Australian dinosaur palaeontology has recently experienced a surge of new discoveries, primarily focusing on the Winton and Griman Creek formations. This thesis contributes to the understanding of Australia’s dinosaur diversity by describing material from lesser-known sites and by exploring how incomplete and isolated material can be used to explore morphological variation and evolution. Notably, it includes the description of the second ankylosaur skull from Australia, identified as the oldest material referrable to cf. Kunbarrasaurus sp., and rediscovery of a diverse vertebrate locality near Surat, Queensland: including dinosaur, marine reptile, and shark fossils, with implications for the age correlation of the Griman Creek Formation. Despite the ever-growing knowledge of Australian dinosaur diversity, their ecology is vastly understudied. I provide the first comprehensive study of Australian sauropod ecology alongside the description of opalised sauropod teeth from New South Wales, and reveal sauropod tooth evolution on a global scale (incorporating Australian taxa for the first time) and explore how it relates to different ecological specialisations and environmental factors, using phylogenetic comparative methods and biomechanical analyses.