The Ice Age – The Cryogenian Period (850-630 million years ago)
Even though there wasn’t ice everywhere when the ice age occurred, Australia and the rest of the continent were majorly affected by ice glaciers (known as bulldozers). Due to the environment being very cold and the outskirts of the glaciers turning into artic deserts, glaciers preserved the fossils of various plants and animals. Based on this fossil evidence, it is proven that animals such as bears and antelopes roamed the land and adapted to the cold temperatures during this chilly time.
Rainforests (135-45 millions years ago)
As Australia broke free from Antarctica and slowly drifted northwards, the ice began
to melt and a substantial amount of rainfall penetrated the continent and rainforests were covering much of the continent. Plants such as shrubs were able to mix with the largely popular conifers at this time and adapt to the cool, moist climate. Geographical evidence shows that the temperature of surrounding oceans changed, resulting in altered climatic patterns and lower rainfall over the land.
Desert/Dry Land (15 million years ago)
Australia’s northward journey came to an abrupt when the edge collided with the Asian continental plate and the widespread rainforests began to die, as they were unable to survive the increasingly dry temperatures. Australia’s movement towards the equator, and a worldwide change in atmospheric and oceanic circulation patterns caused Australia to evidently dry out. The moist conditions that once ruled the land were no more and fossil preservation was just about impossible.