Environmental lobby Forest & Bird says a new species of cave weta found on the West Coast's Denniston Plateau is another piece of unique ecology which could be lost if an open-cast coal mine is built there.
The weta was discovered by a Massey University evolution researcher and has been informally named the Denniston white-faced weta.
The Australian-owned company Buller Coal has been granted resource consent to mine 200 hectares of the plateau.
Forest & Bird spokesperson Debs Martin said the new species of weta shows there is still more to learn about the ecological system on the plateau, and it's not yet known what would happen to it if an open-cast mine is built.