How do they know that Australia joined to Antarctica?
We can match the same rock types from Australia to Antarctica, we can look at the way the two continents fit together if you cut them out like pieces of a jigsaw, and we can match fossils on each side of the ocean to show that the same animals and plants lived there. We can also look at the age of the sea floor between Australia and Antarctica, and this shows us that at about 96 million years ago the two continents were together as one continent.
