La preuve de Othniel Charles Marsh
En fait, on s’est aperçu ensuite que l’arbre est le suivant :
The is a brief description of the tree for those who are visually impaired. Hyracotherium is shown giving rise to three lineages. Two lineages quickly go extinct. The third branches many times. There are many branches alive during most times until two million years ago when only the various species of Equus remain. The tree itself is unreadable to those who are visually impaired so skip the tree graphic.
2My Old & New World Equus \ | /
\ | /
4My Hippidion Equus Stylohipparion | | Neohipparion Hipparion Cormohipparion | | Astrohippus | | |
| | Pliohippus --- 12My Dinohippus Calippus \ | /
| | Pseudhipparion \ | / | | | |
--- Sinohippus 15My \ | / |
\ | / Megahippus | 17My Merychippus | | | Anchitherium Hypohippus | | |
23My Parahippus Anchitherium Archeohippus
| | | (Kalobatippus?)--- 25My \ | /
\ | / | 35My |
Miohippus Mesohippus | | 40My Mesohippus | | | 45My Paleotherium |
| Epihippus | |
Propalaeotherium | Haplohippus | | |
50My Pachynolophus | Orohippus | | | | | | --- \ | / \ | / 55My Hyracotherium