Odd-toed ungulates, in comparison to even-toed ungulates, bear the majority of weight on one toe only; their third toe. The other difference between the two ungulate families, is that odd-toed ungulates digest cellulose in their intestines, not their stomach. The odd-toed ungulate family is rather small, consisting of horses, donkeys, tapirs, and rhinoceros. Despite the size of this family, odd-toed ungulates have an extensive reach and are present across the globe, due to establishment of feral populations. Two of the odd-toed ungulate species have been domesticated; horses and donkeys. All odd-toed ungulates are either large to very large, with the smallest still weighing in at 200 kg or 440 lbs.
There are about 17 species of odd-toed ungulates. Animals that are odd-toed ungulates include the javan rhinoceros, mountain tapir, mountain zebra, onager, kiang, mule, donkey, and horse. Other animals include the Sumatran rhinoceros, African wild ass, and Malayan tapir.
Shared characteristics of odd-toed ungulates include them being herbivores and each having 1 or 3 hoofed toes on each hindfoot. They also have a long upper jaw and a reduced ulna and fibula bones simplifying both the wrist and ankle joint. They don’t have a clavicle bone making running more efficient.
The most notable difference between even and odd-toed ungulates is the number of toes they have. Odd-toed ungulates have an odd number of toes, while even-toed ungulates have an even number of toes (2 or 4). Odd-toed ungulates are able to digest plant matter in their intestines, while even-toed ungulates digest their meals in one or more stomach chambers.