Rissoina subconoidea (Grateloup, 1847)

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 : 338

Rissoina subconoidea (Grateloup, 1847) (Fig. 5 E1, E2)

Rissoa cochlearella var. A subconoidea Grateloup, 1847: 4 , figs 17, 18.

Rissoina subconoidea – Landau et al. 2013: 75, pl. 6, fig. 9 (cum syn.).

MATERIAL EXAMINED. — Sample F10: AMPG ( IV) 2448-2450 (three specimens).

DIMENSIONS. — Maximum height: 1.85 mm (incomplete).

DISTRIBUTION. — Late Oligocene. NE Atlantic: France (Aquitaine Basin) ( Cossmann & Peyrot 1919; Lozouet et al. 2001).

Early Miocene. NE Atlantic: France (Aquitaine Basin) ( Cossmann & Peyrot 1919; Lozouet et al. 2001); Proto-Mediterranean Sea: Greece (Aquitanian, this paper), Italy (Burdigalian, Sacco 1896).

Middle Miocene. NE Atlantic: France (Aquitaine Basin) ( Cossmann & Peyrot 1919); Proto-Mediterranean Sea: Turkey ( Landau et al. 2013); Paratethys: Austria ( Hörnes 1856), Poland ( Bałuk 1975), Hungary ( Strausz 1966).

REMARKS

The species has a characteristic elongated solid shell with slightly opisthocline axial ribs. The subobsolete spiral sculpture of the last whorl mentioned by Landau et al. (2013) is not preserved in our incomplete material.

Lozouet et al. (2001) treated Rissoina podolica Cossmann, 1921 as subjective junior synonym of R. subconoidea (Grateloup, 1847) , which is followed herein.

During the Early Miocene (Aquitanian and Burdigalian) R. subconoidea was relatively widespread in the northeastern Atlantic and the Proto-Mediterranean. According to Ponder (1984), recent Rissoina species take shelter beneath stones and in crevices and feed on foraminifers. Rissoina species live in littoral environments ( Tămaș et al. 2013), they are also known from seagrass-associated gastropod communities ( Harzhauser 2014).

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.