiplicatus is a nomen dubium'
- 'Felis fatalis is recombined as Smilodon fatalis'
- 'Felis studeri is recombined as Acinonyx studeri'
- 'Felis trumani is recombined as Acinonyx trumani'
- 'Holomeniscus is a nomen dubium'
- 'Machaerodus floridanus is a subjective synonym of Smilodon fatalis'
- 'Microsorex is a subjective synonym of Sorex' according to George 1988
- 'Microsorex is a subjective synonym of Sorex' according to Diersing 1980
- 'Microsorex is a subjective synonym of Sorex'
- 'Microsorex minutus is recombined as Sorex minutus'
- 'Microsorex minutus belongs to Microsorex' according to Brown 1908
- 'Microsorex pratensis is recombined as Sorex pratensis'
- 'Microsorex pratensis belongs to Microsorex' according to Hibbard 1944
- 'Mictomys is a subjective synonym of Synaptomys'
- 'Mus bursarius is recombined as Geomys bursarius'
- 'Mus pennsylvanicus is recombined as Microtus pennsylvanicus'
- 'Musculus leucopus is recombined as Peromyscus leucopus'
- 'Neosorex is a subjective synonym of Sorex'
- 'Neosorex lacustris is recombined as Sorex lacustris'
- 'Onychomys fossilis is a subjective synonym of Onychomys pedroensis'
- 'Onychomys jinglebobensis is a subjective synonym of Onychomys pedroensis'
- 'Parageomys is a subjective synonym of Geomys'
- 'Parageomys tobinensis is recombined as Geomys tobinensis'
- 'Pedomys is a subjective synonym of Pitymys'
- 'Perognathus hispidus is recombined as Chaetodipus hispidus'
- 'Perognathus hispidus is recombined as Chaetodipus hispidus' according to Hafner and Hafner 1983
- 'Perognathus hispidus belongs to Perognathus' according to Baird 1858
- 'Protocamelus virginiensis is a nomen dubium'
- 'Smilodon californicus is a subjective synonym of Smilodon fatalis'
- 'Smilodon nebraskensis is a subjective synonym of Smilodon fatalis'
- 'Smilodon trinitiensis is a subjective synonym of Smilodon fatalis'
- 'Smilodontopsis conardi is a subjective synonym of Smilodon fatalis'
- 'Smilodontopsis troglodytes is a subjective synonym of Smilodon fatalis'
- 'Sorex hoyi belongs to Sorex'
- 'Sorex hoyi belongs to Sorex' according to George 1988
- 'Spermophilus elegans belongs to Spermophilus'
- 'Spermophilus elegans belongs to Spermophilus' according to Michener and Koeppel 1985
- 'Spermophilus elegans belongs to Spermophilus' according to Fagerstone 1982
- 'Spermophilus elegans is recombined as Citellus elegans' according to Davis 1939
- 'Spermophilus elegans is recombined as Citellus elegans' according to Howell 1928
- 'Tapirus haysii is a nomen dubium'
- 'Tapirus haysii is a nomen dubium' according to Simpson 1945
- 'Tetralophodon barbouri is recombined as Stegomastodon barbouri'
- 'Trucifelis is a subjective synonym of Smilodon'
- 'Urus priscus is recombined as Bison priscus'
- 'Vulpes macrotis belongs to Vulpes'