In the current crisis of global biodiversity loss, the discovery of new species is a welcome addition. But the recent finding that the mountain brushtail possum, an arboreal marsupial mammal of Australian wet forests, is actually made up of two species also poses new conservation challenges. The new species is proposed in an article in the latest Australian Journal of Zoology (Volume 50, Issue 4), authored by Earthwatch-supported biologist Dr. David Lindenmayer (Australian National University) and colleagues. “Geographic dimorphism in the Mountain Brushtail Possum (Trichosurus caninus) – the case for a new species,” describes how the northern and southern populations of the mountain brushtail possum are both morphologically and genetically distinct.