Fossils are the preserved remains, impressions, or traces of any once-living thing from a past geological age. They can include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood, and more. Fossils can be categorized into two major types: body fossils and trace fossils.

• Body fossils: These are the preserved remains of plants and animals, including fossil bones, teeth, shells, and petrified wood.
• Trace fossils: These are the evidence left by organisms in sediment, such as footprints, burrows, and plant roots.

Fossils provide important evidence for evolution and the adaptation of plants and animals to their environments. They can teach us where life and humans came from, show us how the Earth and our environment have changed through geological time, and how continents, now widely separated, were once connected. Fossil evidence provides a record of how creatures evolved and how this process can be represented by a ‘tree of life’, showing that all species are related to each other.

Fossils are typically found in sedimentary rocks and occasionally some fine-grained, low-grade metamorphic rocks. They are formed when organic matter in remains is gradually replaced with minerals, ultimately turning the remains to ‘rock’ . There are different types of fossils because remains can be preserved in a variety of ways. Some examples of natural geological formations that may be mistaken for fossils are concretions and dendrites.

Fossil collection as performed by paleontologists, geologists, and other scientists typically involves a rigorous excavation and documentation process. Unearthing the specimen from the rock is often painstaking work that includes labeling each part of the specimen and cataloging the location of each part within the rock. Those fossils slated for removal from the rock are slowly and carefully excavated using techniques designed to prevent or minimize damage to the specimen. Such fossils often become part of museum or university collections. Many other fossils, however, are collected by hobbyists and commercial entities. Often such specimens are not carefully documented or excavated, resulting in a loss of data from the site and risking potential damage to the specimen.