How difficult is it to become a fossil? Objective By the end of the lesson, students will understand how difficult it is to become a fossil, the steps to becoming a fossil, and how preservation bias plays a role. Background Fossils are found in rocks all over the world and help teach scientists about paleo ecosystems. Plants, animals, insects, leaves, seeds and even dung can become a fossil, given adequate conditions. There are many ways in which fossils form, but it is not always easy to become a fossil. Where the organism lives and what its body parts are made of are strong factors that can Duration: 60 Minutes.