Chapter 9 Concept Review

Chapter 9 Concept Review
1. A large area of exposed Precambrian rocks is called
a _________________.
 shield
.2 A large cloud from which Earth formed is called a
 nebula
3. The gradual development of new organisms from
preexisting organisms is _________________.
 evolution
.5. An ordered arrangement of rock layers a
 Geologic column
4. A unit of geologic time that is longer than an age
but shorter than a period.
 epoch
6. An episode during which an enormous number of
species dies a _________________.
 Mass extinction
7. A fossil that is used to date rocks is an
 Index fossil
8. A unit of geologic time that is longer than an epoch
but shorter than an era is a _________________.
 period
9. A chart outlining the development Earth and life
on Earth is the _________________.
 Geologic time scale
10 A theory that a meteorite caused the extinction of
dinosaurs is called the _________________
Impact hypothesis
11. "206 Ma" means…
"206 million years ago.“ (d)
12. Coastlines took on their present shapes during the
Holocene Epoch (c)
13. The most common Cambrian invertebrates were
called ____________.
trilobites (d)
 14. Which of the following animal species evolved
during the Paleocene Epoch?
Primates (c)
15. Dividing Precambrian time into smaller time units
is difficult because…
few fossils exist in Precambrian rocks. (d)
 16. Coal deposits in the eastern United States are the
fossilized remains of forests and swamps from the
Carboniferous period (b)
 17. A mass extinction of marine invertebrates
occurred at the end of the Permian Period when …
shallow inland seas disappeared. (b)
18. The climate during the Mesozoic Era was generally
warm and humid (d)
19. The herbivore Apatosaurus belonged to the group
of dinosaurs called _____________.
saurischians (a)
 20. The division of geologic time that began with the
last ice age and includes the present is called the
Quaternary Period (c)

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