Calliostoma sp.

Kiel, Steffen, Sami, Marco & Taviani, Marco, 2023, Mollusks (Gastropoda, Bivalvia) from Miocene cold-seep deposits in northern Italy: revisions and additions, European Journal of Taxonomy 910, pp. 115-160 : 124

Calliostoma sp.

Fig. 4A–C

Material examined

ITALY – Tuscany • 1 spec.; Le Colline ; MSF 1207 (H = 10 mm) .

Description

Conical shell, about 10 mm high, at least seven straight-sided whorls beaded spiral cords at upper and lower suture, smooth in between; basal margin sharp, base smooth, almost flat; aperture subcircular, entire.

Remarks

Sacco (1896) illustrated various species of Calliostoma (as Ampullotrochus ) from Miocene and Pliocene strata of northern Italy. Similar regarding the nodular subsutural cords are Ampullotrochus cinculatus (Verrill, 1884) ( Sacco 1896: 45, pl. 4 fig. 46) and A. granulatus Born, 1778 ( Sacco 1896: 42–43, pl. 4 figs 34–37). The latter species has, as the name indicates, a more granular sculpture (see Gardella & Tabanelli 2017: figs 3–4). A similar fossil Calliostoma with smooth whorl flanks but less distinct subsutural nodular cords is Calliostoma margarita Lozano-Francisco & Vera-Peláez, 2002 from the Pliocene of southern Spain and northern Italy ( Lozano-Francisco & Vera-Peláez 2002; Gardella & Tabanelli 2017). Similarly high-spired but with more distinct spiral ornament is the Pliocene Ampullotrochus perstriolatus Sacco , re-illustrated by Ferrero Mortara et al. (1984: pl. 49 fig. 5).

Stratigraphic and geographic range

Middle Miocene (lower Serravallian), northern Italy.

Figures

Fig. 4. Calliostomatidae Thiele, 1924 (1847) (Vetigastropoda) from the Calcari a Lucina seep deposits in northern Italy. A–C. Calliostoma sp., Le Colline (MSF 1207). D–F. Calliostoma? sp., Le Colline (MSF 1208).