Amnicythere aff. striatocostata (Schweyer, 1949) Stancheva, 1990

RAUSCH, LEA, STOICA, MARIUS & LAZAREV, SERGEI, 2020, A Late Miocene - Early Pliocene Paratethyan Type Ostracod Fauna From The Denizli Basin (Sw Anatolia) And Its Palaeogeographic Implications, Acta Palaeontologica Romaniae 16 (2), pp. 3-56 : 30-35

Amnicythere aff. striatocostata

Fig. 21 j-n

Description. The carapace has an elongated shape in lateral view. The dorsal and the ventral margin run parallel to one another. The ventral margin is depressed medially whereas the hinge margin is almost straight.

The transition onto the slightly rounded posterior end is obtuse and in the posterodorsal area a hinge ear can appear more or less pronounced. The margin is slightly compressed and, in any case, appears less rounded than the anterior end. The anterior-and the posterior boarder lack any ornamentation but occasionally contain rare conulus. In the center of the valve weakly pronounced longitudinal running ribs are present that are covered by a deep reticulated pattern that covers almost the entire horizontal width of the carapace. The inner lamella is widely pronounced and the hinge and muscle scar are typical of this genus. Dimension: L = 0,32 – 0,45 mm, H = 0,17 – 0,22 mm, the minimum sizes include juveniles too.

Remarks. This species shows clear resemblance to A. striatocostata but is much smaller. Also, the general outline is more subrectangular. The parallel running ribs are somewhat concentrated in the central part of the valve and the ornamentation between them consists mainly of deeper rounded, polygonal pits. A morphologically similar species has been described by Olteanu (1995, 1998) under the name Euxinocythere schweyeri from the Pontian and Dacian deposits of the Dacian Basin. The species however has a less pronounced ornamentation pattern.

Figures

Fig. 21a-i Amnicythere striatocostata; a LV, external view, ♂; b RV, external view, ♂; c LV, external view, ♀; d RV, external view, ♀; e RV, internal view, ♀; f LV, internal view, ♀; g RV, external view, A1 juvenile; h RV, external view, A2 juvenile; i RV, external view, A3 juvenile; j-n Amnicythere aff. striatocostata; j LV, external view,?♀; k, l RV, external view, ♀; m RV, internal view,?♀; n. RV, external view,?♂; (all specimens from section A, samples 0 m – 35,5 m).