Pangea

Hypothetical protocontinent proposed by Alfred Wegener in 1912 as part of his theory of continental drift. Pangea (from Greek: pangaia, “all earth”) supposedly covered about half the Earth and was completely surrounded by a world ocean called Panthalassa. Early in the Jurassic Period (approximately 200 million to 146 million years ago), Pangea began to break apart. Its segments, Laurasia (composed of all the present-day northern continents) and Gondwana (the present-day southern continents) gradually receded, resulting in the formation of the Atlantic and Indian oceans.