Our evidence for the existence of the different dinosaurs that lived in prehistoric Australia comes from fossilised animal remains and other records of life, such as fossilised footprints. Specific conditions are required for fossilisation to occur, which means that not all life-forms from the Mesozoic Era are preserved, but they are all we have to determine the types of animals that existed during this time. As Swinburne University palaeontologist Dr Stephen Poropat puts it, ‘we need the right rocks!’.