Great Index Fossils Tell a Tale

Index fossils are very important to geologists because they help to tell the tale of our Earth’s history. Geologists use these specific fossils to determine the relative age of rock layers and to correlate those rock layers worldwide. Sound far-fetched? It isn’t really. Some fossils have such unique characteristics that if you find them, you know exactly where you are in the age of Earth. Good index fossils lived for only a short period of time but lived all over the world.