Parahippus_leonensisHippidionOnohippidiumEquusDinohippusAstrohippusPliohippusM_carrizoensisM_stylodontusProtohippusCalippusM_intermontanusMerychippus_isonesusM_sejunctusM_coloradensePseudhipparionNeohipparionM_insignisHipparionM_goorisiCormohipparionNannippusM_primusM_gunteriOsteologyMaximum ParsimonyBased on reanalysis of the original matrix.Hulbert_1989a