Steve Hall, age 12, of Williamsport, Penna., for his question:

What is a mastodon?

The mastodon was a remote relative of the elephant and he has his own branch on the fascinating elephant family tree. He thrived in North America until perhaps a thousand years ago. His fossil remains have been found in many places throughout the United States and Canada. He was very like a modern elephant, though a little shorter and his body was longer. The mastodon was a browsing animal who enjoyed the leafy foliage that flourished in the swamps of the last Ice Age.

The family history of the elephant goes back at least 50 or 60 million years. The elephant ancestors lived in Egypt when the horse ancestors were just getting started in the New World. The original ancestors were only 25 inches tall and had no tusks or no trunk. Nevertheless, the experts tell us that these little animals had the characteristics which made them elephants.

In a few million years, the descendants of the original elephants had become more than three feet tall. Their fossil remains show that a long nose was beginning to develop though the teeth were still normal. In the New World, the little horse was growing bigger and learning to stand on tiptoe. As time passed, the members of the elephant family grew bigger and bigger. They also grew long lower jaws and two upper teeth began to look like tusks.

Some 25 million years ago, the elephants had reached their full size, However, they still had the long lower jaw and four long tusks instead of two. These powerful animals were roamers. They traveled into Europe, into Asia and somehow they got to North America. To do this, they may have crossed a land bridge from Northern Europe to Canada, or another land bridge from Asia to Alaska.

From this time almost until the present, there were many kinds of elephants in the New World. The huge imperial elephant roamed through California, Texas and Mexico. This fellow stood two feet taller than ours modern Jumbo aril his great curved tusks were 16 feet long. The Columbian elephants a little larger than a modern Indian elephant, had spiral tusks, often overlapping at the tips. By this time the four tusked elephants had disappeared and the lower jaw had become much smaller. All the elephants now had two tusks and a long, pliable trunk.

To the north, in Arctic regions, lived the woolly mammoth. He was somewhat smaller than a modern elephant but he may have looked bigger because he was covered with a floor length coat of coarse hair. To the south lived the mastodon, feeding on trees and shrubs and perhaps wading in the swampland. He was two feet shorter and more than a foot longer than a modern Jumbo. He was hunted by Indians and was most likely here when Leif Ericson visited America,