Riversleigh in the Miocene wasn’t anything like the dry plains that we see today. Think the Daintree region of Far North Queensland, where the rainforest meets the sea, and you get an idea what the landscape was like 25 million years ago. At Riversleigh, you can even see some fossilised wave action.
As for the fauna, it was rather different. Aside from the big bird, there were big snakes, wombats, kangaroos, and crocodiles. The long-nosed animal is my old friend, the palorchestes, related to the koala.