Pyrunculus sp., Pilsbry, 1895

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 : 348

Pyrunculus sp.

(Fig. 7 E1, E2)

MATERIAL EXAMINED. — Sample F11: AMPG ( IV) 2545, 2546 (two specimens [1 incomplete]).

DIMENSIONS. — Maximum height: 2.80 mm.

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

DESCRIPTION

Shell small, fragile, elongated pyriform, one whorl visible. Sculpture of fine growth lines. Apex angular, apical umbilicus narrow (0.34 mm); umbilicus not observable; anterior end rounded; aperture long, wide anteriorly, narrowing abruptly at about º⁄5 of its length. Outer lip morphology not preserved.

REMARKS

One complete specimen and a second, incomplete specimen of a Pyrunculus species are available. The species is reminiscent of the widespread Miocene Pyrunculus elongatus ( Eichwald, 1830) but differs in its smaller size, more slender outline and the more pronounced concavity in the upper part of the last whorl. Moreover, its apex is wider and straighter than in P. elongatus . Dorsally, the outline forms an almost straight line on the left side, whereas the right side is more angular, with a small angle at about 2/3 of the height of the shell.

The Greek specimens seem to represent a new species, but due to the low number of available specimens and their moderate preservation; we refrain from describing it formally as new.

Figures

FIG. 7. — A1-A3, Mathilda sp., AMPG(IV) 2478; B1, B2, Acteon cf. pinguis d’Orbigny, 1852: B1, AMPG(IV) 2479 (SEM image); B2, AMPG(IV) 2479, detail of microsculpture (SEM image); C1, C2, Ringicula minor (Grateloup, 1838), AMPG(IV) 2488; D1-D3, Retusa truncatula (Bruguière, 1792): D1, D2, AMPG(IV) 2541; D3, AMPG(IV) 2542 (SEM image); E1, E2, Pyrunculus sp., AMPG(IV) 2545; F1, F2, Volvulella acuminata (Bruguière, 1792), AMPG(IV) 2547; G1-G3, Pyramidella cf. plicosa Bronn, 1838: G1, G2, AMPG(IV) 2554; G3, AMPG(IV) 2555 (SEM image); H1-H3, ‘Odostomia’ sp. 1, AMPG(IV) 2557; H3, AMPG(IV) 2557 (SEM image); H4, AMPG(IV) 2557, apex (SEM image). Scale bars: A1-A3, C1, C2, E1, E2, F1, F2, G1, G2, H1, H2, 1 mm; B1, 200 µm; B2, H4, 100 µm; D1, D2, H3, 500 µm; D3, G3, 400 µm.