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Family: Polygyridae
Common name: Pinhole Threetooth
Discovery: Hubricht, 1952
Identification
Width: 9-14 mm
Height: 6-9 mm
Whorls: 5+
Triodopsis messana’s depressed shell is typically a reddish-brown color. The later whorls are lined with radial striae. The outer lip of the aperture contains a rounded tooth, bent slightly into the aperture, and the parietal tooth is long and curved. A small tubercle can be seen on the basal lip. Its teeth are similar to those of T. fallax but less robust. The shell’s umbilicus is narrower than in T. hopetonensis.
Ecology
This species prefers open terrain, and is rarely found in woods. It occurs in clearings and meadows, along roads and railroad tracks, and occasionally in abandoned urban habitats (Hubricht 1985).
Taxonomy
T. messana has also been known as Triodopsis fallax messana. Triodopsis messana is a close relative of Triodopsis fallax, and its taxonomy as a unique species – not simply a hybrid or ecotype of T. fallax – is not clearly established (Emberton, 1988).
Distribution
This animal as currently recognized is only known from Virginia and the Carolinas, and in Virginia only from Suffolk County (Hubricht, 1985).
Conservation
NatureServe Global Rank: G4
NatureServe State Rank: S1S3
Virginia’s wildlife action plan: Tier IV
