Advances from empirical studies in phylogeography, systematics and species delimitation highlight the importance of integrative approaches for quantifying taxonomic diversity. Genomic data have greatly improved our
ability to discern both systematic diversity and evolutionary history. Here we combine analyses of mitochondrial
DNA sequences, thousands of genome-wide SNPs and linear and geometric morphometrics on Antaresia, a clade
of four currently recognised dwarf pythons from Australia and New Guinea (Antaresia childreni, A. stimsoni, A.
maculosa and A. perthensis). Our integrative analyses of phylogenetics, population structure, species delimitation,
historical demography and morphometrics revealed that the true evolutionary diversity is not well reflected in
the current appraisal of the diversity of the group. We find that Antaresia childreni and A. stimsoni comprise a
widespread network of populations connected by gene flow and without evidence of species-level divergence
among them. However, A. maculosa shows considerable genetic structuring which leads us to recognise two
subspecies in northeastern Australia and a new species in Torres Strait and New Guinea. These two contrasting
cases of over and under estimation of diversity, respectively, illustrate the power of thorough integrative approaches into understanding evolution of biodiversity. Furthermore, our analyses of historical demographic
patterns highlight the importance of the Kimberley, Pilbara and Cape York as origins of biodiversity in Australia. 