Britannica Educational Publishing - The Paleozoic Era. Diversification of Plant and Animal Life

THE PALEOZOIC ERA
DIVERSIFICATION OF
PLANT AND ANIMAL LIFE

THE GEOLOGIC HISTORY OF EARTH

EDITED BY JOHN P. RAFFERTY, ASSOCIATE EDITOR, LIFE AND EARTH SCIENCES

Published in 2011 by Britannica Educational Publishing
(a trademark of Encyclopdia Britannica, Inc.)
in association with Rosen Educational Services, LLC
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First Edition

Britannica Educational Publishing
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John P. Rafferty: Associate Editor, Life and Earth Sciences

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Introduction by Catherine Vanderhoof

Library of Congress Cataloging-in-Publication Data

The Paleozoic era: diversification of plant and animal life / edited by John P. Rafferty.
p. cm.(The geologic history of Earth)
In association with Britannica Educational Publishing, Rosen Educational Services.
Includes bibliographical references and index.
ISBN 978-1-61530-196-6 (eBook)
1. Geology, StratigraphicPaleozoic. 2. PaleoecologyPaleozoic. I. Rafferty, John P.
QE654.P2413 2010
561.112dc22

2009051123

On the cover: Plants such as ferns (above) and ancient creatures such as the trilobite (below) were common during the Paleozoic era. SSPL via Getty Images (above); Sinclair Stammers/Photolibrary/Getty Images (below and pages )

On page : Fallen pine trees in Emerald Lake, reflecting the Burgess Shale, British Columbia, Canada. Shutterstock.com

T he Paleozoic Era is probably less familiar and perhaps less dramatic than the age of the dinosaurs that would dominate the Mesozoic Era that followed. However, the Paleozoic Era contained one of the most intense increases in biodiversity in Earths history, the Cambrian explosion and the subsequent Ordovician radiation. It also contained the largest extinction event the world has ever known, the Permian extinction, which wiped out more than 90 percent of marine species and roughly 70 percent of species on land. It was also a time of great geological changes as landmasses migrated and collided, eventually creating the supercontinent called Pangea. Sea levels rose, drowning whole continents, fell, and rose again. Some of Earths oldest mountain ranges, such as the Appalachians and the Urals, were formed during the Paleozoic. Life moved from the oceans to dry land and insects took wing for the first time. Many evolutionary advances took place, which set the stage for life as we know it today. Some of these advances include the development of plants with seeds, shelled eggs, and organisms capable of breathing air. So in geologic history the Paleozoic Era was pretty dramatic after all. In the pages that follow, all of these developments, as well as the clues that scientists have used to decipher the history of Earths changes, will be explored.