Don't you ever wonder how earth was millions of years of ago ? Fossils are extinct organisms that lived long ago. Paleontologists help us learn about the earth along time ago by digging up fossils and studying them. There are many fossils all around the world there are shell fossils, dinosaurs fossils, fish fossils, bird fossils, plant fossils, and insects fossils. There are four main types of fossils they are body fossils, egg fossils, shell fossils , and foot print fossils.