5.9D Fossils

5.9D Fossils

By Susan Barron

​Fossils are the remains or traces of plants and animals that lived long ago.

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​What are fossils?

Most fossils form in sedimentary rock.​

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Fossils Show Changes in Life

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-Older rock layers contain organisms different from those found in younger rock layers

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-Life forms have changed over millions of years.​ For example, giant sea reptiles came before giant land dinosaurs. Mammals arrived last!

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Clues to the Past Environments (Dinosaur Valley)

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-Fossilized tracks show that there were herds traveling together.

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​-Fossils of trees and shells indicated that a shallow sea once covered the area

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-Mari​ne fossils, such as plankton, were found on top of a mountain, indicating that it was once under water

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​-Ferns were found in layers of shale that indicated the area was once a swamp

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Multiple Choice

The picture shows rock layers next to a road. Layer 3 most likely formed in which of these environments?

• Desert

• Forest

• Ocean

• Tundra

Multiple Choice

What is the correct order of the rock layers from oldest to youngest?

• A, B, C, D, E, F

• F, E, C, D, B, A

• F, E, D, C, B, A

• A, B, C, E, D, F

Multiple Choice

The diagram represents the layers found inside a rocky cliff. The rock layers contain fossils. Which of the following layers of rock is most likely the youngest?

• The layer containing trilobites

• The layer containing aphibians

• The layer containing mammals

• The layer containing fishes

Multiple Choice

Which layer of rock is the oldest?

• A

• B

• C

• D

Multiple Choice

Fossil trees were discovered in a sedimentary rock layer. In the rock layer below are fossils of clams, similar to clams found on the shores of the Gulf of Mexico. Based on this evidence, we could conclude that the area where the fossils were discovered had what environments in the past?

• Sea followed by Forest

• Forest and later than a mountain

• Forest followed by Beach

• Tundra followed by forest

Multiple Choice

What type of environment existed when this fern leaf was created?

• Desert

• Ocean

• Forest

• Tundra

Multiple Choice

This table gives information on different fossils. According to the information in the table, finding which fossil in a region would lead to the conclusion that the area was, long ago, covered in trees?

• Snail Shell

• Scorpion

• Dragonfly

• Millipede

Multiple Choice

This rock contains fossils of water plants and shells. What does this tell us about the rock?

• The rock contains many living things

• The rock was once in the middle of the forest

• The rock is heavier than most rocks

• The rock was once at the bottom of the sea