Menestho derivata ( Wood, 1879 )

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

Menestho derivata ( Wood, 1879)

( Fig. 14B 1-B 3 )

Odostomia derivata Wood, 1879: 39 , unnumbered text-fig. p. 40.

Menestho derivata – Harmer 1920: 583, p. 583, pl. 50, fig. 4.

MATERIAL AND DIMENSIONS. — Maximum height 1.6 mm, width 0.8 mm. — RGM.1365207 (1), leg. AWJ.

SPECIES CHARACTERISATION. — Shell fusiform. Protoconch type C. Teleoconch of 3.5 convex whorls separated by narrowly impressed suture. Sculpture consist of numerous spiral cords, broader than their interspaces, six on first teleoconch whorl, 18 on last whorl. Last whorl 70% of the total height. Aperture pyriform; outer lip not complete; columella without fold.

DISTRIBUTION. — Lower Pleistocene: NSB, England ( Wood 1879; Harmer 1920); Atlantic, Selsoif, NW France (this paper).

REMARKS We tentatively ascribe the specimen to Menestho derivata ( Wood, 1879) , described from the Lower Pleistocene Bramerton Crag (= Norwich Crag) of England. It is similar in sculpture to two extant northern European species: Menestho albula (Fabricius, 1780) and M. truncatula Odhner, 1915 , but both of these species are squatter with more convex whorls.

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).