Neuquenraptor Hemisphere. South America however, during the Mesozoic became part of Gondwana. The find of "Neuquenraptor" provides some possible indication of the degree of isolation between the Northern and Southern hemispheres. The supercontinent Pangaea started to break up in the Early Jurassic, leading to the separation around 160 Ma of Laurasia in the north and Gondwana in the south. Gondwana itself was soon fragmented into West Gondwana (i.e., Africa and South America) and East Gondwana (i.e., Antarctica and Australia plus India and Madagascar). West Gondwana broke apart during the Cretaceous, as Africa and South America separated between 132 and 90 Ma.
Pangaea that took place between North America and Africa produced multiple failed rifts. One rift resulted in a new ocean, the North Atlantic Ocean. The Atlantic Ocean did not open uniformly; rifting began in the north-central Atlantic. The South Atlantic did not open until the Cretaceous when Laurasia started to rotate clockwise and moved northward with North America to the north, and Eurasia to the south. The clockwise motion of Laurasia led much later to the closing of the Tethys Ocean and the widening of the "Sinus Borealis", which later became the Arctic Ocean. Meanwhile, on the other side of Africa