Tree kangaroo molecular systematics based on partial cytochrome b sequences: are Matschie's tree kangaroo (Dendrolagus matschiei) and Goodfellow's tree kangaroo (D. goodfellowi buergersi) sister taxa?
New Guinea tree kangaroos (Dendrolagus spp.) are unique arboreal macropodid marsupials mainly listed as critically endangered or endangered. The molecular systematics of Dendrolagus has not been fully resolved and is critical for the accurate identification of species and their evolutionary relationships. Matschie’s tree kangaroo (D. matschiei) and Goodfellow’s tree kangaroo (D. goodfellowi buergersi) share numerous morphological, physiological, and behavioural traits. We analysed the partial mitochondrial DNA cytochrome b gene for D. matschiei (n = 67), D. g. buergersi (n = 8), D. goodfellowi unidentified ssp. (n = 8), golden-mantled tree kangaroo (D. g. pulcherrimus; n = 1), and two additional New Guinea Dendrolagus taxa to determine whether D. matschiei and D. g. buergersi are sister taxa. D. matschiei and D. g. buergersi were not placed as sister taxa in our phylogenetic analyses; however, we were unable to analyse a known sample from a D. g. goodfellowi. We found initial genetic evidence that D. matschiei and the Lowland tree kangaroo (D. spadix) are sister taxa – they may have diverged after the formation of the Huon Peninsula of Papua New Guinea. Our results also support the elevation of D. g. pulcherrimus to a full species. An improved understanding of Dendrolagus molecular systematics will contribute substantially to their conservation.