was a supercontinent
formed in the Middle Palaeozoic
by the collision of two Cambrian
continents Laurentia (Mostly the present North America
) and Baltica (Present Western Eurasia). Laurussia was relatively short lived. It collided with the Southern Supercontinent Gondwana
in the Permian
to form a single continent Pangea
comprising most of the Earth's continental crust.