1. Fossils Fossil: Any evidence of prehistoric life forms or environments Often found in sedimentary rock layers (sandstone or shale)

2. Shale deposits in the Grand Canyon

3. Fossil-bearing sandstone and shale strata near Blewett Pass, Washington

5. Badlands, South Dakota

6. Paleontologists excavating a prehistoric watering hole in Badlands

7. Types of Fossils: 1.Petrified Remains hard, rocklike remains usually bones or wood

8. 2. Molds and Casts Mold: organism decays but leaves behind an imprint in sediments Cast: Other sediments fill in the imprint and harden

11. 3. Carbonaceous Films Heat and pressure push down on the organism leaving behind carbon residue

13. 4. Original Remains Actual preserved parts of organisms Preserved in: –amber (crystallized sap) –frozen ground –tar pits

14. 5. Trace Fossils Fossilized tracks Worm “tracks” Ripple marks from water waves

16. Index Fossils

17. Species that existed for a short period of time Were abundant Were widespread geographically Used to determine the ages of rock layers

18. Index Fossil Correlation

19. Fossil Lab (in notebook) Make detailed drawings of five different kinds of fossils from the specimens in class Drawings must be at least 12 cm long (you may need to use a microscope for some specimens) Label each drawing Tell what type of fossil each is (cast, petrified, etc.) For at least three of your specimens, give the time when the organism existed on Earth