Cassandra Kellog, age 13, of Jamestown, N.Y., for her question:
WERE THERE PREHISTORIC HORSES?
Scientists tell us that the earliest ancestor of the horse was a small animal about 10 to 20 inches high. It lived in what is now North America and Europe about 55 million years ago.
These prehistoric horses had arched backs and snoutlike noses. They looked more like racing dogs, such as greyhounds or whippets, than like the straight backed, long backed modern horse. They had four toes on their front feet and three toes on their hind feet.
The next important ancestor of the modern horse was the Mesophippus, or middle horse. It lived about 35 million yers ago. Mesophippus averaged about 20 inches in height and had long, slender legs. Each foot had three toes, of which the middle toe was longest.
About 30 million years ago, Mesophippus gave way to a new horse like creature, the Miohippus. This animal stood from 24 to 28 inches tail and its middle toe was longer and stronger than that of its ancestors.
Horse like animals continued to develop. The Merychippus, a ruminant or cud chewing horse, appeared about 26 million years ago. It grew about 40 inches high. Like Miohippus, it had three toes on each foot. The side toes were almost useless, but the center toe grew long and strong. It ended in a large, curved hoof, and bore all the animal's weight.
But about one million years ago, horses most likely looked somewhat like modern horses. They grew larger than their ancestors. The side toes on their feet became short bones along the legs, leaving the strong center toe with its hoof to support the animals.
The horse of a million years ago developed teeth that were better fitted for eating grass. Scientists group these horses, along with the modern domestic horse, under the name Equus.
No one knows exactly where horses originated. Fossils show that during the Ice Age horses lived on every continent except Australia.
At one time, great herds of horses wandered throughout North and South America. Then for some unknown reason, horses disappeared from the Western Hemisphere.
Primitive man hunted horses and ate their meat. No one knows who first tamed horses and trained them for riding. But scientific discoveries at the ancient city of Susa in western Iran show that man rode horseback more than 5,000 years ago.
Ancient records show that the Hittities trained horses for sport and war about 1400 B.C. and about 800 B.C. the Assyrians hunted lions in two wheeled chariots drawn by a pair of horses.
The ancient Greeks and Romans were expert horsemen and used horses for racing and other sports. The Greek and Roman soldiers also rode horses in battle.
The first European colonists found no horses in North America. The American Indians did not know about horses until Spanish conquistadores brought them to Mexico in 1519. The Spaniards and later explorers left some of their horses behind. The Spanish horses probably became the ancestors of the American wild horses.