Geologic Time

Question 1

Name the time periods

Answer 1

Precambrian
Paleozoic
Mesozoic
Cenozoic

Question 2

Explain Precambrian

Answer 2

4600 million years ago
First multi-called organisms
Precambrian shields are formed
First single-felled organisms

Question 3

Explain Paleozoic

Answer 3

570 million years ago 
Periods when large parts of North America are covers by shallow seas
-large swamps 
-Appalachians formed 
-age of amphibians and fish 
-first insects
-first plants and animals appear on land

Question 4

Explain Mesozoic

Answer 4

245 million years ago

• shallow seas in the interior of North America at various times
• formation of Rocky Mountains begins
• innuitian mountains formed
• first bird and mammals
• age of reptiles
• first flowering plants

Question 5

Explain Cenozoic

Answer 5

66 million years ago

• formation of the Rocky Mountains completed
• continents take on their present shape
• humans begin to develop
• modern forms of life evolve
• age of mammals
• ice sheets cover much of North America