The Moapa pebblesnail also known as the Muddy Valley turban snail, scientific name Pyrgulopsis avernalis, is a species of small freshwater snail with an operculum, an aquatic gastropod mollusk in the family Hydrobiidae.

This species is endemic to the Moapa Valley, Nevada, United States[2] and the common name refers to the Moapa River in Nevada.

Pyrgulopsis avernalis is a small snail that has a height of 2.4–4.3 millimetres (0.094–0.169 in) and ovate conical shell.

Its differentiated from other Pyrgulopsis in that its penial filament has a small lobe and large filament with the penial ornament consisting of a small terminal gland, a gland along the outer edge of the penial lobe and a ventral gland.

[2] When originally described in 1935, it was assigned to the genus Fluminicola.