Intro

Objective 1/23/13

Identify various types of fossils.

Which of the following pictures shows a fossil? How do you know?

FOSSILS

Fossils

What is a fossil? The remains or physical evidence of an organism preserved by geologic processes

Fossils

How do fossils form?

Usually, an organism is buried in a substance that helps to protect and preserve its remains.

Found only in sedimentary rocks.

Fossils

Environmental Change

Example

Fossils can be good indicators that an area has undergone environmental change

Marine fossils found in freshwater lakes

Marine fossils found on mountaintops

Desert fossils found in ice caps

Picture…

Fossils

Where can you find fossils?

Rocks Amber Petrifaction Tar Ice

Fossils

Rock An animal or plant gets quickly buried in sediments, forming new rock and a fossil

Fossils

Amber Insects (most common) get trapped in tree sap which hardens over time

Fossils

Petrifaction Process in which minerals replace an organism’s tissues

Fossils

Tar (Asphalt) Tar-pits trap animals like tree sap traps insects

Fossils

Ice Ice preserves organisms very well, even their skin and organs!

Warning!

Gross picture up ahead!

Fossils

Other types… Trace fossils Molds Casts

Fossils

Trace Fossils Preserved EVIDENCE of an organism, NOT the actual organism! Tracks Burrows Coprolite

Fossils

Molds A cavity where something was buried

Fossils

Cast Forms when sediments fill in a mold

Fossils

Summary: What are fossils? What are some different ways fossils can

be created or preserved?

Objective 1/20/2013

Outro

Identify various types of fossils.

Why do you think one animal or plant becomes fossilized, but millions of others do not?