​These are the tracks, burrows, or impressions of the animal and record their behaviour patterns and movements e.g. feeding, resting, moving. The animal that made them either died in situ (where the trace fossil is found) and was not preserved or moved on and did not die in situ. Examples include trackways, footprints, imprints, toothmarks, gastroliths (small stones swallowed by animals), coprolites (fossilised faeces), burrows, boreholes and nests. From trackways, palaeontologists can infer things such as the speed and length of the stride, how many legs the animal walked on and the bone structure of the foot.  

​These are impressions the dead organism made in the substrate when it fell to the ground or sea floor. The organism then decays, leaving behind only this impression.

​These form when the mould of the fossil has been in-filled by things such as minerals, and creates a solid mass which resembles a rock. Casts show the outward appearance of how the organism looked.

​These are the hard parts of the organism e.g. bones, teeth, claws, shells. Sometimes, the soft body tissue, such as muscles, tendons, organs and blood vessels, is also preserved.

These are the remains of the actual organism.

​These form when an organism is encased in a substance that does not allow decaying or minerals permeate and harden the organism. In petrified fossils, the organism within has not decayed or disintegrated.

​These are organisms that have been around for an incredibly long period of Earth's history and have changed relatively little during that time. Examples are jellyfish and the Lingulata brachiopod which has been around since the Cambrian (over 500 million years!).