An odd-toed ungulate is a mammal with hooves that feature an odd number of toes. Odd-toed ungulates comprise the order Perissodactyla (Greek: περισσός, perissós, "uneven", and δάκτυλος, dáktylos, "finger/toe"). The middle toe on each hoof is usually larger than its neighbours. Odd-toed ungulates are relatively large grazers and, unlike the ruminant even-toed ungulates (artiodactyls), they have relatively simple stomachs because they are hindgut f...
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An odd-toed ungulate is a mammal with hooves that feature an odd number of toes. Odd-toed ungulates comprise the order Perissodactyla (Greek: περισσός, perissós, "uneven", and δάκτυλος, dáktylos, "finger/toe"). The middle toe on each hoof is usually larger than its neighbours. Odd-toed ungulates are relatively large grazers and, unlike the ruminant even-toed ungulates (artiodactyls), they have relatively simple stomachs because they are hindgut fermenters, digesting plant cellulose in their intestines rather than in one or more stomachs. Odd-toed ungulates include the horse, tapirs, and rhinoceroses.
Although no certain fossils are known prior to the early Eocene, the odd-toed ungulates probably arose in what is now Asia, during the Paleocene-Eocene boundary (55 Ma).
By the start of the Eocene (55 million years ago) they had diversified and spread out to occupy several continents. Horses and tapirs both evolved in North America; rhinoceroses appear to have developed in Asia from tapir...
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