Chapter 9 Concept Review Scary Dinosaurs

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

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

A theory that a meteorite caused the extinction of dinosaurs is called the _________________ _____________. Impact hypothesis

"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 ____________ 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)