Bittium rubanocinctum Glibert, 1958

Bittium rubanocinctum Glibert, 1958 ( Fig. 5F View FIG 1-F View FIG 3 View FIG )

Bittium rubanocinctum Glibert, 1958: 7 , pl. 2, figs 3a-c.

MATERIAL AND DIMENSIONS. — Maximum height 6.1 mm, width 1.8 mm. — RGM.1364907 (2), leg. WG ; RGM.1364972 (46), leg. ACJ ; RGM.1365268 (1), leg. ACJ ; RGM.1365072 (70), leg. AWJ ; RGM.1365284 (1), leg. AWJ ; RGM.1365375 (1), leg. AWJ .

SPECIES CHARACTERISATION. — Robust turriform shell with pronounced suture. Broad paucispiral protoconch of two smooth whorls. Teleoconch whorls with three spirals cords and slightly prosocline axials ribs forming low tubercles at intersections.

DISTRIBUTION. — Lower Pliocene: NSB, Kattendijk Formation, Belgium (Glibert 1958), Oosterhout Formation, the Netherlands (RGM collections). — Lower Pleistocene: Atlantic, Selsoif, France (this paper).

REMARKS

The Selsoif specimens have more robust axials and lower tubercles that make it slightly different from the specimens illustrated by Glibert (1958) that tend to have finer ribs and less pronounced knobs. Otherwise, the number and organisation of the ribs and cords of the Early Pliocene North Sea Basin (NSB) specimens and the Selsoif material are identical. The geographical and temporal distribution gap between the NSB Early Pliocene and French Gelasian occurrences is remarkable. A Bittium species illustrated by Harmer (1916: pl. 41, fig.4) as B. reticulatum trinodosa (Etheridge & Bell) from St Erth also has three prominent spirals.However, the spirals and axials are very regularly spaced and form an evenly reticulated surface pattern. The synonymisation of B. rubanocinctum with B. neerlandicum (Beets) by Wesselingh et al. (2012: 42) is not substantiated.