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Definitions
Geologic Time Scale
Grab Bag
Divisions of Geologic Time
Fossils
100
_________ is the death of every member of a species
What is extinction?
100

Name the time in Earth's history: Clue #1: 4,600 mya to 541 million years ago Clue #2: no Oxygen in air

What is Precambrian?

100
True/False: Humans have existed for most of Earth’s history.
False.
100
The largest division of geologic time are ______________.
What are eons?
100
How did scientists know what dinosaurs looked like?
They examine fossil evidence.
200
___________ is the extinction of many species at the same time
What is mass extinction?
200
Name the time in Earth's history: Clue #1: 251 million years ago Clue #2: Age of Reptiles
What is the Mesozoic era?
200

How is the geologic time scale of Earth’s history divided?

What are Eras, Periods, Epochs, or major events.

200
Eons are divided into __________.
What are eras?
200
The earliest fossils are of …
One-celled organisms
300
The age of an event or object in relation to other events or objects is called ______________
What is Relative age
300

Name the period when Pangaea began to break up

What is the Jurassic Period?

300
True/False: Throughout Earth’s history, the number and type of life forms has remained fairly constant.
False.
300
Eras are divided into __________.
What are periods?
300
A fossil is an object that contains traces, remains, or evidence of ..
Living things from long ago
400
The oldest sections are shown on the __________, and the recent sections would be on the ________.
What is bottom/top?
400

Name the time in Earth's history: Clue #1: Humans first appeared

What is the age of mammals, Cenozoic Era, Neogene period,  or Miocene Epoch.

400
Mass extinction can happen when ..
Gradual changes in the climate or ocean currents OR huge events like a meteor falls from the sky and makes giant hole in the ground, kicking up dirt and soil into the air that blocks out the sun for a long time until plants die. Then when a lot of plants die, animals that eat plants have no food, and they die too.
400
Periods are divided into ____________.
What are epochs?
400

Fossils that are abundant, lived for a short period of time, are easily recognizable, and widely distributed are called

What is the index fossil?

500

Preserved remains of plant and animals from the remote past are called

What are fossils?

500

The first trace of life on earth can be traced back to..

3.8 - 4 billion years ago (4,000 mya)

500
Give an example of creatures that were victims of a mass extinction
What are dinosaurs?
500

There are _____ Eras in Earth’s history.

What is four?

500
The soft parts of an organism often decay very quickly. The result is that many fossils..
Only preserve traces of the hard parts of the organism.