Geologic Time Scale & Index Fossils CERs 1/19/2022 - Jessica Soria | Laabri

1

Prompt: These three hills used to be one hill in the past before they separated. Based on the law of superposition, which fossil is the oldest?

Coral

Ammonite

Fern

Trilobite

1

Prompt: Look at the hill on the right. Based on the law of superposition, which fossil is the youngest?

Trilobite

Ammonite

Fern

Coral

3

Prompt: An index fossil is a fossil that only shows up in one rock layer (a single rock layer has the same color). Study the three hills and identify the three index fossils.

Carefully read through the scenario, chart, and prompt before answering the question.

Prompt: Examine the Hermit Shale strata (265 million years ago) and the Toroweap Formation (255 million years ago). Based on the rock strata and the fossils found in each strata, how did the environment and life in the Grand Canyon change over that period of time?

1

Choose the best claim.

Based on the fossils found in the rock strata, the environment transformed from a terrestrial (land) environment to an aquatic environment with marine organisms.

Based on the fossils found in the rock strata, the environment transformed from an aquatic environment to an terrestrial (land) environment with land organisms.

2

Write your evidence. (For full credit, you should cite at least 2 pieces of evidence from the chart.)

2

Write your reasoning. (For full credit, you should restate your claim, cite at least 2 pieces of evidence, and use the Law of Superposition to explain how your evidence proves your claim.)