Parahippus_leonensisMerychippus_primusMerychippus_insignisCormohipparion_goorisiCormohipparion_quinniCormohipparion_frickiCormohipparion_skinneriCormohipparion_johnsoniCormohipparion_merriamiCormohipparion_matthewiCormohipparion_occidentaleLACM_150080Hippotherium_primigeniumOsteologyMaximum ParsimonyBased on reanalysis of the original matrix.Woodburne_2007a