Metatheria ago, followed by the evolution of deltatheroidian-like taxa in Asia and North America about 120-100 million years ago and then the Paleocene diversification of relatives to the crown marsupials in South America. This makes it a contemporary to some early eutherian species that have been found in the same area. The oldest metatherian fossils are found in present-day China. About 100 mya, the supercontinent Pangaea was in the process of splitting into the northern continent Laurasia and the southern continent Gondwana, with what would become China and Australia already separated by the Tethys Ocean. From there, metatherians spread westward into
Pangaea closing the Paleo-Tethys Ocean, but forming a new ocean, the Tethys Ocean, in its southern end. Most of the landmasses were all in one. By the Triassic Period, Pangaea rotated a little and the Cimmerian plate was still travelling across the shrinking Paleo-Tethys, until the Middle Jurassic. The Paleo-Tethys had closed from west to east, creating the Cimmerian Orogeny. Pangaea, which looked like a "C", with the new Tethys Ocean inside the "C", had rifted by the Middle Jurassic, and its deformation is explained below. Fossil evidence for Pangaea includes the presence of similar and identical species on continents that