Resolution of the Petaurus genus in Australia and New Guinea
Petaurid gliders are iconic Australian species that provide ecosystem services and are vulnerable to habitat modification and fire. However, these small and charismatic gliding marsupials have thus far been almost completely neglected by researchers in the north. Our work over the past 2 years has revealed that we have much to learn about the systematics of the entire Petaurus genus, with evidence for the existence of new species in different regions of Australia and PNG.
Lambalk or the savanna glider (currently classified as a sugar glider; Petaurus breviceps ariel and the only glider currently recognised in NT and WA) is one such animal that we know remarkably little about, despite its broad distribution. Preliminary taxonomic work revealed that it is likely not a sugar glider, but has closer affiliations to the squirrel (P. norfolcensis) and mahogany gliders (P. gracilis), both of which occur many hundreds of km away on the eastern seaboard.
More recent work has ascertained that specimens of the NT and WA subspecies P. b. ariel form two distinct evolutionary lineages, based on mtDNA, and are most closely related to P. norfolcensis and P. gracilis rather than P. breviceps. Genetic analyses also revealed the existence of several samples from both the NT and Cape York that are closely affiliated with P. gracilis, but are well outside its current distribution. To the south, concurrent investigations have revealed evidence of two distinct lineages of (what was) P. breviceps occurring throughout inland and coastal Eastern Australia. The geographical distribution of the two evolutionary lineages does not correspond with the current distribution of the morphological subspecies, warranting further detailed investigation of these phylogenies.
Samples from New Guinea have also shown considerable mtDNA sequence and morphological divergence among populations of Petaurus gliders, and there is evidence for the existence of new species from several of the islands adjacent to Papua New Guinea.
We are using targeted marsupial exon capture to contribute to a complete resolution of species in the Petaurus genus and resolve the phylogenetic relationships among Australian and New Guinean taxa, and hence their biogeographic histories.