MENU - PERISSODACTYLA
Class: Mammalia (mammals)
Subclass: Eutheria (placental mammals)
Order: Perissodactyla (horses, tapirs, and rhinoceroses)
Family: Equidae (horses)
Perissodactyla literally means "odd-toed." This order is comprised of the horses, rhinos, and tapirs. The name originates from the fact that most species have three toes on the hindfoot and three or four on the forelimbs. Some species only possess a single toe. The middle toe is generally larger than its counterparts. About 60 million years ago, this dominant group was represented by 14 scientific families. That diverse group of animals has now been reduced to only 3 remaining families and 18 recognized species. Several members of this order are highly endangered and face many environmental challenges. Their overall decline appears to be related to the rise of the even-toed ungulates. Modern species are native to Africa, south and central Asia, southern North America, and northern South America.
A few species possess horns, but these are derived from the epidermis. Perissodactyls differ from artiodactyls in the fact that their horns are not supported by bone tissue. Artiodactyls also possess paired horns. Perissodactyls have a simple stomach, while their even-toed counterparts tend to feature a chambered stomach. These animals have up to 44 large cheek teeth that are specially designed to process their highly herbivorous diet. An enlarged cecum may contribute to the effective digestion of plant material.
Myers, P. 2001. "Perissodactyla" (On-line), Animal Diversity Web. Accessed January 24, 2005 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Perissodactyla.html.