When new species as large and colourful as tree kangaroos are discovered it is a rare event indeed.
Every year new species of mammals are being described, generally as a result of a currently known species being divided into several different species. It is less common for entirely new species to be discovered. These discoveries generally happen in relatively inaccessible parts of the world and are usually cryptic species (species which are difficult to find or distinguish from each other) such as small rodents or bats.
Tree kangaroos are attractive and elusive animals that inhabit the rainforests of north-east Queensland, New Guinea and adjacent islands. Between 1990 and 1995 two new species and two new subspecies of tree kangaroos from New Guinea were described by Dr Tim Flannery of the Australian Museum. The most recently described species, Dingiso Dendrolagus mbaiso, was brought to scientific attention by Dr Flannery in 1995. Dr Flannery had learned of the existence of this black and white tree kangaroo from the high altitude mossy forests of the Sudirman Range in West Papua several years earlier.
Currently, ten species are recognised in the group, nearly all of which are threatened by habitat loss or hunting. The type specimens (types are the original specimens on which the first description of a particular species or subspecies is based) of Dingiso and of three other recently described tree kangaroos are lodged in the Australian Museum's mammal collection. Soon the description of another new subspecies based on specimens in the collection will be added to the list.