Three new vertebrate species, isolated for millions of years, have been discovered in a James Cook University-National Geographic expedition to Cape York Peninsula in north-east Australia.

The expedition yielded species that were previously unknown to mankind - a prickly-looking leaf-tail gecko, which measures 20 centimeters, a golden-coloured skink and a boulder-dwelling frog.

Conrad Hoskin from the University and a National Geographic film crew were dropped by helicopter onto the rugged inhospitable Cape Melville mountain range on Cape York.

"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. 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," Hoskin said in an official statement.

The researchers claim that these species might have been living in isolation in the rocky, mountainous environment for millions of years.

The highlight of the expedition was the discovery of the 'primitive-looking' Cape Melville leaf-tailed Gecko.

Described as a Gondwanan relic from an ancient era when rainforests were more widespread in Australia, gecko's intriguing features are its huge eyes and long and slender body and limbs -probably adaptive features to sustain in the dimly lit boulder fields. Plus, the vertebrate's bizarre skin patterns act as an excellent camouflage to trap any passing insects or spiders.

"That this gecko was hidden away in a small patch of rainforest on top of Cape Melville is truly remarkable," Patrick Couper, Curator of Reptiles and Frogs at the Queensland Museum, said in the statement. "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."

Skinks, the second discovery of the expedition, are members of the Scincidae family (the largest lizard family). The species has smaller limbs than other lizard's species and lacks a well-defined neck.

The third vertebrate, the boulder-dwelling frog, has been dubbed the Blotched Boulder-frog. It spends most of the dry season in the moist, cooler areas deep within the boulder field.

"You might wonder how a frog's tadpoles can live in a 'hollow' boulder-field with no water sitting around." Hoskin said. "The answer is that the eggs are laid in moist rock cracks and the tadpoles develop within the eggs, guarded by the male, until fully-formed froglets hatch out. As for the gecko, its eyes are very large - once again an adaptation for life in the dimly lit boulder-piles."

"This frog lives most of its life deep in the boulder-fields where it is dark, cool and moist, and only comes to the surface when it rains."

Currently, many of the world's lizard and amphibian species are facing threat of extinction due to a combination of habitat destruction, global warming, and fungal disease.

 "All the animals from Cape Melville are incredible just for their ability to persist for millions of years in the same area and not go extinct. It's just mind-blowing," Hoskin told Planet Save.