Pliohippus pernix (Marsh, 1874) Dataset GBIF Backbone Taxonomy Rank SPECIES Classification kingdom Animalia phylum Chordata class Mammalia order Perissodactyla family Equidae genus Pliohippus species Pliohippus pernix Name Synonyms Hippidium pernix (Marsh, 1874) Hippidium robustus (Marsh, 1874) Pliohippus lullianus (Troxell, 1916) Pliohippus robustus (Marsh, 1874) Protohippus pernix (Marsh, 1874) Protohippus robustus (Marsh, 1874) Homonyms Pliohippus pernix (Marsh, 1874)