Mohrensterniinae Korobkov, 1955

Kowalke, Thorsten & Harzhauser, Mathias, 2004, Early ontogeny and palaeoecology of the Mid-Miocene rissoid gastropods of the Central Paratethys, Acta Palaeontologica Polonica 49 (1), pp. 111-134 : 125

Subfamily Mohrensterniinae Korobkov, 1955

Diagnosis (supplement).— Mohrensterniinae are characterised by low−conical protoconchs usually comprising 2–2.75 whorls measuring 0.3–0.5 mm in maximum diameter with small embryonic shells (only species with indirect development are known). Protoconchs are characterised by fine spirally sculptured embryonic shells and larval shells which are smooth except for growth lines. The transitions from the embryonic shell to the larval shell and from the larval shell to the teleoconch are only slightly thickened and often indistinct. No marked sinusigera notch is present.

The monogeneric subfamily Mohrensterniinae ranges stratigraphically from the early Middle Miocene (Early Badenian, Tarkhanian) to the early/mid Late Miocene (Maeotian).

Differences.— Mohrensterniinae differ from Rissoinae with similar teleoconch in their protoconch morphology, by lacking any larval sculpture aside from growth lines and by lacking a marked thickened sinusigera notch in transition to the teleoconch. This transition is often indistinct, only indicated by the successive onset of the adult sculpture. If a rim terminates the protoconch, this is only slightly thickened and slightly sinuous in course. Rissoininae differ by lacking embryonic sculpture in the case of indirect development; this sculpture is present in Mohrensterniinae . Mohrensterniinae differ from Hydrobiidae and Assimineidae by lacking a groove−ridge pattern ornamenting the embryonic shell and by lacking spiral larval sculpture (cf. Kowalke 1998).