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Cyrtonotella nicholsoni

Rhynchonellata - Orthida - Archaeorthidae

Taxonomy
Stropheodonta nicholsoni was named by Reed (1917).

It was recombined as Cyrtonotella nicholsoni by Williams (1962).

Sister species lacking formal opinion data

View classification of included taxa

Synonymy list
YearName and author
1917Stropheodonta nicholsoni Reed p. 898 figs. pl. xvii, fig. 21 ; pl. xviii, figs. 1-8
1962Cyrtonotella nicholsoni Williams p. 106 figs. Pl. IX, figs. 1, 2, 5, 6

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RankNameAuthor
kingdomAnimalia()
Triploblastica
Eutriploblastica
Neotriploblastica
Eucoelomata
superphylumLophotrochozoa
Lophophorata
phylumBrachiopodaCuvier 1805
RankNameAuthor
subphylumRhynchonelliformeaWilliams et al. 1996
classRhynchonellataWilliams et al. 1996
orderOrthidaSchuchert and Cooper 1932
suborderOrthidinaSchuchert and Cooper 1932
superfamilyOrthoideaWoodward 1852
familyArchaeorthidae
genusCyrtonotellaSchuchert and Cooper 1931
speciesnicholsoni()

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
A. Williams 1962Large, subquadrate Cyrtonotella less commonly with an alate hinge-line, profile gently concavo-convex with a broad, low sulcus in the brachial valve tending to become obsolescent anteriorly, brachial valve slightly more than two-thirds as long as wide; shell surface costellate in four generations and commonly finely developed and closely spaced at 10 to 13 per 5 mm. antero-medianly, exceptionally as coarse as 7 costellae per 5 mm. ; ventral muscle-scar squat, about three-quarters as long as wide and extending anteriorly for less than one-third the length of the valve, median adductor scar narrowly lanceolate, enclosed by diductors which extend anterior to them as a pair of narrow impressions passing into vaguely impressed vascula media; cardinal process bulbous, notothyrial platform broad and low, brachiophores subparallel with hinge-line.