Chemnitzia? lactea ( Linnaeus, 1758 )

Bouchard, Blanche, Wesselingh, Frank P., Pouwer, Ronald & Landau, Bernard, 2025, The Gelasian gastropod fauna of Selsoif (Manche, France), Geodiversitas 47 (3), pp. 39-91 : 79

Chemnitzia? lactea ( Linnaeus, 1758)

( Fig. 14D 1-D 3 )

MATERIAL AND DIMENSIONS. — Maximum height 4.3 mm (incomplete), width 1.5 mm.— RGM.1364932 (1), leg. WG ; RGM.1365023 (68), leg. ACJ ; RGM.794509 (c. 95), leg. AWJ .

SPECIES CHARACTERISATION. — Fragment consisting of last 4.5 whorls, sculptured by broad, curved, opisthocline ribs, wider than their interspaces, stopping abruptly at suprasutural cord and at base.

DISTRIBUTION. — Lower Pleistocene: Atlantic, Selsoif, NW France (this paper).

REMARKS

The character of the spiral sculpture stopping abruptly at a suprasutural cord on the later spire whorls and at the base on the last whorl allows attribution to the genus Chemnitzia d'Orbigny, 1840 (see Landau & Micali 2021: 284). The material resembles the modern highly variable Chemnitzia lactea , but the general worn appearance and the lack of preserved protoconch make attribution uncertain.

Figures

FIG. 14. — 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, Ondina cf. micropeas (Boettger, 1902), RGM.1365213, leg ACJ, H = 2.13 mm; B, Menestho derivata (Wood, 1879), RGM.1365207, leg AWJ, H = 1.56 mm; C, Spiralina alpinoligustica (Sacco, 1892), RGM.1365205, leg AWJ, H = 1.23 mm; D, Chemnitzia?lactea (Linnaeus, 1758), RGM.1364932, leg WG, H = 4.39 mm; E, Turbonilla indet., RGM.1365305, leg AWJ, H = 1.32 mm; F, Chrysallida indet., RGM.1365324, leg AWJ, H = 1.12 mm; G, “Ellobium” pyramidale (J. de C. Sowerby, 1822), RGM.1365208, leg AWJ, H = 13 mm. Scale bars: A-C, E, F, 1 mm; D, 2 mm; G, 5mm.

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).