Atlantica (Greek: Ατλαντικα; Atlantika) is an ancient continent that formed during the Proterozoic about 2,000 million years ago (two billion years ago, Ga) from various 2 Ga cratons located in what are now West Africa and eastern South America.[1] The name, introduced by John Rogers in 1996,[1] was chosen because the parts of the ancient continent are now located on opposite sides of the South Atlantic Ocean.[2]