Seguenzia cf. elegantissima Poppe, Tagaro & Dekker, 2006

Helwerda, Renate Ariane, Wesselingh, Frank Pieter & Williams, Suzanne T., 2014, On some Vetigastropoda (Mollusca, Gastropoda) from the Plio-Pleistocene of the Philippines with descriptions of three new species, Zootaxa 3755 (2), pp. 101-135 : 110

Seguenzia cf. elegantissima Poppe, Tagaro & Dekker, 2006

( Figures 10–12 )

2006 Seguenzia elegantissima nov. spec.—Poppe, Tagaro & Dekker: p. 26, pl. 3, fig. 2. 2008a Seguenzia elegantissima —Poppe & Tagaro: p. 162, pl. 26, fig. 4.

Material. Anda 6 (6); AndaDeVos (18); AndaClif3 (7); Tiep 1 (1).

Characterization. High spired, H 2.3 mm, W 1.9 mm; P 1.1 whorls, with erect nucleus and two discontinuous spiral ribs, DN 0.11–0.14 mm; T with fine but regular and well developed axial lirae on early whorls, fading on later whorls; slightly erect upper keel; markedly beaded subsutural cord on later T whorls; body whorl with three peripheral spiral ribs and four basal spiral ribs; columellar lip with low basal fold or broadly folded; upper apertural sinus pronounced and thickened.

Distribution. Apart from the studied material, this species is known only from the type locality in the Bohol Sea, Philippines, from 679–740 m water depth ( Poppe et al. 2006).

Remarks. The elongate shape, thin and regular axials, the beaded suprasutural ridge and the folded columellar lip distinguish this species from the two species treated above. The assignment of the present material to S. elegantissima is uncertain, because the outer lip is severely damaged in all specimens, making a complete comparison with the material described by Poppe et al. (2006) impossible. Furthermore the subsutural spiral ridge appears to be smooth to marginally knobby in the recent species, whereas it is distinctly beaded in the fossil material studied here. Seguenzia praeceps Marshall, 1991 , S. fulgida Marshall, 1983 and S. serrata Marshall, 1983 are quite similar in shape, but their subsutural ridge is not as strongly crenulated as in the studied material.

Figures

FIGURES 8 – 12. Seguenziidae. 8. Seguenzia donaldi Ladd, 1982. RGM 608.215. Locality AndaDeVos. (a) rear view, (b) apertural view, (c) side view, (d) basal view, (e) apical view. 9. Seguenzia donaldi Ladd, 1982. RGM 608.216. Locality Anda 3. (a) rear view, (b) apertural view. 10. Seguenzia cf. elegantissima Poppe, Tagaro & Dekker, 2006. RGM 608.221. Locality AndaDeVos. (a) rear view, (b) apertural view, (c) side view, (d) basal view, (e) apical view. 11. Seguenzia cf. elegantissima Poppe, Tagaro & Dekker, 2006. RGM 608.222. Locality AndaDeVos. (a) rear view, (b) apertural view, (c) spire. 12. Seguenzia cf. elegantissima Poppe, Tagaro & Dekker, 2006. RGM 608.223. Locality AndaDeVos. SEM detail of protoconch.