The largest delta plain in Earth's history formed along the northern coast of the supercontinent Pangea in the late Triassic. Its size out-scales modern counterparts by an order of magnitude, and approximates 1 percent of the total land area of the modern world. And although contenders are found in the rock record, no ancient counterpart exceeds the extent of the Triassic delta plain mapped in the subsurface Barents Sea either.