Elizabeth Schramm, age 10, of Bethlehem, Pa., for her question:

ARE HORSES NATIVE TO THE UNITED STATES?

Scientists figure that 50 million years ago there were horses on the plains of the Western United States, but they

were not like today's horses. The ancient horse was as big as a fo  and had toes instead of hooves. But the fo  like horse disappeared from North America.

North American Indians probably had never seen horses until the Spanish  explorers under Hernando Cortez came to Mexico in 1519. The wild horses found later on the Western plains were most likely descendants of the horses belonging to those early visitors.