How Do Fossils Form?

Source Institution: Smithsonian National Museum of Natural History

Source Exhibit: David H. Koch Hall of Fossils - Deep Time

Source Url: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list

Source Kind: interpretive_topic_or_panel

Use: research inspiration only; SAGE will write original interpretation

Dossier Status: scientifically_enriched_concept_room_01

Plain Language Explanation: Fossilization is not one process. Bones, teeth, shells, wood, leaves, footprints and even activity traces can enter the geological record in different ways. Rapid burial often protects remains from scavenging and weathering. Minerals may fill pores or replace original material, shells may leave molds and casts, leaves may form compressions, and rare conditions can preserve organisms in amber, ice or other unusual settings.

Evidence: Body fossils preserve parts or impressions of organisms.; Trace fossils record activity such as tracks, trails and burrows.; Mineralogy and microscopic structure can reveal whether original biological material remains or has been replaced.

Examples From Collection: Quercus sp. petrified wood; Pinophyta indet. mineralized wood; Chelichnus bucklandi trackway; Hymenaea protera amber; Pentamerus oblongus internal molds; Pecopteris strongii leaf

Common Misconception: A fossil does not have to be a bone, and it does not have to preserve the original material of an organism.

What Scientists Still Debate: The fossil record is incomplete and strongly biased by environment, anatomy and preservation. Researchers must distinguish true biological patterns from patterns caused by what happened to organisms after death.

Sources: https://www.nps.gov/subjects/fossils/how-fossils-form.htm; https://www.nps.gov/subjects/fossils/what-is-a-fossil.htm

Enrichment Method: SAGE original interpretive concept; source title retained; evidence separated from reconstruction and open questions