Spondylopecten (Plesiopecten) subspinosus (Schlotheim, 1820)

Plate 4, fig. 3

1820 Pectinites subspinosus - Schlotheim: 223.

1938 Plesiopecten subspinosus (Schlotheim) - Weir: 50, pl. 3, fig. 18.

1952 Chlamys (Plesiopecten) subspinosa (Schlotheim) - Cox: 18, pl. 1, figs 9-12.

1995 Spondylopecten (Plesiopecten) subspinosus (Schlotheim 1820) - Jaitly et al.: 194, pl. 18, figs 14-15.

Material.

One composite mould of a right valve and one external mould from the upper part of the lower member at the Hikkim-Kaza road (SNSB-BSPG 2020 XCIX 23).

Description.

Specimens small (H: 5.4 mm; K: 5.8 mm), suborbicular, equilateral, weakly inflated. Auricles large, distinctly separated from disk, anterior one incomplete. Surface of composite mould covered with 11-13 positive radial structures interpreted herein as corresponding to radial ribs, which are angular and show a tendency to bifurcate towards the ventral margin.

Remarks.

Despite the poor preservation of the specimens (lack of shell), they can be safely assigned to S. (Plesiopecten) subspinosus, based on the number and angularity of their ribs (compare Johnson 1984, p. 84).