Do Now

• How do scientist know that different kinds of plants and animals lived in Earth’s past?

• What is a fossil?

Objective

I will be able to describe how different fossils are formed.

What is a fossil?

• Are the preserved remains or traces of living things that provide evidence of how life and Earth’s surface has changed over time

Fossil Flow Chart

How are fossils formed?

• Most fossils form when living things die and are buried by sediments.

• The sediments slowly harden into rock and preserve the shapes of the organisms.

• The remains or traces of an organism must be protected from decay

http://www.youtube.com/watch?v=KxDQwBZj9o8&feature=related

Petrified fossils

• Water rich in dissolved minerals seeped into spaces in the plant cells and then evaporated leaving hardened minerals behind.

Molds and Casts

• Mold– A hollow area in sediment in the shape of the

organism– Forms when the hard part of the organism is

buried in sediment• Casts– Later water carrying minerals and sediment may

seep into the empty space of a mold--resulting in a cast

– Is a copy of the shape of an organism

Carbon fossil

• All living things contain carbon• When sediment buries an organism some of

the material turns to gas.• The gas escapes from the sediment leaving a

thin film of carbon • Can preserve the delicate parts of plant leaves

and insects.

Trace fossils

• Provide evidence of the activities of organisms• Provide clues about an animals size and

behaviors• Ex. Fossilized footprints

Preserved remains

• Preserve remains with little or no change to the organism

• Ex. Trapped in tar, preserved in amber, freezing

A Fossil’s StoryDirections: On a sheet of paper, write a story about fossilization from the point-of-view of the organism.

The following items should be included:1. Type of organism: give a detailed description2. How the organism died3. Where did they die: the surrounding environment4. How were they fossilized: include the process they went

through.5. What type of fossil did they turn into 6. Who found them and what did that person think of the

fossil

Objective

I will be able to describe how different fossils are formed.

Exit Ticket

• Make a list of the different types of fossils.• What is the difference between a mold fossil

and a cast fossil?• What is the difference between a petrified

fossil and a preserved remains?

Homework

ACT Prep

• John is faster than Pete. Dave is faster than Harvey. Dave is slower than Pete. Which man is fastest and which is slowest?

• If Bob and Fred are both taller than Tom, while Hal is taller than Bob but shorter than Fred, which man is tallest and which is second tallest?