ROCKS AND SOIL 



This huge reptile-like Brontosaurus lived on plants and grew to be 60 feet long. 

 It must have weighed 30 to 40 tons. Notice the skeleton of the man in the upper 



picture. 



bones, are found in the rock. In the far west, great 

 skeletons of extinct animals have been dug up. One of 

 these is that of a huge vegetarian called the Brontosaurus, 

 which was 60 feet long and weighed 30 tons. But skeletons 

 of still larger animals have been uncovered ; for example, 

 a great elephant-like creature, the Atlantosaurus, 100 

 feet long and weighing 100 tons. In some parts of the 

 world the fossils of flying reptiles and even ancient insects 

 have been discovered. Some of the dragon flies found 

 had a wing spread of two feet. 



Changes in Life on the Earth. One very evident thing 

 comes from the study of these fossils. That is, that the 

 earliest forms of animals were very simple. Then the earth 

 became peopled with many water-living forms, mostly 



