Parthenina sp. 2, Bucquoy, Dautzenberg & Dollfus, 1883

Thivaiou, Danae, Harzhauser, Mathias & Koskeridou, Efterpi, 2019, Early Miocene Gastropods from the Felli Section (Proto-Mediterranean Sea NW Greece), Geodiversitas 41 (8), pp. 323-366 : 354-355

Parthenina sp. 2

(Fig. 8 G1, G2)

MATERIAL EXAMINED. — Sample F11: AMPG ( IV) 2575, 2576 (two incomplete specimens).

DIMENSIONS. — Maximum height: 1.18 mm

DISTRIBUTION. — Early Miocene. Proto-Mediterranean Sea: Greece (this paper).

DESCRIPTION

Elongated pupoid small shell; type C smooth protoconch. Apex blunt; first teleoconch whorl flat. Three teleoconch whorls preserved, whorls 2 and 3 almost flat; axial sculpture consists of slightly sigmoidal and opisthocline rounded ribs; spiral sculpture includes one abapical cord present between ribs. Sutures deep, V-shaped. Narrow umbilicus; columellar tooth present; aperture missing.

REMARKS

The present shell is morphologically very close to Parthenina obtusa (Brown, 1817) as illustrated by Landau et al. (2013). Nevertheless, the Greek species differs in having a marked angulation close above the lower suture from the first teleoconch whorl on, and steeper flanks. In the stratotype region of the Aquitanian (SW France), Parthenina degrangei ( Cossmann & Peyrot, 1917) has a similar axial sculpture ( Lozouet et al. 2001) that becomes more strongly opisthocline on the last whorl, and bear two spiral cords above the lower suture on the two last teleoconch whorls whereas the Greek species only has one.

Figures

FIG. 8. — A1, A2, ‘Odostomia’ sp. 2, AMPG(IV) 2558; B1-B3, Megastomia sp. 1, AMPG(IV) 2560; C1, C2, Brachystomia sp., AMPG(IV) 2570; D1-D3, Megastomia sp. 2: D1, AMPG(IV) 2563;D2, D3, AMPG(IV) 2564;E1-E4, Pyramistomia aliakmoni n. sp.: E1, E2, holotype, AMPG(IV) 1500;E3, paratype 1, AMPG(IV) 1501 (SEM image); E4, AMPG(IV) paratype 1, AMPG(IV) 1501, protoconch (SEM image); F1-F4, Parthenina sp. 1: F1, F2, AMPG(IV) 1573; F3, AMPG(IV) 1574 (SEM image); F4, AMPG(IV) 1574, apex (SEM image); G1, G2, Parthenina sp. 2: G1, AMPG(IV) 2575; G2, AMPG(IV) 2575, apex (SEM image); H,?Syrnola sp., AMPG(IV) 2577 (SEM image). Scale bars: A1, A2, B1-B3, D1, G1, H, 500 µm; C1, C2, D2, D3, E1, E2, 1 mm; E3, F1, F2, 400 µm; E4, F3, 200 µm; F4, G2, 100 µm.