Fossilization - The preservation of an ancient artifact. Index Fossil - A fossil that is useful for dating and correlating the strata in which it is found. Faunal Succession - The observation that a sedimentary rock strata contains fossilized flora and flauna. Tar - A dark, thick liquid distilled from wood or coal. Ice - Frozen water. Evolution - The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth. Variation - The difference between cells, individual organisms, or groups of organisms of any species.
