Herpetologist Paul Oliver spotted Cyrtodactylus boreoclivus—which bears the characteristic curling toes of its genus—via the glow of his head lamp in 2008.

"The eye of the gecko reflects red, so you can see a gecko 20 to 30 meters [65 to 100 feet] away in a tree just by its eyeshine," said Oliver, of Australia's University of Adelaide.

"When we pulled this thing out of the tree, it was like, OK—straightaway I knew it was a new one," he said.

That's because the reptile has characteristics that set it apart from up to 23 related species that live on the island of New Guinea.

For one thing, the approximately 10-inch (25-centimeter) gecko is smaller than the many known gecko species on its home island of New Guinea—some of of which are among the world's largest and grow up to a foot (0.3 meter) long. (See a picture of a giant bent-toed gecko found in New Guinea.)

Also, the male C. boreoclivus sports a distinct pattern of pore distribution on its legs. Common to many gecko species, the pores exude a gooey substance, presumably containing a scent that conveys information to other geckos, Oliver said.

Oliver nearly missed that distinction, though, because males of the species proved especially elusive.

After three nights of searching and finding only females, he spotted a C. boreoclivus about 16 feet (5 meters) up a tree. Thinking fast, he found a long stick and tapped the trunk above the gecko. The lizard ran down and Oliver caught it—this time, it was a male.

More Geckos Waiting in the "Lost World?"

Oliver wasn't the first to discover the new gecko species, only the first to formally document it—as was made clear by a post-expedition trip to the Australian Museum in Sydney, where he found an old C. boreoclivus specimen marked as unidentified.

He suspects there are many more amphibian species waiting, unidentified, in the Foja Mountain forests. After all, scientists have explored the region only in the past few years, and only during short expeditions.