This chart breaks down four main fossil types — Trace, Mold, Cast, and True Form Fossils — using characteristics, formation, and examples:

🐾 Trace Fossils

• Definition: Evidence of organism activity (not the organism itself).

• Examples: Footprints, burrows, coprolites (fossilized dung).

• Key Facts:

  • Show soft tissue movement.

  • Help scientists study behavior, like walking or burrowing.

  • Can be replicated using plaster.

🕳️ Mold Fossils

• Definition: An impression left in rock after the organism decays.

• Key Facts:

  • Shows shape but not the organism.

  • Often formed in mud that hardens.

  • The actual organism is gone.

🪨 Cast Fossils

• Definition: Created when a mold is filled in, forming a 3D replica.

• Key Facts:

  • Shows positive space (the organism’s shape).

  • Made from minerals or sediment filling a mold.

  • Helps visualize the full form of the organism.

🧊 True Form Fossils

• Definition: The actual preserved parts of the organism.

• Examples: Insects in amber, frozen mammoths, bones, shells.

• Key Facts:

  • Shows the organism itself.

  • Soft tissues may remain intact.

  • Offer the most direct evidence of ancient life.

Each type of fossil reveals different insights — from physical form to behavior.