Dwarf Wedgemussel
Alasmidonta heterodon
Diagnostics 2
SHELL
- size: small. maximum 50 mm, most specimens under 40 mm
- thickness: thin
- shape: trapazoidal with pointed posterior end, rounded of straight posterior slope
- width: medium inflated
- surface: smooth
- beaks: slightly elevated. sculptures: 4 curved ridges angular towards posterior slope
- color/markings: periostracum yellowish brown to brown. greenish rays in young
- sexual dimorphism: female shells more inflated posteriorly
- pseudocardinal teeth: small, compressed
- lateral teeth: well developed, with TWO IN RIGHT VALVE AND ONE IN LEFT valve in most specimens
- nacre: white to bluish
SOFT TISSUES:
SIMILAR SPECIES/LOOKALIKES: the small size and very restricted geographical range make this rare species easy to identify. The aberrant/reversed lateral tooth arrangement on its own is diagnostic when present. IMPORTANT NOTE: this species is considered extirpated/extinct at this point in Canada, as it hasn't been found since 1968.
Sources and Credits
- A.E. Bogan, J. Alderman, and J. Price, no known copyright restrictions (public domain), http://commons.wikimedia.org/wiki/File:Alasmidonta_heterodon.jpg
- Adapted by Philippe Blais from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Alasmidonta_heterodon
