Historical transitions across the marine-freshwater interface are regarded as key triggers for adaptive radiation of many aquatic clades. Using the Australian terapontid fish family as a model system, we combine molecular genetic techniques with rapidly developing comparative phylogenetic approaches to appraise the macro-ecological evolution of the family. These combined approaches reveal several significant features of the terapontid freshwater adaptive radiation following invasion of freshwaters by marine ancestors.  A range of macro-evolutionary processes such as: significantly higher rates of lineage and phenotypic evolution in freshwater clades compared to marine counterparts;  significant dietary ecomorphological correlations; and convergent evolution between ecologically similar marine and freshwater species are all revealed by comparative processes.  The integration of ecological data with molecular phylogenies (a field in its relative infancy in Australia) has great potential to provide similar insights into the evolutionary history of a range of additional fish families. With its unique biogeographic history, Australian freshwaters may provide a novel testing ground for many of the contemporary theories of evolutionary biology and adaptive radiation.