<P> Since the Eocene the northward movement of the Australian Plate has resulted in an arc - continent collision with the Philippine and Caroline plates and the uplift of the New Guinea Highlands . From the Oligocene to the late Miocene, the climate in Australia, dominated by warm and humid rainforests before this collision, began to alternate between open forest and rainforest before the continent became the arid or semiarid landscape it is today . </P> <P> The adjective "Gondwanan" is in common use in biogeography when referring to patterns of distribution of living organisms, typically when the organisms are restricted to two or more of the now - discontinuous regions that were once part of Gondwana, including the Antarctic flora . For example, the plant family Proteaceae, known from all continent in the Southern Hemisphere, has a "Gondwanan distribution" and is often described as an archaic, or relict, lineage . The distributions in Proteaceae is, nevertheless, the result of both Gondwanan rafting and later oceanic dispersal . </P> <P> During the Silurian Gondwana extended from the Equator (Australia) to the South Pole (North Africa and South America) whilst Laurasia was located on the Equator opposite to Australia . A short - lived Late Ordovician glaciation was followed by a Silurian Hot House period . The End - Ordovician extinction, which resulted in 27% of marine invertebrate families and 57% of genera going extinct, occurred during this shift from Ice House to Hot House . </P> <P> By the end of the Ordovician Cooksonia, a slender, ground - covering plant, became the first vascular plant to establish itself on land . This first colonisation occurred exclusively around the Equator on landmasses then limited to Laurasia and, in Gondwana, to Australia . In the Late Silurian two distinctive linages, zosterophylls and rhyniophytes, had colonised the tropics . The former evolved into the lycopods, that were to dominate the Gondwanan vegetation over a long period, whilst the latter evolved into horsetails and gymnosperms . Most of Gondwana was located far from the Equator during this period and remained a lifeless and barren landscape . </P>

At 150 ma what is the relationship of africa and south america