Laurasia was one of two supercontinents which, in turn, formed part of the supercontinent Pangea, about 335 to 175 million years ago; being the supercontinent of the north, Laurasia was formed by the primitive North America and Eurasia, taking the northern part of the modern continents as their lands. At that time, several mountain ranges arose from the collision of the contientes when they united in one, and caused, when they separated again, that North America, Europe and Asia, had similar geological formations, and similar primitive fauna and flora. Currently, the found fossils of the Mesozoic era are of the same type on both continents.
