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Cyrtulotibia
Taxonomy
Cyrtulotibia was named by Eames (1957) [Sepkoski's age data: T Eo-m Sepkoski's reference number: 1074]. Its type is Rostellaria unidigitata.
It was assigned to Strombidae by Eames (1957); to Neotaenioglossa by Sepkoski (2002); and to Rostellariidae by Pacaud (2008).
It was assigned to Strombidae by Eames (1957); to Neotaenioglossa by Sepkoski (2002); and to Rostellariidae by Pacaud (2008).
Species
Synonymy list
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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
Reference | Diagnosis | |
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F. E. Eames 1957 | Form somewhat like that of a Tibia with a very short, inclined siphonal canal ; often developing a strong shoulder on the last whorl and thus recalling Cyrtulus. Protoconch conic, of two or three smooth, moderately convex whorls. Spire like that of Tibia, conic, of five or six gently convex whorls ; early stages with fine axial riblets, which are orthocline above and opisthocline below (i.e., concave forwards), crossed by increasingly broad spiral threads ; coarse, swollen varices developed occasionally. On later spire whorls the axial riblets become obsolete and are represented by accentuated growth lines only. Last whorl slightly to very strongly shouldered, the more strongly shouldered specimens with a narrow callous band (an extension of the callus of the posterior sinus) extending back some one and a half to two whorls along the sutural region. Last whorl smooth except for spiral threads on the base, rather conic, base very slightly excavated, neck oblique. Rostrum short, curved to the right. Aperture oval, with a narrow, slit-like posterior sinus curving back on to the suture ; columellar lip callous, developing a prominent, raised knob of callus limiting the inner side of the posterior sinus ; a broad notch to the right of the rostrum is delimited on the right by a short spine. Outer lip rather thick, not varicose, internally smooth, with no additional spines, gently parasigmoidal, distinctly opisthocline as a whole. |