About 150 scientists scoured Denniston Plateau at the weekend in the dead of night, and during a storm, in the hope of finding new species that could help derail plans by Perth-based Bathurst Resources to mine the plateau.
They believe they have discovered several previously unknown species of moth, cicada, and possibly even a snail and a gecko.
The proposed Escarpment Mine would be capable of producing up to two million tonnes of coal a year, creating 250 jobs. It was granted resource consent last year, although the commissioners said that was "not without some considerable reservations and anguish". It is now under appeal to the Environment Court.
Forest and Bird advocate Nicola Vallance said the scientists would now analyse the data before anything could be confirmed. However, the new finds would be part of their court case against the mine.
Some of the volunteers worked at night searching for nocturnal species on the 5900ha plateau, and were also out during the storm on Friday night.
Ms Vallance said the plateau was so high, cold and remote, that many predators did not live there.
"It's a natural sanctuary, almost a lost world. We don't need to spend millions of dollars on predator fencing there."
Denniston Plateau has 18 different eco systems, and the giant snail patrickensis is endemic there.
Bathurst says it is not proposing to open cut the entire plateau. It says the coal is in 'pockets' and in places it will be mined underground.