Seguenzia elegans Jeffreys 1885

• Main Authors: Salvador, Rodrigo B., Cavallari, Daniel C., Simone, Luiz R. L.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2014
• Subjects: Biodiversity; Taxonomy; Animalia; Mollusca; Gastropoda; Seguenziida; Seguenziidae; Seguenzia; Seguenzia elegans; North Atlantic
• Online Access: https://doi.org/10.5281/zenodo.6138470; http://treatment.plazi.org/id/7B1480144B45FF9BFF7AFB8CD34DC0B9

Seguenzia elegans Jeffreys, 1885 (Figs. 19–21) Seguenzia elegans Jeffreys, 1876: 201 [ nomem nudum ]. Seguenzia elegans Jeffreys, 1885: 42 (pl. 5, fig. 1–1a); Clarke, 1959: 232; Clarke, 1961: 350 (pl. 2, figs. 5, 7; pl. 3, fig. 5); Abbott, 1974: 38; Gofas et al ., 2001: 184, Segers et al. , 2009: 5. Seguenzia cf. elegans : Quinn, 1983b: 728 (figs. 5, 26). Type locality: Porcupine Expedition, 1870, Atl. St. 16, 17, 17a, off the coast of Portugal, 740–1095 fathoms (ca. 1350–2000 m depth) (Jeffreys 1885). Distribution: North Atlantic: Bay of Biscay, off Portugal (Jeffreys 1885); off Bermuda (Clarke 1959); off Yucatan, Mexico (Quinn 1983b). South Atlantic: Cape Basin and Argentine Basin (Clarke 1961). New occurrence: Southeastern Brazil, Espírito Santo, from 1540 to 3450 m depths. Description: Shell small, conical, relatively thin-walled, with stepped spire. Color translucent to nacreous glossy white. Protoconch (~1 whorl) prominent, bulbous, microporous; transition to teleoconch sometimes visible as an orthocline line, but not always well-marked. Teleoconch sculpture (except whorl base) consisting of strong spiral cords, with well-marked axial threads and very fine spiral threads between cord and suture; spire whorls bearing two visible spiral cords: a weaker subsutural one, and a stronger supramedian that produces a distinct keel; a third strong cord (though weaker than the supramedian) can be observed emerging below the abapical suture. Distance between axial riblets roughly equal to three times rib width; axial threads prosocline above median keel and opisthocline below it, creating a continuous sigmoid pattern. Whorl base sculptured by 8–10 spiral cords; axial threads between cords, becoming fainter toward umbilicus. Whorls slightly concave between spiral cords, but with overall rounded profile. Suture obscured by subsutural spiral cord. Aperture rounded quadrangular, with wellmarked callus, strong columellar tooth, and three labral sinuses: a deep subsutural sinus; a shallow sinus in peripheral part of basal ...