Fawnsfoot

Truncilla donaciformis

DIAGNOSTICS 5

SHELL

  • size: small
  • thickness: thick
  • shape: oval, pointed posterior
  • width: inflated
  • surface: smooth, matte
  • color/markings: yellowish to greenish or pale brown; thin to wide faint green rays overlaid with very variable darker chevrons, dashes or blotches (pattern may alternate through growth bands)
  • beaks: full, elevated, almost central; sculptures: faint double-looped bars; junction of anterior hinge and anterior ridge silhouette forms a SMOOTH open angle
  • sexual dimorphism: subtle
  • pseudocardinal teeth: moderate size; posterior one on left valve long/pointed and curved dorsally
  • lateral teeth: moderate size, straight
  • nacre: bluish white

Soft parts: ----

Similar species/lookalikes: Most similar to young Epioblasma triquetra and Truncilla truncata. Markings on E. triquetra usually include some filled-in chevrons or downward pointing triangles. T. truncata is more drop-shaped with a more pointed posterior end and a more rounded in anterior, a sharper posterior ridge, and beaks are closer to anterior, but these features are less obvious in young animals. Coloring and markings can be very similar and as variable as in T. donaciformis.

Shell silhouette at junction of anterior hinge and anterior ridge forms a SMOOTH open angle, compared with the SHARP angle in T. truncata. This feature can be very helpful to differentiate larger specimens of T. donaciformis from smaller ones of T. truncata when all other criteria aren't conclusive

DISTRIBUTION/WATERSHEDS 5

ONTARIO

  • Saugeen R. (?)
  • Sydenham R.
  • Thames R.
  • Grand R.

Sources and Credits

  1. (c) Philippe Blais, some rights reserved (CC BY-NC-ND), uploaded by Philippe Blais
  2. (c) MC Barnhart, some rights reserved (CC BY-NC), uploaded by MC Barnhart
  3. (c) Jeff Garner, some rights reserved (CC BY-NC), uploaded by Jeff Garner
  4. (c) Scott Gibson, some rights reserved (CC BY-NC), uploaded by Scott Gibson
  5. (c) Philippe Blais, some rights reserved (CC BY-SA)

More Info

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