Alvania 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 : 61

Alvania sp.

Fig. 3a

Material: one specimen ( PMBBU 23853 )

Description: Conical shell consisting of 6 whorls up to 2.38 mm in height and 1.55 mm in width. The protoconch consists of 2.5 convex whorls ornamented with very fine grained spiral threads. Teleoconch flattened profile and with canaliculated suture are. The ornamentation consists of axial ribs intersected by spiral threads; prominent, rounded knots result at the junction. On the first whorl, the ornamentation is represented by three spiral threads intersected by 11 axial ribs. The last whorl represents about 70% of the total shell height. The ornamentation includes 23 axial ribs and 10 spiral threads covering also the base of the shell. The aperture is rounded and slightly sharpened towards the upper part. The inner lip covers the umbilicus. The external lip is thickened due to an external varix; it presents inner denticles.

Remarks: This species is similar to recent A. cimex (Pliocene-Recent) in general shape (see Garilli & Parrinello, 2012, fig 6A, B). Sacco (1895, p.24, pl. 1, fig. 56) described from Miocene of Italy Acinus cimex var. tauroparva that resemble our specimen (see Ferrero Mortara et al, 1984, pl.38, fig. 9 who illustrates the collection of type species describer by Bellardi and Sacco).

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).