The document provides a geologic time scale that needs to be completed using provided words and phrases. It divides geologic history into three main eras - Cenozoic, Paleozoic, and Mesozoic. The Cenozoic era saw the rise of modern mammals and birds as well as the most recent ice ages. During the Paleozoic era, trilobites were abundant while coal deposits formed during the Carboniferous period. The Mesozoic era was dominated by dinosaurs and saw the formation of Pangaea and its subsequent breakup.

1. GEOLOGIC TIME SCALE
Use these words and phrases to complete the Geologic Time Scale below.
Precambrian Superlarge mammals Pangaea forms/Appalachian Mts.
Cenozoic Trilobites abundant Pangaea breaks up
Paleozoic Age of Mammals/Birds Coal deposits form (First forest fossils)
Mesozoic First forests 9/10 of Earth’s history
Age of Dinosaurs Steep bluffs form along rivers (Mo.)
First abundant fish Rocky Mtns. form
Only simple marine life Most recent Ice Ages
Age of Reptiles Volcanic activity in S.E. Mo.
Humans Ozarks uplifted
Ancient Birds Ozarks eroded & covered repeatedly
Crinoids abundant in Mo. Last major uplift of Ozarks
Fault forms in S.E. Missouri.
Himalayan Mtns. form
HINT: Cenozoic is #1! Missouri covered by seas
Era Organic Changes Inorganic Changes
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© Copyright 2010. M. J. Krech. All rights reserved.