Fossils: Numbers on the Pages of Time (PA-13)
Since prehistoric time, man has been fascinated by fossils, and our modern understanding of them makes them more than just curiosities. Fossils, of course, represent life of the geologic past, either plant or animal life, preserved in many different ways. Because life was constantly changing, different rock units contain different assemblages of fossils. These changes with time give us a way of comparing and contrasting the relative ages of different layers of rock. Thus fossils serve as a yardstick to measure geologic time. Fossils also tell us about the environment in which the animals or plants lived, whether on land or in the sea, in deep water or shallow, in a warm climate or a cold one. To the scientist and the amateur fossil hunter alike, the rocks of Indiana provide a fertile field for collecting and studying fossils.

Our Hoosier State Beneath Us: Paleontology