FOSSILSSECTION 29.1

PALEONTOLOGY

The study of life that existed in prehistoric times

FORMATION OF FOSSILS

5 types of fossils that scientists can observe:

1. Original Remains

2. Replaced Remains

3. Molds and Casts

4. Trace Fossils

5. Carbonaceous Films

1. ORIGINAL REMAINS

• An organism that is preserved in its entirety

• This type of fossil is very rare because of decay and decomposition

• Examples: mosquito in amber or a wooly mammoth in permafrost

2. REPLACED REMAINS

• Fossils that form very slowly as rock forming

• minerals replaces the organisms remains

• More common

• Examples: bones, teeth, and shells

3. MOLDS AND CASTS

• Mold – a hollow space left by a fossil after the fossil decays.

• Cast – minerals seep into the hollow space (mold) and make a copy of the fossil

• Examples: ferns, leaves, and fish

• Observe how fossils can form.

4. TRACE FOSSILS

• Indirect evidence of life that are preserved

• Examples: trails, footprints, tracks, burrows, bite marks and even fecal matter

5. CARBONACEOUS FILMS

• Thin carbon film that represents the silhouette of the organisms

• All that is left due to heat and pressure