Phylogenetic analysis reveals additional diversity within the Dendrolagus dorianus (Marsupialia: Macropodidae) group from New Guinea

The tree-kangaroos (genus Dendrolagus) are specialized arboreal macropodids now confined to the rainforests of New Guinea and northeastern Queensland, Australia. Within New Guinean Dendrolagus, a distinct Doria’s group has been recognized since 1936. However, establishing the species limits and inter-relationships within the group has long been hampered by limited sampling. In this study we supplement published genetic data from high quality tissue samples with molecular data generated from museum specimens to improve taxon sampling and geographic coverage within the Doria’s group to enhance our understanding of their evolutionary history. This included the addition of the previously unsampled D. mayri (holotype and only known specimen) and additional specimens of D. dorianus and D. notatus. DNA sequence data were generated from three mitochondrial loci and six distinct Doria’s group lineages were identified: D. dorianus, D. notatus, D. stellarum, D. scottae, D. cf. stellarum and D. mayri. Phylogenetic analysis improved the resolution of relationships within the Doria’s group, with D. dorianus being recovered as the sister to all other taxa. Surprisingly, D. mayri and D. cf. stellarum were monophyletic and formed a sister group to the three other species (D. notatus, D. stellarum and D. scottae). This indicates that the molecular affinities of D. cf. stellarum, from the Sudirman Range, Central Cordillera, lie with D. mayri (isolated on the Wondiwoi Peninsula to the west) rather than true D. stellarum from the Star Mountains further east along the Central Cordillera. The molecular divergence between D. cf. stellarum and D. mayri (3.8% sequence divergence) is less than that reported between other Dendrolagus species (> 4.7%). Therefore, D. cf. stellarum is best regarded as a differentiated population of D. mayri and should be referred to as D. cf. mayri pending further studies. This finding means that D. stellarum (sensu stricto) does not occur on the Maokop (Central Cordillera mountains east of the Baliem Valley, West Papua).