Calliostoma, Swainson, 1840

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 : 124-125

Calliostoma ? sp.

Fig. 4D–F

Material examined

ITALY – Tuscany • 1 spec.; Le Colline ; MSF 1208 (W = 7.3 mm) .

Description

Dome-shaped shell, ca 6 mm high, whorls with slightly convex flanks and indistinct suture, sculpture cancellate with 10 spirals on last whorl, crossed by equally sized and spaced, oblique and sinuous axial ribs.

Remarks

The cancellate sculpture and dome-shaped spire of this species are somewhat unusual for Calliostoma , but the specimen is within the morphological range of other Calliostoma species ( Quinn 1992; Dornellas & Simone 2013). Shells with similar sculpture and a general dome-like habitus, though with much broader spire, are built by members of the genus Ancistrobasis Dall, 1889 (i.e., Ortega & Gofas 2019; Gofas et al. 2021).

The shell resembles certain species of Jujubinus Monterosato, 1884 , for example Jujubinus cf. proximus (Millet, 1865) and Jujubinus sceauxensis Landau, Van Dingenen & Ceulemans, 2017 , from the Loire Basin in northwestern France ( Landau et al. 2017: pls 23, 25). But Jujubinus inhabits intertidal to shallow submarine habitats ( Rueda et al. 2008; Reich et al. 2014) and is unlikely to be found in a deep-marine seep environment. Similar sculpture and shell shapes can also be seen in members of the trochoid genus Odontotrochus Fisher, 1879 , for example the extant species Odontotrochus suni Huang & Fu, 2022 and O. poppei (Lan, 1991) from North Australia ( Huang & Fu 2022). The Late Miocene Phorculellus taurangulosus Sacco, 1896 from the Turin hills ( Ferrero Mortara et al. 1984: pl. 48 fig. 1) has similar sculpture but less straight-sided whorls than Calliostoma ? sp.

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).