Devonian Period

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The mass extinction of Marine-life in the Silurian Period opened up endless possibilities and potential for terrestrial life in the next Geologic time period, The Devonian Period. The Devonian Period served as an introduction to the expansion of the first amphibians, sharks, and some of the first plants with roots, leaves, and stomata. Despite such significant advances, the Devonian Period is best known for its diversity and abundance of underwater life. Not only did fish with cartilage begin to appear during this period, but also fish with bony skeletons and it are these primitive predecessors of fish that encompass a majority of modern fish.

Numerous noteworthy changes in the world's geography took place during the Devonian Period. During this period, the world's land was split between two supercontinents, Gondwana and Euramerica (Rice). These vast landmasses sat relatively close to each other in a single hemisphere, while a vast uninterrupted ocean covered the remainder of the globe. These two supercontinents were completely surrounded by numerous subduction zones. The subduction zone between Gondwana and Euramerica set a major collision in motion that would later bring the two continents together to form the massive single continent, Pangaea (Rice).

In addition to ample global shifts, many important regional activities occurred. The continents of North America and Europe collided, resulting in massive granite formations as well as the formation of the Appalachian Mountains located on the eastern side of the North American continent. Extensive reef building produced some of the world's largest reef complexes (“More Info about the Devonian World”). These reefs were built in the equatorial seas between the two preexisting cont...

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Rice, Stanley A. "Devonian." Science Online. Facts On File, Inc. Web. 25 Apr. 2012. http://www.fofweb.com

Kusky, Timothy. "Devonian." Science Online. Facts On File, Inc. Web. 25 Apr. 2012. http://www.fofweb.com

University of California Museum of Paleonto (Lead Author);C Michael Hogan (Topic Editor) "Devonian". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth January 22, 2010; Last revised Date November 17, 2011; Retrieved April 25, 2012 http://www.eoearth.org/article/Devonian

Sallan, Lauren Cole, and Michael I. Coates. "End-Devonian Extinction and a Bottleneck in the Early Evolution of Modern Jawed Vertebrates." Diss. Cambridge University, 2010. 17 May 2010. Web. 25 Apr. 2012. http://www.pnas.org

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