Sci. 3-4 Looking at Fossils Page 68-72

A. Fossil- any naturally preserved evidence of life.

1) Fossils in rock- usually the hard parts are preserved

2) Mineral replacement- minerals filled in the pores of an organisms tissue

3) Fossils in Amber- insects falls in sap and it hardens into amber.

4) Mummification- organism dies in a dry place and dry out fast so the tissues do not decay

5) Frozen fossils- freezes in a glacier

6) Fossils in tar- preserved in a tar pit

B. Trace Fossils- any naturally preserved evidence of an animal’s activity 1)track- foot print 2) burrows- shelter made by animals in the ground 3) coprolites- preserved feces or dung

4) Mold and casts- mold is cavity in the ground or rock where an organism was buried. A cast is an object created when sediment fills the mold and becomes rock.

C.Fossils can tell scientists the following: 1)How earth’s environment has changed over time 2) how plants and animals have changed over time 3) how rocks have changed positions.

D.Index Fossil- are fossils of organisms that lived during a relatively short, well-defined time span. 1) These can help date rocks.