Abstract
Tree-kangaroos (genus Dendrolagus) are a morphologically distinctive genus of specialized, arboreal macropodids confined to the wet forests of New Guinea and northeast Australia. A distinct Goodfellow’s group, containing up to four species, has long been recognized. Resolving the relationships of taxa within the group has been hampered by limited samples of most taxa. Here we supplement published genetic data from high quality tissue samples with molecular data generated from museum specimens to improve taxon and geographic coverage. This includes specimens of the previously unsampled D. g. goodfellowi, the holotype and paratype of D. deltae, and additional specimens of D. matschiei, D. spadix and D. g. buergersi. DNA sequence data were generated from three mitochondrial loci. Phylogenetic analysis improved the resolution of relationships within the Goodfellow’s group, with the morphologically similar D. g. goodfellowi and D. g. buergersi being recovered as sister taxa, while D. pulcherrimus was the sister to the closely related, but morphologically and ecologically distinct, D. spadix and D. matschiei. Despite being sister to D. g. buergersi, D. g. goodfellowi was highly divergent. However, the two are morphologically very similar and we recommend retaining the taxonomic status quo (recognizing them as two subspecies of a single species) until improved sampling and a more thorough analysis is possible. The problematic D. deltae was confirmed as a junior synonym of D. matschiei.