Bairdoppilata

Bairdoppilata sp. 6

(Figs. 3.11b, 4, 17)

1974 in part Bairdoppilata sp. 44, Hartmann: 253.

Material. 3 LV, 3 RV, Lüderitz Bay, Namibia, ZMH K­ 30070. These specimens were studied but not illustrated by Hartmann (1989).

Distribution. Lüderitz Bay, Namibia, Southeastern Atlantic.

Measurements. A LV, L 1.34mm, H 0.82mm; (A­?1) RV, L 1.17–1.20mm, H 0.62–0.64mm; (A­?2) LV, L 0.98–1.00mm, H 0.60mm; (A­?2) RV, L 0.99mm, H 0.54mm.

Description. LV subtriangular in lateral view, anterior conspicuously more broadly rounded than posterior, fairly caudate, dorsal margin steeply angulate, posterior margin upswung. LV subhexagonal in lateral view, anterior conspicuously more broadly rounded than posterior, slightly caudate, dorsal tri­segmented, but with inconspicuous angles, anterior and posterior segments slightly concave, posterior margin upswung. Valve surface punctuated. Normal pore canals with faint rim, sensilla short to long. Fringes present on anterior and posterior margins of RV. Calcified inner lamella narrow, vestibules constricted. Hinge anterior and posterior elements with 3 fairly conspicuous denticles and sockets. Nine adductor muscle scars present, eight of them positioned in a circle surrounding the ninth scar.

Remarks. The specimens herein identified as Bairdoppilata sp. 6 were also identified by Hartmann (1974) as Bairdoppilata sp. 44, and assigned to B. simplex by Dingle (2003). Bairdoppilata sp. 6 differs from B. simplex and ? B. labiata, because the former species presents: (1) punctuate valve surface (Fig. 17.A); (2) more acute, non­denticulate posterior margin of RV (Fig. 17.E–F); (3) more conspicuous hinge denticulation; (4) anterior and posterior barbed fringes on RV (Fig. 17.C, F, G).

Considering the six valves studied herein, maybe the smaller, more angulate and caudate specimens (Fig. 17.N–P) belong to another species than the larger specimens (Fig. 17.A–M).