Diodora graeca (Defrance, 1820)

Diodora graeca (Defrance, 1820) View in CoL

( Fig. 4D View FIG 1 View FIG , D 2 View FIG )

Patella graeca Linnaeus, 1758: 784 .

Diodora graeca View in CoL – Landau et al. 2003: 26, pl. 4, fig. 4; 2017: 80, pl. 3, figs 1-4. — Chirli & Linse 2011: 35, pl. 4, fig. 5. — Ceulemans et al. 2016: 54, pl. 1, figs 5, 6. — Chirli & Forli 2017: 24, fig. 5a.

For more, see synonymy list in Landau et al. (2003, 2017) and Ceulemans et al. (2016).

MATERIAL AND DIMENSIONS. — Maximum height 23.5 mm, diameter 11.9 mm. — RGM.1364899 (3), leg. WG ; RGM.1364964 (7), leg. ACJ ; RGM.1365061 (24), leg. AWJ ; RGM.1365174 (1), leg. AWJ ; RGM.1365062 (1), leg. AWJ .

SPECIES CHARACTERISATION. — Patelliform shell with ovate profile; apical perforation two-third distance from anterior margin; sculpture of primary to tertiary ribs differentiated to a variable degree.

DISTRIBUTION. — Middle Miocene: Paratethys ( Strausz 1966; Bałuk 1975). — Upper Miocene: NW France ( Ceulemans et al. 2016); Proto-Mediterranean ( Sacco 1896a). — Lower Pliocene: NW France ( Ceulemans et al. 2016), Coralline Crag, England (Harmer 1923), Belgium (Marquet & Landau 2006); central Mediterranean ( Chirli 2004). — Upper Pliocene: Red, Crag, England (Harmer 1923); western and central Mediterranean ( Landau et al. 2003; Malatesta 1974; Caprotti 1976; Cavallo & Repetto 1992); France ( Chirli & Richard 2008). — Lower Pleistocene: NW France ( Brébion 1964), Selsoif (this paper); central Mediterranean ( Cerulli-Irelli 1916; Malatesta 1960; Chirli & Forli 2017); eastern Mediterranean, Rhodes Island ( Chirli & Linse 2011). — Upper Pleistocene: England (Harmer 1923), Netherlands ( Wesselingh & Pouwer 2011); western Mediterranean, Balearic Islands ( Cuerda Barceló 1987). Today this species occurs from the Atlantic British Isles to Canaries, Mediterranean and Black Sea on rocky shores under stones and rocks, especially where a little silt occurs, living near sponges, on which it feeds ( Poppe & Goto 1991).

REMARKS

This species is highly variable in height and the differentiation between the primary to tertiary ribs (see discussion in Ceulemans et al. 2016: 55). Some of the Selsoif specimens have weaker primaries than seen in some Mediterranean fossil material.