<==o PERISSODACTYLA Owen, 1848 sensu McKenna and Bell, 1997 [Mesaxonia, Perissodactylomorpha] (kavioeläimet)
   |-- HIPPOMORPHA (hevosmaiset kavioeläimet)
   `--o CERATOMORPHA Wood, 1937 [Meropomorpha] (sarvikuonomaiset kavioeläimet)
      |--o †SELENIDA
      |  |-- †BRONTOTHEROIDEA
      |  `-- †CHALICOTHEROIDEA
      `--o TAPIROMORPHA (tapiirimaiset kavioeläimet)
         |-- RHINOCEROTOIDEA (sarvikuononsukuiset kavioeläimet)
         `--+-- †Heptodon calciculus
            `--o TAPIROIDEA (tapiirinsukuiset kavioeläimet)
               |-- †Isectolophidae
               `--+-- †Helaletidae [paraphyletic?]
                  |-- †Lophiodontidae
                  |-- †Deperetellidae [incl. Rhodopagidae]
                  |-- †Lophialetidae [incl. Eoletidae]
                  `-- Tapiridae Burnett, 1830 (tapiirit)


Reference(s):

   Froelich, D. J., 1999: Phylogenetic systematics of basal perissodactyls.
–Journal of Vertebrate Paleontology: Vol. 19, #1, pp. 140 - 159       

	Holbrook, L. T., 2001: Comparative osteology of early Tertiary tapiromorphs
(Mammalia; Perissodactyla)
–Zoological Journal of the Linnean Society: Vol. 132, #1, pp. 1-54


McKenna, M. C. & Bell, S. K., eds., 1997:
Classification of mammals; above the species level.

--Columbia University Press, New York, 1997.
   

   Prothero, D. R. & Schoch, R. M. 1989: Classification of the Perissodactyla. 530-537.
In Prothero, D. R. & Schoch, R. M. 1989: The evolution of perissodactyls.
--Oxford University Press., New York. 1989.