These animals, which are grouped with the horse among the odd-toed (perissodactyl) mammals, are now verging toward extinction.
In the year 1898 the family had to buy a new set of harness for the perissodactyl.
The fifth digit, for the same reasons as in the perissodactyl foot, first left the ground and became smaller.
The great group is now usually divided into those that are odd-toed (perissodactyl) and those that are even-toed (Artiodactyl).
Or, to put it more definitely: hoofed animals are divided into two groups, even-toed (artiodactyl) and odd-toed (perissodactyl).
Perissodac′tyl, Perissodac′tylate, perissodactyl′ic, Perissodac′tylous.
Any of various hoofed mammals of the order Perissodactyla, having one or three hoofed toes on each hindfoot. During the Tertiary Period, perissodactyls were the dominant herbivorous fauna. Horses, tapirs, and rhinoceroses are perissodactyls. Also called odd-toed ungulate.