Cytheropteron sp. 1

Wannenmacher, Norbert, Dietze, Volker, Franz, Matthias & Schweigert, Guenter, 2021, New records of ostracods and ammonites from the Aalenian (mainly Concavum Zone) of the Zollernalb (Swabian Alb, SW Germany), Zitteliana 95, pp. 1-55 : 10

? 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

Figures

Figure 11. (1) Balowella catena (Franz et al.), SMNS 70521 / 80, C, right view, L: 0.329 mm; sample He 19 - 18. (2, 3);? Cytheropteron sp. 1, (2) SMNS 70521 / 81, LV, L: 0.322 mm; sample He 19 - 27; (3) SMNS 70521 / 82, RV, L: 0.355 mm; sample He 19 - 27. (4, 5) Procytheropteron aff. gramanni Brand, (4) SMNS 70521 / 83, LV, L: 0.373 mm; sample He 19 - 26; (5) SMNS 70521 / 84, RV, L: 0.305 mm; sample He 19 - 22. (6) Procytheropteron sp. 1 Franz et al., SMNS 70423 / 66, LV, L: 0.322 mm; sample G 20 b; (7) Aphelocythere recta Ohmert, SMNS 70521 / 85, C, right view, L: 0.460 mm; sample Ro 19 - 4. (8) Aphelocythere aff. recta, SMNS 70521 / 86, C, right view, L: 0.466 mm; sample Ro 19 - 4. (9) Aphelocythere sp. 1, SMNS 70521 / 87, RV, L: 0.630 mm; sample He 19 - 27; (10) " Asciocythere " sp., SMNS 70521 / 88, RV, L: 436 mm; sample He 19 - 26. (11) Eocytheridea elongata Bate, SMNS 70521 / 89, RV, L: 0.573 mm; sample He 19 - 21. (12) Eocytheridea lacunosa Bate, SMNS 70521 / 90, RV, L: 0.705 mm; sample He 19 - 25; (13, 14) Praeschuleridea cf. subtrigona, (13) SMNS 70521 / 91, C, right view, L: 0.512 mm; sample Ro 19 - 5; (14) SMNS 70521 / 92, RV, inner view, L: 0.512 mm; sample Ro 19 - 5; (15 - 17) Praeschuleridea sp. 1, (15) SMNS 70521 / 93, C, right view, L: 0.490 mm; sample He 19 - 27, (16) SMNS 70521 / 93, C, right view, (detail); (17) SMNS 70521 / 94, RV, L: 0.620 mm; L: 0.620 mm; sample He 19 - 27. (18) Pleurocythere ohmerti Franz et al., SMNS 70521 / 94, LV, L: 0.479 mm; sample Tst. 38 - 1988 (= He 19 - 27). Achdorf Formation, Upper Aalenian, (1, 6) Bradfordensis Zone (Gigantea Subzone), (2 - 5, 7 - 18) Concavum Zone. Scale bars (if not indicated otherwise): 20 μm.