Sinezona marrowi Geiger 2012

Helwerda, Renate A. & Wesselingh, Frank P., 2014, Revision of Scissurellidae, Anatomidae and Fissurellidae (Gastropoda: Vetigastropoda) from the Plio-Pleistocene of the Philippines, Zootaxa 3838 (2), pp. 183-194 : 186

Sinezona marrowi Geiger 2012

( Figures 2–3 )

2012 Sinezona marrowi nov. spec.—Geiger: p. 500–503, figs 379–381.

Material. Anda1 (1) RGM 961.706, Tiep2 (1) RGM 961.707.

Characterization. Shell with flattened apex and inflated base; H 0.80 mm, W 1.04 mm; P with axial sculpture, DN 0.06–0.09 mm; T1 with strong prosocline axial lamellae and fine spiral cords; axial lamellae weaker on T2; aperture large, inclined; umbilical wall straight; umbilical ridge thin but prominent.

Distribution. Indian Ocean and Indo-Malayan Archipelago, 0–434 m depth (Geiger 2012).

Remarks. The studied material conforms to the description by Geiger (2012), except for the umbilical ridge, which appears to be more prominent in the studied material. The development of the slit cannot be observed in this juvenile material.

Figures

FIGURES 1 – 5. 1. Scissurella mirifica (A. Adams, 1862). RGM 961.705. Locality Tiep 3. (a) rear view, (b) apertural view, (c) basal view, (d) apical view. For these and remaining figures, all material derives from the Piacenzian or Gelasian Santa Cruz Formation of Cabarruyan Island or nearby Luzon Island, Philippines. Scale bars shells = 500 µm, scale bars SEM = 100 µm. 2. Sinezona marrowi Geiger, 2012. RGM 961.706. Locality Anda 1. (a) rear view, (b) apertural view, (c) basal view, (d) apical view, (e) SEM detail of teleoconch, (f) SEM detail of protoconch. 3. Sinezona marrowi Geiger, 2012. RGM 961.707. Locality Tiep 2. (a) rear view, (b). 4. Sukashitrochus morleti (Crosse, 1880). RGM 961.708. Locality Anda 2. (a) rear view, (b) apertural view, (c) basal view, (d) apical view, (e) SEM apical view, (f) SEM detail of teleoconch, (g) SEM detail of protoconch. 5. Sukashitrochus morleti (Crosse, 1880). RGM 961.709. Locality Anda 4. (a) SEM detail of teleoconch.