Valvata tricarinata

Valvata tricarinata, common name the three-ridge valvata or threeridge valvata, is a species of small freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Valvatidae, the valve snails.

Distribution
This species occurs in North America.

Shell description
There is great variation in the degree of carination of the shell.

Paleontology
Valvata tricarinata is abundant in nearly all lacustrine and fluviatile deposits in North America of the Pleistocene period. The fossil shells are more variable than the Recent ones. Eight forms or subspecies were described.