Lacuna pallidula ( da Costa, 1778 )

Bouchard, Blanche, Wesselingh, Frank P., Pouwer, Ronald & Landau, Bernard, 2025, The Gelasian gastropod fauna of Selsoif (Manche, France), Geodiversitas 47 (3), pp. 39-91 : 56

Lacuna pallidula ( da Costa, 1778)

( Fig. 7D 1-D 3 )

Cochlea pallidula da Costa, 1778: 51, pl. 4, figs 4, 5.

Lacuna pallidula – Harmer 1921: 665, pl. 53, fig. 25. — Fretter & Graham 1980: 250, figs 201-202. — Strand Petersen 2004: 29, fig. 7. — Moerdijk & Janse 2015: 23, fig. 11.

MATERIAL AND DIMENSIONS. — Maximum height 4.7 mm, width 5.1 mm. RGM.1364981 (20), leg. ACJ ; RGM.1365182 (1), leg. AWJ ; RGM.1364913 (2), leg. WG ; RGM.1365081 (51), leg. AWJ .

SPECIES CHARACTERISATION. — Small, round shell. Three smooth teleoconch whorls; spire almost flat; last whorl 92% of the total height. Prosocline growthlines. Aperture round; moderately extent columella fold on an open umbilicus.

DISTRIBUTION. — Lower Pleistocene: Scotland and Ireland ( Harmer 1921); Atlantic, Selsoif, NW France (this paper). — Holocene: NSB ( Strand Petersen 2004). Today this is predominantly a northern species extending from south of the Arctic Circle on the American coast from Greenland to Connecticut ( Gould 1840; Trott 2004), in the eastern Atlantic the distribution extends from the White Sea ( Vortsepneva et al. 2023), North Sea ( Dumoulin 1989), British Isles ( Fretter & Graham 1980; Guiry & Guiry 2011), France ( Müller 2004) into northern Spain ( Rolán 1983). The species is associated with Fucus serratus ( Smith 1973) .

Figures

FIG. 7. — Gastropods from Selsoif. All illustrated specimens are collected from the Sablière du Grand Marais,Selsoif,France and come from the Early Pleistocene Saint-Nicolas de Pierrepont Formation (continuation): A, Boreoscala similis (J. de C. Sowerby, 1813), RGM.1365181, leg WG, H = 6.5 mm; B, Boreoscala similis (J. de C. Sowerby, 1813), RGM.1364911, leg WG, H = 9.3 mm; C, Lacuna crassior (Montagu, 1803), RGM.1365195, leg WG, H = 3.5 mm; D, Lacuna pallidula (da Costa, 1778), RGM.1365182, leg AWJ, H = 2.1 mm; E, Lacuna parva (da Costa, 1778), RGM.1365183, leg ACJ, H = 2 mm; F, Lacuna cf. vincta (Montagu, 1803), RGM.1364982, leg ACJ, H = 1.9 mm; G, Littorina obtusata (Linnaeus, 1758), RGM.1365211, leg ACJ, H = 2.3 mm; H, Littorina obtusata (Linnaeus, 1758), RGM.1310829,leg WG,H = 8.4 mm;I, Littorina littorea (Linnaeus,1758),RGM.1365070,leg AWJ,H = 6 mm;J, Littorina littorea (Linnaeus,1758),RGM.1365202A, leg AWJ, H = 3.02 mm. Scale bars: A, B, 2 mm; C, J, 1 mm; D-G, 500 μm; H, 5 mm; I, 2 mm.

FIG. 1. — Simplified geological map of the Normandy region (after Dugué et al. 2000 and Pareyn 1987) showing the location of Selsoif:1, Precambrian-Palaeozoic basement; 2, Permo-Mesozoic Paris Basin fill; 3, Neogene-Quaternary subbasins.

FIG. 3. — Simplified biographic map of South-West of Europe (after Landau et al. 2011).