Alvania transiens (Sacco, 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 : 340-341

Alvania transiens (Sacco, 1895)

(Fig. 5 H1-H4)

Alvania (Acinopsis) sculpta ? var. transiens Sacco, 1895b: 27 .

Alvania (Alvania) transiens – Tămaș et al. 2013: 61 , fig. 2i.

Alvania transiens – Landau et al. 2013: 73, pl. 6, fig. 8 (cum syn.).

MATERIAL EXAMINED. — Sample F11: AMPG ( IV) 2455-2459 (five specimens).

DIMENSIONS. — Maximum height: 3.25 mm.

DISTRIBUTION. — Early Miocene. Aquitanian. Proto-Mediterranean Sea: Greece (this paper); Paratethys: Austria ( Landau et al. 2013). — Burdigalian. Proto-Mediterranean: Italy ( Sacco 1895b).

Middle Miocene. Proto-Mediterranean Sea: Turkey ( Landau et al. 2013); Paratethys: Austria (Cossmann 1921; Kowalke & Harzhauser 2004), Hungary ( Strausz 1966), Poland ( Bałuk 1975), Romania ( Tămaș et al. 2013).

Late Miocene. Proto-Mediterranean Sea: Italy ( Sacco 1895b).

Early Pliocene. central Mediterranean: Italy ( Sacco 1895b).

DESCRIPTION

Shell elongated; protoconch conical, of 2.5 slightly inflated whorls. Four rather flat teleoconch whorls with reticulated sculpture of 9-10 axial ribs and 5 regularly spaced spiral cords, third cord significantly weaker. Base with 5 spiral cords, axial sculpture intersects the 3 first spiral cords thus maintaining the reticulated aspect; 2 spiral cords thick and prominent. Aperture tear-drop shaped; no umbilicus, inner lip smooth, outer lip missing in all specimens.

REMARKS

Very characteristic species, due to its particular sculpture, elongated shape and conical protoconch. The early Miocene Alvania venus (d’Orbigny, 1852) is slightly reminiscent of A. transiens due to its prominent, reticulated sculpture. Kowalke & Harzhauser (2004) discussed the relationship between A. transiens and A. venus; Landau et al. (2013) presented a full list of synonymy which also illustrated the similarities of the two species. Another species with distinct cancellate sculpture is Alvania falsivenus Lozouet, 2015 from the Early Oligocene of SW France ( Lozouet 2015). It differs from the present species in having a less elongate protoconch and shell, and a less pronounced sculpture in early teleoconch whorls.

Superorder LATROGASTROPODA Bouchet et al. 2017 Superfamily CYPRAEOIDEA Rafinesque, 1815

Figures

FIG. 5. — A1, A2, Nodiscala cf. rugatina de Boury in Cossmann, 1912: A1, A2, AMPG(IV) 2335; B1, B2, Triphora (s.l.) sp.: B1, AMPG(IV) 2439 (SEM image); B2, AMPG(IV) 2439, protoconch (SEM image); C1-C4, Metaxia sp.: C1, AMPG(IV) 2443, protoconch (SEM image); C2, AMPG(IV) 2443 (SEM image); C3, C4, AMPG(IV) 2443; D1-D3, Dizoniopsis sp.: D1, D2, AMPG(IV) 2445; D3, AMPG(IV) 2446 (SEM image); E1, E2, Rissoina subconoidea (Grateloup, 1847); E1, E2, AMPG(IV) 2448; F1, F2, Zebinella sp., AMPG(IV) 2451; G1-G4, Alvania amphitrite n. sp.: G1, G2, holotype, AMPG(IV) 1503; G3, paratype 2, AMPG(IV) 1505 (SEM image); G4, paratype 2, AMPG(IV) 1505, protoconch (SEM image); H1-H4, Alvania transiens (Sacco, 1895): H1, H2, AMPG(IV) 2455; H3, AMPG(IV) 2456 (SEM image); H4, AMPG(IV) 2456, protoconch (SEM image); I1, I2, Xenophora sp., AMPG(IV) 2461. Scale bars: A,D1-D3, F1, F2, G1, G2, H1-H3, 1 mm; B1, C2-C4,E1, E2, G3,500 µm; B2, H4, 400 µm; C1, G4, 200 µm; I1, I2, 2 mm.