Scientists exploring a forest on a remote Indonesian island say they have discovered several new species, including the world's smallest known wallaby, a long-nosed frog and a yellow-eyed gecko.
The scientists found the animals in the Foja Mountains on the island of New Guinea in late 2008 and released photographs and details of their discoveries on Monday.
The findings come ahead of the international day for biological diversity on May 22.
The species, which include several mammals, a reptile, an amphibian and a dozen insects, are thought to be entirely new to science, scientists from Conservation International and the National Geographic Society said.
The discoveries come as scientist warn of the growing threat of accelerating extinction of species as the planet warms and habitats are destroyed.
"While animals and plants are being wiped out across the globe at a pace never seen in millions of years, the discovery of these absolutely incredible forms of life is much needed positive news," Bruce Beehler, a scientist from Conservation International, told the Reuters news agency.
"Places like these represent a healthy future for all of us and show that it is not too late to stop the current species extinction crisis."
The forest where the animals has been largely unexplored by humans.
Scientists say one of the most interesting of the new species is the long-nosed frog, whose Pinocchio-like protuberance points upwards when the male calls, but downwards when he is less active.
The team also found other creatures including a tame woolly rat, a gecko with bent toes and yellow eyes, a new type of pigeon and a tiny wallaby that is thought to be the smallest member of the kangaroo family in the world.
Recent reports show that world governments failed to meet the targets agreed to in 2002 to reduce the rate of loss of biodiversity by 2010, which was declared by the United Nations to be the International Year of Biodiversity.
Negotiators from around the globe meet in Japan in October to discuss new targets to stem biodiversity loss for the next 40 years.