An expedition into a hidden rainforest in Queensland, Australia has yielded some interesting mix of new creature species. The three vertebrate species were a bizarre looking leaf-tailed gecko, a gold-coloured skink which is a type of lizard, and a brown-spotted, yellow boulder-dwelling frog.

Dr Conrad Hoskin and Dr Tim Laman, from James Cook University and Harvard University, respectively, made the discovery on the rugged Cape Melville mountain range on Cape York Peninsula, a rainforest perched on boulders in a remote part of Queensland.

"We're talking about animals that are ancient - they would have been around in the rainforest of Gondwana... rainforest that's been there for all time," Dr Hoskin said.

"The top of Cape Melville is a lost world. Finding these new species up there is the discovery of a lifetime - I'm still amazed and buzzing from it," Dr Hoskin, a tropical biologist from the Queensland-based university, added. "Finding three new, obviously distinct vertebrates would be surprising enough in somewhere poorly explored like New Guinea, let alone in Australia, a country we think we've explored pretty well."

Taken to the site aboard a helicopter, Dr Hoskin said this is the first time that the hot, dry, boulder-strewn rainforest on the plateau top is being examined. Scientists previously examined only the base Cape Melville mountains.

"Finding three new, obviously distinct vertebrates would be surprising enough in somewhere poorly explored like New Guinea, let alone in Australia, a country we think we've explored pretty well," Dr Hoskin said in a statement from the university.

Of the three vertebrate species, scientists considered the Cape Melville Leaf-Tailed Gecko the highlight of the expedition.

"The Cape Melville Leaf-Tailed Gecko is the strangest new species to come across my desk in 26 years working as a professional herpetologist. I doubt that another new reptile of this size and distinctiveness will be found in a hurry, if ever again, in Australia," Patrick Couper from the Queensland Museum was quoted by CNN.

Dr Hoskin named it Saltuarius eximius, meaning exceptional or exquisite because of its distinct appearance.

The Cape Melville Shade Skink was named Saproscincus saltus while the Blotched Boulder Frog was Cophixalus petrophilus. Saltus meant leaping while Cophixalus petrophilus connoted rock-loving.

"These species are restricted to the upland rainforest and boulder fields of Cape Melville. They've been isolated there for millennia, evolving into distinct species in their unique rocky environment," Dr Hoskin said.

With the discovery of the three new vertebrate species, Dr Hoskin strongly believed there is more than meets the eye in Cape Melville for future expeditions.

"The top of Cape Melville is a lost world. Finding these new species up there is the discovery of a life time - I'm still amazed and buzzing from it," said Dr Hoskin.