A vast continental area believed to have existed in the northern hemisphere and to have resulted from the break-up of Pangaea in Mesozoic times. It comprised the present North America, Greenland, Europe, and most of Asia north of the Himalayas.
A vast continental area believed to have existed in the northern hemisphere and to have resulted from the breakup of Pangaea in Mesozoic times. It comprised the present North America, Greenland, Europe, and most of Asia north of the Himalayas.