After Evander, 1989 and Froehlich, 2002
<==o Equidae Gray, 1821 (horses; hevoset) |?- †Gobihippus |?- †Haplohippus |-- †Sifrhippus sandrae (Gingerich, 1989) Froehlich, 2002 `--+--o †Minihippus Froehlich, 2002 | |-- †M. index (Cope, 1873) [Hyracotherium index Cope, 1873] | `-- †M. jicarillai Froehlich, 2002 `--o †Arenahippus Froehlich, 2002 [a paraphyletic grade-taxa (metataxa) (Froehlich, 2002)] |-- †Arenahippus grangeri (Kitts, 1956) [Hyracotherium angustidens grangeri Kitts, 1956] `--+-- †Arenahippus aemulor (Gingerich, 1991) [Hyracotherium aemulor Gingerich, 1991] `--+-- †Arenahippus pernix (Marsh, 1876) [Eohippus pernix Marsh, 1876] `--+--o †Xenicohippus Bown & Kihm, 1981 | |-- †X. craspedotum (Cope, 1880) [Hyracotherium craspedotum] | `--+-- †X. osborni Bown & Kihm, 1981 | `-- †X. grangeri Bown & Kihm, 1981 `--+-- †Eohippus angustidens (Cope, 1875) Marsh, 1876 [Hyracotherium angustidens Cope, 1875; Eohippus validus Marsh, 1876] `--+-- †Pliolophus vulpiceps Owen, 1858 ["Hyracotherium" vulpiceps] `--o †Protorohippus Wortman, 1896 [a paraphyletic grade-taxa (metataxa) (Froehlich, 2002)] |-- †Protorohippus montanum Wortman, 1896 `--+-- †Protorohippus venticolum (Cope, 1881) [Hyracotherium venticolum Cope, 1881; Hyracotherium vasacciense venticolum (Cope, 1881) sensu Kitts, 1956; incl.? Hyracotherium vasacciense (Cope, 1872)] `--+-- †Protorohippus sp. cf. P. venticolum [Froehlich, 2002] `--+-- †Protorohippus sp. aff. P. venticolum [Froehlich, 2002] `--o †Orohippus Marsh, 1872 [a paraphyletic grade-taxa (metataxa) (Froehlich, 2002)] |?- †Orohippus proteros Korth & Evander, 1982 |?- †Orohippus agilis Marsh, 1873b |?- †Orohippus progressus (Granger, 1908) |?- †Orohippus sylvaticus (Leidy, 1870d) |-- †Orohippus major Marsh, 1874a `--+-- †Orohippus pumilus (Marsh, 1871a) `--+-- †Epihippus gracilis [Duchesnehippus] `--+--o †Mesohippus Marsh, 1875 [Palaeotherium Leidy, 1850; Anchitherium Leidy, 1852; Miohippus Hay, 1902, in partim; Pediohippus Schlaikjer, 1935, in partim] | |-- †M. celer | |-- †M. westoni (Cope, 1889) | |-- †M. bairdi (Leidy, 1850) Marsh, 1875 | |-- †M. exoletus (Cope, 1874) | `-- †M. barbouri Schlaikjer, 1931 `--+--o †Miohippus Marsh, 1874 [Pediohippus] | |-- †M. obliquidens (Osborn, 1904) Prothero & Shubin, 1989 | |-- †M. assiniboiensis (Lambe, 1905b) Prothero & Shubin, 1989 | |-- †M. intermedius (Osborn & Wortman, 1895) | |-- †M. gidleyi (Osborn, 1904) | |-- †M. annectens Marsh, 1874 | |?- †?M. equinanus Osborn, 1918 | |-- †M. gemmarosae | `-- †M. validus `--+-- †Anchitheriinae Leidy, 1869 `-- Equinae Gray, 1821 [non Leidy, 1869, Steinmann & Döderlein, 1890] (true horses; varsinaiset hevoset)
Reference(s):
- Carroll, R. L., 1988: Vertebrate paleontology and evolution.
–W. H. Freeman and company, New York, 1988, 698. - Carroll, R. L., 1988: Appendix. 594-648.
in Carroll, R. L., 1988: Vertebrate paleontology and evolution.
–W. H. Freeman and company, New York, 1988, 698. - Evander, R. L., 1989: Phylogeny of the family Equidae. 109-127.
in Prothero, D. R. & Schoch, R. M., (eds.) 1989: The evolution of perissodactyls.
–Oxford University Press, New York, New York & Oxford, England, 1989, ix-537 - Froehlich, D. J., 2002: Quo vadis eohippus? The systematics and taxonomy of the early Eocene equids (Perissodactyla).
–Zoological Journal of the Linnean Society: Vol. 134, #2, pp. 141-256 - Gazin, C. L., 1976: Mammalian faunal zones of the Bridger Middle Eocene.
–Smithsonian Contributions to Paleobiology: No. 26, pp. iv-2 - Hulbert Jr., R. C., 1989: Phylogenetic interrelationships and evolution of North American Late Neogene Equidae. 176-196.
in Prothero, D. R. & Schoch, R. M., (eds.) 1989: The evolution of perissodactyls.
–Oxford University Press, New York, New York & Oxford, England, 1989, ix-537 - Korth, W. W. & Evander, R. L. 1982: A new species of Orohippus (Perissodactyla: Equidae) from the Early Eocene of Wyoming.
–Journal of Vertebrate Paleontology: vol. 2, #2, pp. 167-171. - McKenna, M. C. & Bell, S. K., (eds.) 1997: Classification of mammals – above the species level.
–Columbia University Press, New York, 1997, xii-631 - Prothero, D. R. & Schoch, R. M. (eds.) 1989: The evolution of perissodactyls.
–Oxford University Press., New York. 1989. - Prothero, D. R. & Shubin, N. H., 1989: The evolution of Oligocene horses. 142-175.
in Prothero, D. R. & Schoch, R. M., (eds.) 1989: The evolution of perissodactyls.
–Oxford University Press, New York, New York & Oxford, England, 1989, ix-537 - Salesa, M. J., Sánchez, I. M. & Morales, J., 2004: Presence of the Asian horse Sinohippus in the Miocene of Europe.
–Acta Palaeontologica Polonica: Vol. 49, #2, pp. 189-196