LAURASIA

hypothetical continental mass in the Northern Hemisphere that included North America, Europe, and Asia (except peninsular India). Its existence was proposed by Alexander Du Toit, a South African geologist, in Our Wandering Continents (1937), a reformulation of the continental drift (q.v.) theory advanced by the German meteorologist Alfred Wegener. Whereas Wegener had postulated a single supercontinent, Pangaea (q.v.), Du Toit theorized that there were two such great landmasses: Laurasia in the north and Gondwanaland (q.v.) in the south, separated by an oceanic area called Tethys. Laurasia is thought to have fragmented into the present continents largely during the Mesozoic Era (from approximately 245 million to 66.4 million years ago).