Land Snails

Photo(s): Aperture view of Triodopsis pendula © Bill Frank. Views of another T. pendula specimen © Dan Dourson.

Click photo(s) to enlarge.

Triodopsis pendula (Hubricht, 1952)

Family: Polygyridae
Common name: Hanging Rock Threetooth

Identification
Width: 9.5-13.8 mm
Height: 5.0-7.2 mm
Whorls: 5+

The shell of Triodopsis pendula is a depressed heliciform and covered with radial striae, as are many threetooth snails. The large final whorl is twice the width of the preceding one. A tooth on the outer lip is wide and rounded. The basal tooth is blunt, while the high parietal tooth is curved and connects to the columella. In and around the funnel-shaped umbilicus and behind the reflected lip are strong papillae, seen under magnification. The shell is smaller and more depressed than the shell of Triodopsis vulgata, and the outer lip tooth is smaller and not as inflected.

Ecology
Triodopsis pendula prefers oak woods and can be found in leaf litter and near logs (Hubricht, 1985).

Distribution
This rare animal is only known from the foothills east of the Appalachian Mountains, in North Carolina and, possibly, abutting Grayson County, Virginia. This Virginia county appears in range maps by Hubricht (1985), though no museum specimens for this location have been encountered. The species is listed as imperiled in Virginia.

NatureServe Global Rank: G3
NatureServe State Rank: S1S3
Virginia’s wildlife action plan: Tier II

 

Meegan Winslow, Ken Hotopp 11/2012