A hoofed mammal of an order that includes horses, rhinoceroses, and tapirs. Mammals of this group have either one or three toes on each foot.
- ‘The horse's single toe on each of its four feet is its most marked anatomical characteristic and makes it a perissodactyl or odd-toed ungulate.’
- ‘Even- and odd-toed ungulates are the predominant large mammalian herbivores in most of the world today.’
- ‘Artiodactyls stand in contrast to the ‘odd-toed ungulates,’ the Perissodactyla, in which the plane of symmetry runs down the third toe.’