Manzonia sp.

TĂMAȘ A., TĂMAȘ D. M. & POPA M. V., 2013, Badenian Small Gastropods From Lăpugiu De Sus (Făget Basin, Romania). Rissoidae Family, Acta Palaeontologica Romaniae 9 (1), pp. 57-66 : 63

Manzonia sp.

Fig. 3c

Material: one specimen from L5 ( PMBBU 23861 ) Description: Juvenile specimen with five scalariform whorls; 1.55 mm in height and 0.9 mm in width. Protoconch contain of about two convex whorls. Ornamentation is not visible under stereomicroscope. Teleoconch ornamented with axial ribs intersected by less-pronounced spiral threads; in-between the main threads one can notice other extremely fine spiral threads. The last whorl represents about 65% of the total shell height. Ornamentation consists of 14 axial ribs intersected by five spiral threads. Two additional, well-defined spiral threads are present towards the base. Round aperture with strongly thickened peristome .

Remarks: This specimen is similar with a juvenile Manzonia scalaris in general shape but differ in protoconch larger diameter and more flatten whorls and it also differ from M. subzetlandica by its broad opisthocline axial ribs and subordinate spiral threads.

Figures

Fig. 3 - a Alvania sp. b Manzonia (Manzonia) scalaris (Dubois, 1831). c Manzonia sp. d Rissoina (Phosinella) steinabrunnensis Sacco 1895. e Rissoina (Rissoina) vindobonensis Sacco, 1895. f Rissoina (Rissoina) pusilla (Brocchi, 1814).