Turbonilla s.l. sp. 3, Risso, 1826

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 : 356-357

Turbonilla s.l. sp. 3

(Fig. 9 C1, C2)

MATERIAL EXAMINED. — Sample F11: AMPG ( IV) 2584-2585 (two specimens).

DIMENSIONS. — Maximum height: 1.25 mm

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

DESCRIPTION

Type A2 helicoidal protoconch; four convex teleoconch whorls preserved. Protoconch forms an angle of about 105° with the axis of the shell. Teleoconch sculpture consists of closely and regularly spaced prosocline fine axial ribs. Inconspicuous columellar fold; aperture missing.

REMARKS

A third species of Turbonilla is present.The sculpture is reminiscent of Turbonilla sp. 1, but the axial ribs are less prominent, more rounded and more closely spaced; the whorls are also more convex.

Figures

FIG. 9. — A1-A3, Turbonilla (s.l.) sp. 1, AMPG(IV) 2580; B1-B3, Turbonilla (s.l.) sp. 2, AMPG(IV) 2583; C1, C2, Turbonilla (s.l.) sp. 3, AMPG(IV) 2584; D1-D3, Turbonilla (s.l.) sp. 4: D1, AMPG(IV) 2586 (SEM image); D2, D3, AMPG(IV) 2687. Scale bars: 500 µm.