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Nucula (Acila) stillwaterensis

Bivalvia - Protobranchia - Nuculidae

Synonymy list
YearName and author
1922Nucula (Acila) stillwaterensis Weaver and Palmer p. 6 figs. pl. 8, fig. 8

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RankNameAuthor
kingdomAnimalia()
Bilateria
EubilateriaAx 1987
Protostomia
Spiralia
Schizocoela
phylumMollusca
classBivalvia
RankNameAuthor
orderProtobranchiaPelseneer 1889
superorderNuculiformiiDall 1889
orderNuculida(Dall 1889)
superfamilyNuculoidea(Gray 1824)
familyNuculidaeGray 1824
genusNuculaAdams and Adams 1858
subgenusAcila
speciesstillwaterensis

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.

Diagnosis
ReferenceDiagnosis
C. E. Weaver and K. Palmer 1922Shell 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.