Ch 9 View From Earth’s Past Time Scales Fossils Terms Time Periods Random 100 200 300 400 500

The mass extinction at the end of this period led to abundant new life forms in the Mesozoic and Cenozoic Eras Answer

Permian Period Home

How many billion of years ago did the Earth form? Answer

4.6 billion Home

The era of time that began 65 million years ago Answer

Cenozoic Era Home

How many eons is geologic time divided into? Answer

4 eons Home

What is the first period of the Mesozoic Era? Answer

Triassic Period Home

The impact hypothesis states that an _____ crashed into Earth, making the dinosaurs extinct. Answer

Asteroid Home

What are the most common Precambrian fossils? Answer

Cyanobacteria Home

Relative ages of sedimentary rock all around the world created the _____ column Answer

Geologic column Home

True or False: the mass extinction at the end of the Permian Period led to abundant new life forms Answer

True Home

What natural forces can destroy fossils? Answer

Tectonic Activity: Volcanic activity, folding, faulting, and erosion . Home

What is the longest unit of geoligic time? Answer

Eon Home

What is the gradual development of organisms from preexisting organisms? Answer

Evolution Home

The ordered arrangement of rocks in a column Answer

Geologic column Home

An episode in which a large number of species became extinct Answer

Mass extinction Home

What does “Ma” mean? Answer

Millions of years Home

What period is known as the “Age of Fishes” Answer

Devonian Period Home

What divisions of geologic time makes up about 88% of Earth’s history? Answer

Precambrian Home

This era is known as the “age of mammals” Answer

Cenozoic Era Home

At the end of this period, dinosaurs became extinct. Answer

Cretaceous period Home

This era is divided into 3 periods:, Triassic, Jurassic and Cretaceous Answer

Mesozoic Era Home

In a geologic column, where are the oldest rocks? Answer

The bottom Home

Geologic era that ended about 251 million years ago Answer

Paleozoic Era Home

What is a geologic period usually names for? Answer

The place where characteristic fossils were first discovered Home

True or False: Radiometric dating can help determine the absolute age of rocks Answer

True Home

Dinosaurs were most abundant in this period Answer

Jurassic Period Home