Class Gastropoda Cuvier, 1795

Family Rissoidae Gray, 1847

Genus Alvania Risso, 1826

Species Alvania calliope Chirli & Linse, 2011

 Alvania calliope Chirli & Linse, 2011

Known only for the Pleistocene (Calabrian) of Rhodes Island (Greece). Nota solo per il Pleistocene inferiore (Calabriano) dell’Isola di Rodi (Grecia).

Gastropoda  Rissoidae  Alvania  Alvania calliope Gastropoda  Rissoidae  Alvania  Alvania calliope

 Description

(O.D.) Shell small, thick, consists of 5 convex whorls separated by impressed sutures. Protoconch with 1.75 whorls, sculptured with 10-12 faint, irregular and tuberculose spiral cords. The cords are separated by wider interspaces. The whorls of the teleoconch are sculptured with 15-16 strong axial ribs, which are moderately opisthocline, getting weaker adapically and are separated by wider interspaces. The spiral sculpture consists of a strong cord near the anterior suture and two weaker cords on the whorl. Last whorl expanded, rounded at the periphery and crossed by four spiral threads. Base convex, delimited by a presutural cord and crossed by four strong concentric cords. Aperture oval, oblique, posteriorly restricted, outer lip varicose. Columellar edge with heavy but restricted callus.

Bibliographic references and some more common synonyms

2011 Alvania calliope – Chirli & Linse, p. 75, pl. 20, figs 2a-e

2021 Alvania calliope – Chirli & Forli, p. 99, pl. 71, figs A1-5

Remarks

The specimens from Kritika and Lardos are of smaller dimensions and the spiral sculpture is weaker, in some specimens only the cord near the anterior suture is present. Notwithstanding the diversities in dimension and sculpture, the protoconchs of the two forms are identical and we exclude any separation also on a subspecific level.

Alvania calliope differs from A. lanciae (Calcara, 1845) because of its more expanded shape, a lower protoconch, sculptured with fainter and more regular spiral threads, the whorls are less convex, the axial ribs smaller in number and the spiral threads less pronounced (Chirli & Linse, 2011, pag. 76)

Stratigraphic distribution

Pleistocene (Calabrian) of Rhodes Island: Kritika, Ladiko, Laerma road and Lardos (Chirli & Linse, 2011).

 References

Chirli C. & Linse U. (2011). The Pleistocene Marine Gastropods of Rhodes Island (Greece). Tavarnelle, The authors. 447 pp.; 90 plates.

Chirli C. & Forli M., (2021). The Family Rissoidae Gray, 1847 from Miocene to Present-day, in the Mediterranean Basin. Edizioni Danaus, Palermo

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Acknowledgements

Si ringrazia l’amico Carlo Chirli (Tavarnelle, Firenze) per la concessione all’uso di alcuni suoi testi. See also Edizioni Danaus