Gondwana As Gondwana began to rotate clockwise, Australia shifted south to more temperate latitudes. An ice cap initially covered most of southern Africa and South America but began to spread to eventually cover most of the supercontinent, save for northern-most Africa-South America and eastern Australia. Giant lycopod and horsetail forests continued to evolve in tropical Laurasia together with a diversified assemblage of true insects. In Gondwana, in contrast, ice and, in Australia, volcanism decimated the Devonian flora to a low-diversity seed fern flora – the pteridophytes were increasingly replaced by the gymnosperms which were to dominate until the Mid-Cretaceous. Australia, however,
Geology of Scotland remained in desert conditions, with higher ground in the Highlands and Southern Uplands providing sediment to the surrounding basins via flash floods. This is the origin of sandstone outcrops near Dumfries, Elgin and the Isle of Arran. Towards the close of this period sea levels began to rise and climatic conditions became less arid. As the Jurassic (201–145 Ma) started, Pangaea began to break up into two continents, Gondwana and Laurasia, marking the beginning of the separation of Scotland and North America. Sea levels rose, as Britain and Ireland drifted on the Eurasian Plate to between 30° and 40° north.