DINOSAURS LIVED MANY YEARS AGODinosaurs lived on the earth for 135 million years. They appeared 200 million years ago, and they disappeared 65 million years ago. They were the largest animals ever to live on earth, and they ruled the earth for a very long period of time. Dinosaurs lived in North America, in Africa, and in Europe. During this time, the land in North America was under a large, shallow sea. Many dinosaurs lived in the water, which helped to hold up their great weight. The early dinosaurs walked on two feet, and they ate meat. The later dinosaurs were larger and walked on four feet. Some of the later dinosaurs ate plants only. The Stegosaurus was very large. It was a plant eater, but it was often in danger from the meat-eating dinosaurs. It developed scales along its back to protect itself. The Stegosaurus was so large that it took a long time for messages to travel from its brain to its legs. To solve this problem, it developed a “second brain” by its back legs to control its leg movements. Why did dinosaurs die out? Nobody knows for sure. Probably a change in the weather made serious problems for them. About 70 million years ago, The Rocky Mountains formed in North America. The plant life and the weather changed. Perhaps the dinosaurs couldn’t change fast enough. People who like dinosaurs can see fossils in Dinosaur National Park. This park is in Utah and Colorado. Fossils are bones which have become stone. Fossils have taught us a lot about these great animals of the past.
DRY LAND FARMING: AN ART AND A SCIENCE Before modern farming methods, farmers lost many crops to dry weather. Sometimes dry periods lasted for many years. In those days, a long dry period, or drought, often turned the land to dust. Then winds came along and blew the good land away. This happened year after year. Farmers didn’t understand how to plant and so they made the situation worse. Each year they planted the same crops. They never gave the land a rest. The land became poor with to much use. They always planted in long, straight rows. They broke the land into fine dust. They never planted trees to break the strength of the wind. The worst dry period was the drought of the 1930’s. Good farmland on the Western Plains became a Dust Bowl. Farmers had a very hard time until they started to use modern farming methods. Now farmers plant a different crop every year. Some years they give part of their land a rest. The land stays healthy and rich. Modern farmers form rows in curving lines and plant trees to stop the wind. Modern crops are much larger and more dependable. Dry land farming is both a science and an art. From the air, the farms look like pieces of modern art.
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