Tuesday, May 11, 2010

DEVONIAN

The Devonian Was the Age of Fish!

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By the Devonian the early Paleozoic oceans were closing, forming a "pre-Pangea". Freshwater fish were able to migrate from the southern hemisphere continents to North America and Europe. Forests grew for the first time in the equatorial regions of Artic Canada.

More Info about the Devonian World          

 By middle Paleozoic time, approximately 400 million years ago, the Iapetus Ocean had closed bringing Laurentia          
and Baltica crashing together.  This continental collision, preceded in many places by the obduction of marginal island arcs,          
 resulted in the formation of the Caledonide mountains in Scandinavia, northern Great Britain and Greenland, and the           
Northern Appalachian mountains along the eastern seaboard of North America.          
 It is also likely that by middle Paleozoic times, North China and South China had rifted away from the Indo-Australian           
margin of Gondwana, and were headed northwards across the Paleo-Tethys Ocean. Throughout the Early and Middle           
Paleozoic, the expansive Panthalassic Ocean covered much of the northern hemisphere.  Surrounding this ocean was a          
 subduction zone, much like the modern"ring-of-fire" that surrounds the Pacific Ocean.    
 The Devonian was the Age of Fishes. Fish evolved jaws early in the Devonian and became the top predators by the     
end of this Period.    
 Plants took over the land and became so abundant that the first coal deposits formed in the tropical swamps that    
covered much of the Canadian Arctic Islands, northern Greenland, and Scandinavia.  

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