Pyrgulopsis pachyta (F. G. Thompson, 1977) The armored marstonia, scientific name Marstonia pachyta, also known as Pyrgulopsis pachyta, is a species of freshwater snail, an aquatic gastropod mollusc in the family Hydrobiidae.

This species is endemic to Alabama, in the United States,[1] where it is found in only two creeks, both in Limestone County.

[3] Its two locations are separated by the man-made Wheeler Lake.

[2] It is threatened by habitat loss.

This Hydrobiidae-related article is a stub.