Earth History Part 2

Identify the Era:
called the "Age of Mammals"

• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic

The geologic time scale is a record of___

• the thickness of sedimentary rock layers
• the rate of fossil formation
• the life forms and geologic evnts in Earth's history
• the time since the evolution of dinosaurs

Identify the Era:
where dinosaurs thrived

• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic

Identify the Era:
Amphibians first developed in this era.

• Precambrian
• Paleozoic
• Mesozoic
• Cenozoic

The fossil record shows that life on Earth has changed over time.  For example, paleontologists have found that older rocks contain fossils of

• organisms that are more complex than those alive today
• both simple and complex organisms
• only organisms that are alive today
• organisms that are simpler than those alive today

How do most fossils form?

• Living things die and their remains are covered by sediment
• The hard parts of an organism dry out in the air
• The soft parts of an organism change to stone
• Freezing preserves the remains of an organism

What do most scientists think caused the mass extinction of dinosaurs and other organisms at the end of the Cretaceous period?

• an object from space struck Earth
• volcanic eruptions covered large areas with lava
• an ice age covered most of Earth with ice
• The dinosaurs ate too many other organisms and then starved

The Paleozoic, Mesozoic, and Cenozoic are divisions in the geologic time scale called ____

• centuries
• layers
• periods
• eras

The presence of the same ________ on several continents supports the idea of continental drift.

• rocks
• fossils
• both fossils and rocks
• neither fossils nor rocks

A lack of evidence for continental drift prevented many scientists from believing a single supercontinent called _________ existed.

• Glossopteris
• Pangaea
• Gondwanaland
• Mesosaurus