? Cytheropteron sp. 1

Fig. 11: 2, 3

Material.

3 RV, 4 LV in samples He19-25 - Ha19-3.

Occurrence.

Upper Aalenian, Bradfordensis Zone (Gigantea Subzone) to Concavum Zone; SW Germany.

Description.

Very small, triangular. Anterior margin rounded with extremity slightly below mid-height; posterior margin pointed, apex below mid-height. Cardinal angles rounded in left valve, cardinal angles pronounced in right valve.

Right valve: Dorsal margin straight, medianly slightly convex, ventral margin slightly convex, medianly partly obscured by a median overhang of the lateral curvature. The punctate shell surface is longitudinally and vertically strongly curved with a ventral overhang. The curvature is concavely recessed in the uppermost area along a sharp oval bend, ending in a weak anteromedian lobe. A narrow anterodorsal depression parallel to the anterior margin is limited by a short, slightly curved frontal rib, ending above mid-height.

Left valve: Dorsal margin strongly convex, otherwise identical to the right valve.

Hinge due to poor preservation not clearly visible, possibly merodont; other internal details not observed.

Genus Procytheropteron Ljubimova, 1955