Fossils

A fossil is the preserved remains of a living organism, either plant or animal, in the Earth’s crust. Of all the organisms that live and have lived on Earth, a very small percentage become fossilized and a part of the fossil record. The soft tissues of organisms break down easily. Sometimes the hard parts of organisms are also destroyed by forces such as weathering and erosion. When fossils are found, they are almost always a harder part of the organism. Bones, teeth, and claws are all examples of harder parts found on organisms. It is these parts that are likely to survive for millions of years.

Formation of Fossils

There are a variety of ways that a fossil can form. Of the three types of rock, fossils are likely to be discovered in sedimentary rock. The conditions that form sedimentary rocks are favorable to fossilize a once living organism. However, the organism must have a quick burial to avoid weathering, erosion, scavengers, or bacterial decay. View this interactivity to learn the many ways that fossils form. Click the player button to begin.

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Fossil Clues

The Earth’s rocks are like its personal diary.  Details of the events that occurred during deposition and formation are recorded within each bed of rock.  In order to discover what happened millions, even billions of years ago, geologists rely on the clues held in rocks and the information they can discover from fossils. In this activity, learn how the many clues regarding Earth’s past are derived from the study of fossils. Click the player button to begin.

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Fossils Review

Now that you have investigated fossils, practice what you have learned. In this non-graded interactivity, drag the descriptions on the right and drop them next to the terms on the left. Click the player button to begin.