1. The Fossil Record 8-3
8-3

2. The Fossil Record Fossils – Traces or remains of plants or animals
Found in sedimentary rocks

4. Interpreting the Fossil Record
Clues to environmental changes
Marine fossils found in desert areas

5. Fossilization Most animals decompose or are eaten after death.
Usually just hard parts of organisms become fossils

6. Mummification Removal of internal organs Wrapping the body in cloth
Dry areas
Not much bacteria

7. Amber Hardened tree sap Insects become trapped and preserved
DNA - rare

8. Tar Seeps
Petroleum oozes to the surface
Animals become trapped

9. Freezing Organisms buried in frozen ice or soils do not decay
Bacteria cannot survive

10. Petrification
Mineral solutions replace original organic sediment with new material

11. Imprints
Carbonized imprints
Partially decays and leaves print behind

12. Molds and Casts Shells leave empty cavities or molds
Sand or mud fills in holes and form casts

13. Coprolites
Fossilized poop
Feeding habits

14. Gastroliths
Stones in dinosaurs digestive system

15. Types of Fossils Trace fossils – fossilized evidence of organisms
Footprints

16. Index Fossils Used to determine relative age of rocks
Fossils widespread, abundant, and distinct
Lived during a short time span

18. Index fossils – Absolute Age
Rock and fossil can be assumed to be close to the same age