North America, Devonian period. Computer artwork of the Devonian period stage (approximately 416 to 359 million years ago) of a sequence showing the formation of the North American continent. The continents are slowly moved over the surface of the Earth by currents in the fluid mantle below the crust. Over millions of years the continents moved into the positions they are in today. The present day position of the United States of America (USA) is shown outlined in white.
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