Red Data Okinawa Revised: Okinawa Prefecture's Threatened Wildlife 3rd Edition (Animals).
Distribution overview: Endemic to Nohara-dake, Miyako Island.
Population trends: Since its description, no live shells have been found, and it was considered an extinct species, but in February 2014, a live shell was discovered for the first time. It is not known to exist anywhere other than Mt. Nohara.