Earth History Timeline
Name/Date/Block: ________________________________________
Purpose: To create a model of the entire history of the Earth.
Introduction: We are going to make a scale model of Earth’s history. A scale model means that the timeline
accurately depicts different lengths of time. All of the times that we are going to deal with in this lab are in
millions of years ago (mya).
Procedure:
1. Our first step will be to place the four Eras on the timeline. Use the equation below to determine the
length each will be placed on the timeline.
To figure out the equation for the lengths needed the following proportion was used:
Length on Timeline
Length of whole timeline
=
age of event (mya)
age of earth (mya)
4600 mya = 600cm so…
Equation: Length on Timeline = ([age of event] ÷ 4600mya) x 600cm
Name of Era
Age of Event
(Today) End of Cenozoic
0 mya
Beginning of Cenozoic
65 mya
End of Mesozoic
65 mya
Beginning of Mesozoic
248 mya
End of Paleozoic
248 mya
Beginning of Paleozoic
543 mya
End of Precambrian
543 mya
Beginning of Precambrian
(Formation of Earth)
4600 mya
Length on Timeline (cm)
Color
Leave white
unless you
have time
2. You will need 6m of ticker tape paper. Tape it to the ground/desk so that it is all of the way open.
3. Label (in small letters) one end Formation of Earth / Beginning of Precambrian
4. Label the other end Today / End of Cenozoic
5. All of our times are in millions of years ago, so MAKE EVERY MEASUREMENT from the end that
says TODAY.
6. Label the events (HINT: Use one line, and label one side end of one Era, and beginning of another)
Example:
End of
Paleozoic
32cm
Begin
Mesozoic
End of
Mesozoic
8.5cm
Begin
Cenozoic
TODAY
End of
Cenozoic
0cm
7. VERY LIGHTLY COLOR each era, you will need to write there later so don’t make it too dark.
Leave the Precambrian white for now. If you have time go back and color it.
8. Each Era is broken up into Periods. Using the same equation as before, you need to label each of
the following Periods. Refer to pages 668-669 in your text.
Name of Period
Age each begins
Quaternary
2 mya
Neogene
24 mya
Paleogene
65 mya
Cretaceous
144 mya
Jurassic
206 mya
Triassic
248 mya
Permian
290 mya
Pennsylvanian
323 mya
Mississippian
354 mya
Devonian
417 mya
Silurian
443 mya
Ordovician
490 mya
Cambrian
543 mya
Length on Timeline (cm)
9. Next, get the Major Events handout from your teacher and determine which period each occurred.
Refer to pages 668-669 in your text. Cut then paste each in the appropriate period on your timeline.
Questions
1. What percent of the timeline falls in the Precambrian Era? (done for you)
[length of Precambrian era ÷ total age of Earth] 4057my ÷ 4600my (x 100) = 88%
2. What percent of the Earth’s history have humans been in existence?
3. What percent of the Earth’s history has there been abundant fossils?
4. The universe is about 15 billion years old (15000 million) what percentage of that time has the
Earth been in existence?
Major Events: Determine which period each occurred using your text as a reference. Cut out and
paste each in the appropriate period on your timeline. Find a way to make them fit!
Stromatolites, simple marine
organisms. No life.
Hominids develop.
Modern horse, camel, elephant
develop.
First reptiles
Trilobites
Giant dinosaurs. First birds.
Humans dominant. Domestic
animals develop.
Dinosaurs die out.
Graptolites
Crinoids
Mass extinction. Final uplift of
Appalachians.
First land plants
Reptiles thrive. Forests of
conifers and cycads.
Many new mammals appear.
Pygmy horse. First whales.
First amphibians