Pedzisa mutsara unotevera: Mhuka yokutanga yakapiwa zita yakawanikwa muMiocene Mascall Fauna yeCottonwood Creek, Oregon. Zita rokuti "Anchitherium ultimus" rudzi rwacho rwakatsanangurwa muna 1886 nenyanzvi inoona nezvezvinyorwa zvekare, E. D. Cope panguva yainyanya kurwiwa hondo dzeBone. Mukati mokudzidza muna 1906 pamusoro peMascall formation equids, J. Gidley akatamira kurudzi rutsva rwaakatumidza kuti "Archaeohippus". Kufanana kwakasimba kwehunhu kwakakonzera kuti genus iongororwe se subgenus ye "Parahippus" naW. D. Matthew muna 1932. Mukupesana kwakasimba kwepfungwa "Archaeohippus" yakasimbiswazve naDF Bode muna 1933, uye pamwe chete ne "A. ultimus", akabatanidza "A. mourningi" uye "A. penultimus". "Archaeohippus" yakapararira muNorth America yose. Kuwedzera kune zviitiko muFlorida neOregon, zvisaririra zvakawanikwa muSouthern Saskatchewan, Canada. Pamugumo mumwe wokupararira kwawo "Archaeohippus" yakawanwa kure kumaodzanyemba seMiocene Gaillard Cut yomunzvimbomo mu
yaichimbova Panama Canalzone. ""Archaeohippus" stenolophus", inozivikanwa kubva kuOligocene deposits muSaskatchewan, haisi ye "Archaeohippus", uye "A. minimus" inosanganiswa nema taxon maviri, sezvakataurwa naOsborn (1918), neP3-M1 iri ye "A. ultimus" uye molar uye premolar iri yeakakura, akawana equid. "Archaeohippus mannulus" uye "Arachaeohippus blackbergi" zvakafukunurwa muFlorida, zvikurukuru paThomas Farm Site.