Unit 5 Review: The Fossil Record

Front

What is an index fossil?

Back

An index fossil is a fossil that is used to define and identify a particular time period in the geologic time scale. It is typically widespread, abundant, and existed for a relatively short duration.

Front

Why is fossil 3 not a good index fossil?

Back

It is in multiple layers of the same outcrop.

Front

What is the significance of the appearance or disappearance of life in geologic time?

Back

Scientists chose where units of geologic time began and ended based on the appearance or disappearance of life.

Front

What is the correct order of fossils from OLDEST to YOUNGEST: C, D, B, E, A?

Back

C, B, A, D, E.

Front

In which EON was the Cretaceous Period?

Back

Mesozoic.

Front

How old was the Proterozoic time Period?

Back

About 1 billion years.

Front

What is the geologic time scale?

Back

The geologic time scale is a system of chronological dating that relates geological strata to time, used by geologists and other Earth scientists to describe the timing and relationships of events in Earth's history.

Front

What defines the boundaries of the geologic time scale?

Back

The boundaries of the geologic time scale are defined by significant events in Earth's history, such as mass extinctions or major geological changes.

Front

What is the difference between the Paleozoic, Mesozoic, and Cenozoic eras?

Back

The Paleozoic era is characterized by the emergence of early life forms, the Mesozoic era is known as the age of reptiles, and the Cenozoic era is known as the age of mammals.

Front

What is a mass extinction event?

Back

A mass extinction event is a widespread and rapid decrease in the biodiversity on Earth, often resulting in the extinction of a large number of species.