4-7 The Earth's History

During the Mesozoic Era the earth's climate varied from very dry to moist.  The temperature cooled off during this era as well.

Dinosaurs were the main animal during this period, however  they became extinct at the end of the Mesozoic Era after ruling the earth for more than 100 million years.

Tiny small mammals and the first birds also arose during this era.  Palm trees and cone-bearing plants were plentiful.  It was during the end of this era that flowering plants developed.

The Cenozoic Era was hot and moist.  Swamps covered large areas of land at this time.  Forests and flowering plants continued to grow and grasslands developed as well.  Mountain ranges began to form during the middle of this era.

Mammals were widespread at this time.  These primitive mammals however disappeared during the middle of the era, and were replaced by modern animals.  Fossil records show that humans also appeared at this time.

Late in the Cenozoic Era, the temperatures began to cool.  Large areas of land were covered with glaciers.  Large wooly mammals called mammoths roamed the earth during this period.  As the earth warmed up and the glaciers melted the mammoths became extinct, just as the dinosaurs of the Mesozoic Era had.

We continue to live in the Cenozoic Era.  Changes continue to occur and develop.  The changes however occur so slowly they are not easy to identify.

Directions: Answer the questions about the Mesozoic and Cenozoic Eras.

were the main large animals during the Mesozoic Era.

During which era did grasslands appear and mountains form?

Mesozoic
Cenozoic

During which era did birds first inhabit the earth?

Mesozoic
Cenozoic

During which era did glaciers cover the earth?

Mesozoic
Cenozoic

Dinosaurs became extinct after more than 100 years of ruling the earth.

Dinosaurs became extinct during which era?

Mesozoic
Cenozoic

Large wooly animals called roamed the earth during the Cenozoic Era.

These large wooly animals became extinct during which era?

Mesozoic
Cenozoic

During which era did mammals become widespread?

Mesozoic
Cenozoic

During which era did flowering plants develop?

Mesozoic
Cenozoic

Which era do we presently live in?

Mesozoic
Cenozoic

Which of the following statements is true about the Cenozoic Era?

No changes are presently occurring during this era.
Changes continue to occur and develop

Put the eras in order.  Use 1 for the oldest, 2, 3, and 4.

Cenozoic

Paleozoic

Mesozoic

Precambrian