Australias land has a diferent thing is made up of territories .
they like a flat terrain like a platue
As old as history itself, at least a few million years.
It is now known what North America look like 100 million years from now.
60 million years ago Canada was a mass of ice.
What is the terrain of mesopotamia
nuthinq . a star ?
Three millennia (the plural of millennium) is 3000 years. Each millennium is 1000 years. (A millennium is not one million years, despite sounding like "million".)
Geologic time is very long, so a million or more years is the best choice.
The terrain was gentle swelling hills
The Ichthyosaurs, predatory sea reptiles, were rather like modern dolphins. They existed from the Early Triassic Period (250 million years ago) till the Middle Cretaceous Period (100 million years ago).
Ice age!