In 2009, more than 200 yet unknown species were discovered in poorly-known areas of Papua New Guinea (see Conservation International: “Incredible array of new species found in remote Papua New Guinea”; 6 Oct 10, link below).
New Guinea is considered a biodiversity hotspot, having close to 10% of the world’s vertebrates on 1% of the total landmass. The island’s fauna is also very different from what is found in surrounding islands. Tree kangaroos and birds of paradise are just two among many groups (see WWF: “New Guinea Animals and Plants”, link below).
New Guinea’s fauna now faces growing threats, from logging, mining, agricultural plantations and over-use of species (see WWF as above, also Mongabay: "Indonesia to target New Guinea for agricultural expansion", 22 Feb 10, and “World's rarest tree kangaroo gets help from those who once hunted it”, 17 Aug 09, link below).