Ceritellopsis gramanni Huckriede, 1967

Gruendel, Joachim, Keupp, Helmut, Lang, Fritz & Nuetzel, Alexander, 2022, Late Jurassic (Upper Kimmeridgian) Heterobranchia (Gastropoda) of the coral-facies of Saal near Kelheim and the viciniy of Nattheim (Germany), Zitteliana 96, pp. 179-221 : 179

Ceritellopsis gramanni Huckriede, 1967

Plate 3: figs 1-4

?1895 - Ceritella plicata Zittel and Goubert - Cossmann: 102, pl. 4, figs 66, 67.

*1967 - Ceritella (Ceritellopsis) gramanni sp. nov. - Huckriede: 198, pl. 19, figs 4-9.

Material.

Twenty-five specimens from Saal (collection Lang), three of which are illustrated herein: SNSB-BSPG 2021 XV 2-4.

Description.

A large specimen is 3.2 mm high. The shell is fusiform, relatively slender with a high spire. The whorls are rather high and have a distinct, oblique ramp, demarcated from whorl face by a spiral cord. The whorl face is straight. The suture is distinct and is accentuated by the ramp. The whorls are ornamented with straight, slightly opisthocline, rounded axial ribs separated by wide interspaces. The ribs become weaker and may fade entirely on the last preserved whorl. The transition from whorl face to base is evenly rounded. The ribs do not continue onto the smooth base. The aperture is oval, higher than wide, with a weak, short canal and an acute posterior part. The inner lip is reflexed in the columellar portion.

Remarks.

Most of the specimens of Ceritellopsis gramanni figured by Huckriede (1967) have a broader shell. However, in general the present specimens fall into the variation of this species as reported by Huckriede (1967: figs 7 and 8 on pl. 19).

Relationships.

The differences to Ceritellopsis plicatula are discussed under the treatment of that species. Actaeonina plicata Zittel & Goubert, 1861 has a broader, stouter shell and its spire is not as slender and with a lower whorl face of the spire whorls. Ceritella rissoides Buvignier sensu Cossmann (1895) has a broader shell, its last whorl is higher in relation to the spire height and its ramp is not as sharply demarcated. Cerithium lorteti Loriol sensu Loriol and Pellat (1874) has more axial ribs, the whorl face of the spire whorls is higher and the aperture is narrower. Ceritellopsis huckriedei Gründel & Kaim, 2006 is slenderer, its spire is distinctly higher than the last whorl, and it has more axial ribs bent backwards adapically.

Figures

Plate 3. (1 - 4) Ceritellopsis gramanni Huckriede, 1967. (1) SNSB-BSPG 2021 XV 2, Saal (collection Lang), lateral view, height 2.5 mm. (2, 4) SNSB-BSPG 2021 XV 3, Saal (collection Lang); (2) lateral view, height 2.7 mm; (4) base, width 1.3 mm. (3) SNSB-BSPG 2021 XV 4; Saal (collection Lang), aperture, height of detail 1.3 mm. (5 - 6) Ceritellopsis plicatula Huckriede, 1967. (5) SNSB-BSPG 2021 XV 5, Saal (collection Lang), lateral view, height 3.3 mm. (6) SNSB-BSPG 2021 XV 6, Saal (collection Lang), lateral view, height 4.8 mm.