Opinions from T. S. Kelly and E. B. Lander 1988

  • 'Astrohippus albidens is recombined as Dinohippus albidens'
  • 'Griphippus is a subjective synonym of Pseudhipparion'
  • 'Hipparion gratum is recombined as Pseudhipparion gratum'
  • 'Hippidium interpolatum is recombined as Dinohippus interpolatus'
  • 'Hippidium spectans is recombined as Dinohippus spectans'
  • 'Hippotherium calamarium is recombined as Stylonus calamarius'
  • 'Hippotherium calamarium is recombined as Neohipparion calamarius' according to Trouessart 1905
  • 'Hippotherium isonesum is recombined as Stylonus isonesus'
  • 'Hippotherium isonesum is a subjective synonym of Merychippus seversus'
  • 'Hippotherium retrusum is recombined as Pseudhipparion retrusum'
  • 'Hypsiops leptoscelos is recombined as Merychyus leptoscelos'
  • 'Mediochoerus blicki is a subjective synonym of Mediochoerus mohavensis'
  • 'Merychippus californicus is recombined as Stylonus californicus'
  • 'Merychippus californicus belongs to Merychippus' according to J. Merriam 1915
  • 'Merychippus carrizoensis is recombined as Stylonus carrizoensis'
  • 'Merychippus isonesus quintus is recombined as Stylonus quintus'
  • 'Merychippus missouriensis is recombined as Stylonus missouriensis'
  • 'Merychippus praecocidens is a subjective synonym of Stylonus isonesus'
  • 'Merychippus stylodontus is recombined as Stylonus stylodontus'
  • 'Merychippus sumani belongs to Merychippus'
  • 'Merychippus sumani is a subjective synonym of Merychippus stylodontus' according to Bernor et al. 1980
  • 'Merychippus tehachapiensis is a subjective synonym of Stylonus carrizoensis'
  • 'Merychyus (Metoreodon) relictus is recombined as Merychyus relictus'
  • 'Merychyus arenarum is a subjective synonym of Merychyus elegans'
  • 'Merychyus calaminthus is a subjective synonym of Merychyus elegans'
  • 'Merychyus calimontanus is a subjective synonym of Merychyus elegans'
  • 'Merychyus crabilli belongs to Merychyus'
  • 'Merychyus delicatus is a subjective synonym of Merychyus elegans'
  • 'Merychyus euryops is a nomen nudum'
  • 'Merychyus jahnsi is a subjective synonym of Merychyus elegans'
  • 'Merychyus major belongs to Merychyus'
  • 'Merychyus medius belongs to Merychyus'
  • 'Metoreodon novomexicanus is a subjective synonym of Merychyus medius'
  • 'Merychyus minimus is recombined as Merychyus elegans minimus' according to Peterson 1923
  • 'Merychyus minimus is a subjective synonym of Merychyus elegans'
  • 'Merychyus paniensis is a subjective synonym of Merychyus elegans'
  • 'Merychyus smithi is recombined as Merychyus elegans smithi'
  • 'Merychyus verrucomalus is a subjective synonym of Merychyus elegans'
  • 'Merycochoerus (Brachycrus) was reranked as Brachycrus and belongs to Merycoidodontidae'
  • 'Merycochoerus altiramus is a subjective synonym of Brachycrus laticeps'
  • 'Merycochoerus buwaldi is a subjective synonym of Brachycrus laticeps'
  • 'Merycochoerus coenopus is a subjective synonym of Merychyus medius'
  • 'Merycochoerus coenopus belongs to Merycochoerus' according to Scott 1890
  • 'Merycochoerus elrodi is a subjective synonym of Brachycrus laticeps'
  • 'Merycochoerus laticeps is recombined as Brachycrus laticeps'
  • 'Merycochoerus madisonius is a subjective synonym of Brachycrus laticeps'
  • 'Merycochoerus obliquidens is a subjective synonym of Ticholeptus zygomaticus'
  • 'Merycochoerus rusticus is recombined as Brachycrus rusticus'
  • 'Pliohippus edensis is recombined as Dinohippus edensis'
  • 'Pliohippus leidyanus is recombined as Dinohippus leidyanus'
  • 'Pliohippus lullianus belongs to Pliohippus'
  • 'Pliohippus osborni is recombined as Dinohippus osborni'
  • 'Poatrephes is a subjective synonym of Ticholeptus'
  • 'Poatrephes paludicola is a subjective synonym of Ticholeptus zygomaticus'
  • 'Pronomotherium siouense is a subjective synonym of Brachycrus laticeps'
  • 'Protohippus coalingensis is recombined as Dinohippus coalingensis'
  • 'Protohippus fossulatus is recombined as Dinohippus fossulatus'
  • 'Protohippus sejunctus is recombined as Stylonus sejunctus'
  • 'Protohippus supremus is recombined as Pliohippus supremus'
  • 'Stylonus belongs to '
  • 'Stylonus seversus belongs to Stylonus'
  • 'Ticholeptus belongs to Merycoidodontidae'
  • 'Ticholeptus hypsodus is a subjective synonym of Ticholeptus zygomaticus'
  • 'Ticholeptus rileyi is a subjective synonym of Ticholeptus zygomaticus'
  • 'Ticholeptus tooheyi is a subjective synonym of Merychyus elegans'
  • 'Ticholeptus zygomaticus belongs to Ticholeptus'
  • 'Ustatochoerus schrammi is a subjective synonym of Ticholeptus zygomaticus'