or Pangaea
Hypothetical protocontinent proposed by continental drift .
Pangea (from Greek: pangaia , "all earth") supposedly covered about half the Earth and was completely surrounded by a world ocean called Panthalassa. Late in the Triassic Period (248–206 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 Ocean.