It was not until the 1980s and 1990s that significant numbers of dinosaurs began to be excavated from Australia. These principally came from excavations at Dinosaur Cove in Victoria and Lightning Ridge in New South Wales. Most of these fossils are from dinosaurs that are new to science and are still being studied. In the dinosaur stakes, Australia was dealt a poor hand for a number of reasons. Firstly, when dinosaurs were roamed the earth, there were few places where the right kinds of rocks were being deposited.
Dinosaurs tend to be preserved in sediments laid down by rivers and lakes.
During the reign of the dinosaurs most of Australia was covered by a shallow sea. Secondly, since the age of dinosaurs, there has not been much mountain-building in Australia. If land is lifted up and eroded back, it's possible to see into the rock beds and find the fossils inside. This has happened in a number of the worlds famous dinosaur deposits elsewhere in the world but not here in Australia. Lastly, compared to many other places in the world, Australia has very few palaeontologists looking for fossils and a very large area to cover.