Index Fossils (8th Grade)

Determine the most Important - INDEX FOSSILS

On each slide, decide what is the most important information.

Properties of an Index Fossil

Index fossils are used to determine the relative ages of rocks.The best index fossils are of organisms that existed for a very brief time but are found over a large (widespread) area of Earth.  In a sequence of rock layers, an index fossil would not be found in very many layers vertically but would be found widespread horizontally from one place to another.

Properties of an Index Fossil

It is likely that a long time from now, humans will be an excellent index fossil.  Humans have existed for a relatively short time, yet our remains and signs of our existence can be found worldwide.

Fill in the information as you watch the video
https://www.youtube.com/watch?v=PN3xpDs_Wz0

Multiple Select

Choose ALL of the criteria a fossil must meet in order to be labeled an index fossil.

• existed for a brief time

• found in large (widespread) area of the Earth

• abundant amount

• are found in many, many layers vertically in a set of rock layers

​represents the rock layers and fossils found at four widely separated ares of exposed rock layers. Use it to answer the following questions.

The following diagram...

Multiple Choice

Which fossil is the best index fossil?

Multiple Choice

Based on the fossils above, in what type of environment/habitat were the rock layers formed?

• rainforest

• desert

• ocean

• swamp

Multiple Choice

Question is at the bottom of the picture to the left. Click to enlarge the picture.

• approx. 10 million years old

• less than one million years old

• more than 50 million years old

• approx. 50 million years old