After Froehlich, 2002
Alternative (older) phylogeny after Hooker, 1989
<==o Hippomorpha Wood, 1937 (hevosmaiset kavioeläimet) |--o †Pachynolophoidea Pavlow, 1888 | `-- †Pachynolophidae Pavlow, 1888 `--o Equoidea Gray, 1821 sensu Hay, 1902 (hevosensukuiset kavioeläimet) |?- †Indolophus Pilgrim, 1925 [Indolophidae Schoch, 1984] |-- †Palaeotheriidae Bonaparte, 1850 `-- Equidae Gray, 1821 (horses; hevoset)
Reference(s):
- Albright III, L. B., 1998: New genus of tapir (Mammalia: Tapiridae) from the Arikareean (Earliest Miocene) of the Texas Coastal Plain.
–Journal of Vertebrate Paleontology: Vol. 18, #1, pp. 200-217 - Badiola, A., Astibia, H., Pereda Suberbiola, X. & Murelaga, X., 2002: First record of the genus Leptolophus Remy, 1965 (Mammalia, Perissodactyla) in the late Eocene (Priabonian) of Europe.
–Geodiversitas: Vol. 24, #4, pp. 841-848 - Froehlich, D. J., 1999: Phylogenetic systematics of basal perissodactyls.
–Journal of Vertebrate Paleontology: Vol. 19, #1, pp. 140-159 - 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 - Hooker, J. J., 1989: Character polarities in early perissodactyls and their
significance for Hyracotherium and infraordinal relationships. 79-101.
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 - 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., 1989: Classification of the Perissodactyla. 530-537.
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 - Schoch, R. M., 1989: A brief historical review of Perissodactyl classification. 13-23.
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 - Thewissen, J. G. M., Williams, E. M. & Hussain, S. T., 2001: Eocene mammals faunas from Northern Indo-Pakistan.
–Journal of Vertebrate Paleontology: Vol. 21, #2, pp. 347-366