Name:
Period:
Chapter 9 Test Review
1. The geologic time scale is
2. The gradual development of new organism from preexisting organisms is referred to
as__________________________________.
3. Precambrian Period ended about _________________________ year ago.
4. The first flowering plant occurred during the _______________________________ period.
5. Large areas of exposed Precambrian rocks are called _______________________________.
6. Which climate change allowed mammals to become the predominant life form?
7. Scientists are able to determine the ages of most rock layers in geologic column by
using_________________________________.
8. Geologic Periods can be divided into _____________________.
9. What are the Earth’s 4 geological Eras?
10. Which is the longest Era?
11. The Age of the Reptiles is the name given to which Era?
12. Stromatolites were present during which Era?
13. The Age of the mammals is the name commonly given to which Era?
14. The Age of the Fishes is in which Era?
15. Give 2 hypotheses that explain the mass the extinction of dinosaurs.
Use the Time Scale to answer the questions below:
Period
Million years ago
Quaternary
0.0115
Tertiary
1.8
Cretaceous
146
Jurassic
200
Triassic
251
Permian
299
Carboniferous
Devonian
318
416
Silurian
Ordovician
Cambrian
444
542
542
16. Which period did humans first appear?
17. Which period did amphibians first appear?
18. What period did modern birds first appear?
19. When were dinosaurs the dominant life form on Earth?
20. How many years ago did mammals first appear?
21. Which Era were dinosaurs present?
Characteristics from geologic
and fossil evidence
The last glacial period ends;
complex human societies
develop
Humans appear, age of
mammals begins, first primates
appear
Plants and modern birds
appear; mass extinction marks
the end of the Era
Dinosaurs are the dominant life
form; primitive birds and flying
reptiles appear
Dinosaurs appear; ammonites
are common and mammals
appear
Pangaea comes together; mass
extinctions mark end of era
Reptiles appear
Age of fishes begins,
amphibians appear
Land plants and animals appear
Modern oxygen rich state
Shelled marine invertebrates
appear, first vertebrates appear