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Sphenotus monroensis

Bivalvia - Grammysiidae

Taxonomy
Pleurophorus monroensis was named by Worthen (1884). It is a 3D body fossil.

It was recombined as Sphenotus monroensis by Busanus and Hoare (1991) and Hoare (1993).

Sister species lacking formal opinion data

Synonyms
Synonymy list
YearName and author
1884Pleurophorus monroensis Worthen p. 17
1890Pleurophorus monroensis Worthen p. 125 figs. pl. 18 f. 3, 3a
1930Sphenotus acutiliratus Croneis figs. pl. 18 f. 11
1930Sphenotus vulgaris Croneis figs. pl. 15 f. 17
1974Sanguinolites acutiliratus Busanus p. 251 figs. pl. 9 f. 8
1991Sphenotus monroensis Busanus and Hoare p. 475 figs. 6.1 – 6.6
1993Sphenotus monroensis Hoare p. 390 figs. 7.3 – 7.4

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RankNameAuthor
kingdomAnimalia()
Bilateria
EubilateriaAx 1987
Protostomia
Spiralia
superphylumLophotrochozoa
phylumMollusca
classBivalvia
Eubivalvia
RankNameAuthor
subclassAutobranchia(Groblen 1894)
infraclassHeteroconchia(Gray 1854)
CardiomorphiFerussac 1822
CardioniFerussac 1822
CardiidiaFerussac 1822
superfamilyGrammysioideaMiller 1877
familyGrammysiidaeMiller 1877
genusSphenotus
speciesmonroensis()

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.

Sphenotus monroensis Worthen 1884
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Invalid names: Sanguinolites acutiliratus Croneis 1930 [synonym], Sphenotus vulgaris Croneis 1930 [synonym]
Diagnosis
ReferenceDiagnosis
J. W. Busanus and R. D. Hoare 1991Sphenotus with dorsal and ventral margins diverging posteriorly; distinct, angular, umbonal ridge extending to ventroposterior angle; radial ornamentation on the posteroumbonal area lacking; posterior margin with gentle convexity; ventral margin straight to slightly sinuous; prominent, anterior adductor muscle scar set off by narrow, high ridge; surface with fine growth lines that become more prominent anteriorly.

Sphenotus monroensis differs from S. vulgaris Girty, 1915, and S. striatogranulatus Hind, 1900, by having a more angular posterior margin and being more attenuate anteriorly. Sphenotus washingtonensis (Girty, 1910) has a radial rib between the umbonal ridge and the dorsal margin. Sphenotus pisinnus Hoare, Heaney, and Mapes, 1989, lacks a distinct umbonal ridge and the dorsal and ventral margins do not diverge posteriorly.
R. D. Hoare 1993Sphenotus with subparallel ventral and dorsal margins; anterior margin produced, curving sharply at mid-height just below well developed lunule; posterior margin truncate; beaks prosogyrate, depressed; escutcheon well developed; strong umbonal ridge sloping to posteroventral margin; surface marked by several coarse, comarginal folds, more prominent ventrally; large anterior adductor scar buttressed posteriorly.