Fossils February 28, 2011 Chapter 8.1, p. 318-324

Key Terms and Goals Key terms: fossil, mold, cast, petrified fossil, carbon film, trace fossil, paleontologist Students will know what a fossil is and how fossils can be help us learn about Earth’s geologic and biological history.

What is a fossil? Fossils are the preserved remains of living things. EXAMPLE: A fish dies and becomes a fossil.

How does a fossil form? Fossils form when a living thing dies and is buried by dirt or sand. The dirt or sand slowly hardens into rock and preserves the shape of the once living thing. Usually only bones, shells, teeth, seeds and woody stems become fossils because the rest of the organism quickly decays or is eaten by animals.

There are many types of fossils. Above is a mold. Below is petrified wood. Above is a cast.

Trace fossil (below). Carbon film (above). Amber (below).

Why are fossils important? Fossils provide evidence about the history of life and past environments on Earth. Fossils also show how organisms have changed over time. EXAMPLE: If paleontologists find fish fossils in a desert, they know that were was once water in the area.

Fossil Lab Do the following on your paper: Draw each fossil. What is this a fossil of? What might this fossil tell us about Earth’s history? For fossil #9, draw a picture of this animal when it was alive in its habitat.