Hello!
The name for continents in one landmass surrounded by gigantic ocean is Pangaea.
This name is originated from the Greek words Pan ("all") and Gaia ("Earth"). It describes the supercontinent that would have existed in the Cenozoic and Mesozoic periods by the joining of all continents that we know them today.
The gigantic ocean that surrounded it is called Panthalassa, from Greek Pan ("all") and thálassa ("sea").
Have a nice day!
