Fossil Preservation and Sources of Bias in Fossil Fuels

Upon completing this activity, students should be able to:
- Define what fossil are
- Describe the process of fossil preservation
- Identify common modes of fossil preservation
- Describe potential sources of bias in the fossil record

- Screened, dry fossils from sieved, bulk-sediment samples (Figure 2; preferably from different beds at a single collecting locality and showing different modes of preservation and types of fossils).
- Field-collected fossils from the same location as the fossils from the bulk-sediment samples (Figures 3-5)
- Hand lenses
- PowerPoint presentation explaining common modes of preservation

- Start this exercise by having your students examine your bulk fossil samples from Jackson, MS. Have your students describe the fossils present and also have them try to figure out the environment where the fossils were deposited.
Ask your students a series of questions to get them thinking about why some organisms are preserved as fossils and
others are not. Do the fossils have any characteristics in common? What kinds of organisms lived in the inferred
depositional environment? Did all the organisms preserve or just certain kinds? Why are there no soft-bodied
organisms present?
- Now that your students are wondering about fossil preservation, begin the PowerPoint presentation on fossilization.
Ask your students: what is a fossil? Is there a difference between an organism that just recently died and a fossil
organism?

- http://gpc.edu/~pgore/geology/historical_lab/preservationlab.php
- http://dept.kent.edu/geology/ehlab/fossil_preserv/fossil_preserv.htm
- http://www.asn.csus.edu/geol/Deptwebpage/kusnick/Geology105/pres.html