the tiny (1.7 x 1.2 mm) snail was discovered by frank climo in the 1970s, but was considered to be just one form of another subterranean "hadopyrgus" snail found in the nelson area. in 2001 martin haase and christina mosimann collected more specimens from maitai cave by washing and sieving gravel, and using both morphological and genetic evidence realised these belonged to a distinct species. they scientifically described and named it "hadopyrgus ngataana" in 2008; the name they chose, "ngataana," comes from the māori words "ngata" (snail or slug) and "ana" (cave).