Fossils are traces of things that happened long ago. Plants and animals can become fossils. Fossils are not the original, only a copy. In Plants the most famous example of fossilized plants is petrified wood; Ferns, tree leaves, and other plants have been found, too. In animal, the most famous fossils are of dinosaurs. There are also fossils of sea creatures and mammals. Sometimes many fossils are found in one place because of a flood, earthquake, or other disaster