|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Nucula (Acila) stillwaterensis
Bivalvia - Protobranchia - Nuculidae
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|C. E. Weaver and K. Palmer 1922||Shell small, rectangular in outline ; anterior dorsal margin
nearly straight, posterior ventral margin nearly straight, sloping to a broadly
rounded anterior end which approaches the dorsal margin with greater convexity ;
escutcheon impressed but not defined by an incised line ; central portion of the
area of the escutcheon raised, protruding slightly beyond the posterior margin;
surface ornamented with radiating ribs medium in strength; above the central
portion of the shell the divarication is single, below the mid-area the series of
divarication is comparatively wide, the duplication increasing ventrad forming
five sets along the ventral margin ; the area of divarication occupying the middle
third of the ventral portion of the shell ; lunule not defined ; surface with heavy,
impressed growth lines forming wide undulations on the surface of the shell.