“And so you might find the descendants of Paleo-mastodon in Europe in the Miocene Period, after the land bridges were made, but not earlier.”
“Yes, I see.”
“That’s exactly what happened. In the Lower Miocene of Europe is found the Trilophodon or four-tusked Mastodon. The European form is older and less developed than the four-tusked Mastodon of America, but the little fellow traveled from Africa to China, going through Arabia, and from Africa to Florida by way of the Behring Straits land bridges. They weren’t straits, then, of course.
“So, in that warm corner of Africa, the elephants slowly began to develop until the time of Paleo-mastodon and later, going on their own way without any interference from others. They managed to defend themselves from the creodonts and, little by little, developed trunks and tusks. Then came the land opening into Europe and Asia, and, like a stream bursting through a dam, the four-tusked Mastodons scattered to the four corners of the earth, trumpeting as they went.
“They grew more and more powerful. Soon the little four-tusked fellow decided to give all his attention to the development of his upper tusks and to let the lower ones go. One type, which we call the Beaked Mastodon, had a short jaw and his lower tusks turned down. It wasn’t a very good arrangement and his kind became extinct. The other two types are distinguished by a difference in the teeth—”
“Teeth again!” exclaimed Perry.
“Exactly. One had four crests on the second molar, the other had three, but it was the three-crested type that had the first success and the three-crested style that led to the modern Mastodon. The first big Tertiary two-tusked Mastodon, who is called Dibelodon, had the three-crested tooth, and he spread everywhere. All the South American Mastodons were of his race.
“Meantime, another of the family decided to develop the lower tusks, instead of the upper, and they stuck downwards at right angles to the lower jaw. If you can imagine an exaggerated walrus tusk effect, only coming from the lower jaw, instead of from the upper, you can get some idea of it.”
“What a queer-looking brute! What would be the use of tusks like that?”
“For roots,” his uncle replied. “It worked fairly well, for the family succeeded for a long time, too. The biggest specimen of Dinotherium, which was found in Roumania, was bigger than the largest Mastodon. But the Dinothere didn’t have the real emigration spirit. So far as we know, he never came to the New World.