What are Unknown Traces? Many trace fossils have unknown or unrecognized makers. They may record activities such as feeding, resting, crawling, walking, burrowing, or boring, but they have dimensions or patterns that make them difficult to assign to specific groups of organisms. Most have some pattern, repetition, or symmetry suggesting that they did not form through inorganic processes like wind or water current activity. Traces of unknown affinity have been found in rocks back to the Precambrian.
First known fossil occurrence: Precambrian.
Last known fossil occurrence: Quaternary. This group has living relatives.
Fossils through time:
Choose a time period to see what life was like: