Banded dune snail

The banded dune snail or Morro shoulderband (Helminthoglypta walkeriana) is a species of endangered air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the subfamily Helminthoglyptinae.

Taxonomy
At the time the species was divided into two subtaxa (subspecies or varieties): H. w. walkeriana and H. w. morroensis. The latter was thought to be extinct but was rediscovered. In 2004, it was elevated to species status as Helminthoglypta morroensis and it inherited the endangered status it had when it was part of Helminthoglypta walkeriana.

Both snails together were known as the banded dune snail. Today H. walkeriana proper is the Morro shoulderband, and H. morroensis is the Chorro shoulderband.

Distribution and habitat
It is endemic to the area around the cities of Morro Bay and Los Osos in the central coast in San Luis Obispo County and Santa Barbara County, in California. The total area of occurrence has been calculated to be as low as 40 km2.

Diet and ecology
The snails eat decaying plants and are eaten by birds, reptiles and mammals. Within the narrow distribution in coastal dune and scrub communities in western San Luis Obispo County, they only come out in wet weather. They seal themselves inside of their shells for months at a time when a drought is in effect, only to reemerge when rains return.

Conservation
This snail was placed on the United States' Endangered Species List in 1994. the IUCN Red List considers the snail Critically Endangered, and NatureServe considers it Imperiled.

The USFWS recommends that the Morro shoulderband be downlisted to threatened status and the Chorro shoulderband be delisted.