Ptygmatis clio ( d'Orbigny , 1852)

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

Ptygmatis clio ( d'Orbigny, 1852)

Plate 12: figs 1-3

*1852 - Nerinea clio d’Orbigny - d’Orbigny: 139, pl. 275, figs 3-5.

1886-1888 - Ptygmatis clio d’Orbigny - Loriol in Loriol and Bourgeat: 84, pl. 7, figs 1-3.

1898 - Ptygmatis clio d’Orbigny - Cossmann: 72, pl. 6, figs 18, 19.

1997 - Polyptyxisella clio ( d’Orbigny, 1852) - Fischer and Weber: 55, pl. 12, figs 9, 10.

Material.

Two illustrated specimens (SNSB-BSPG 2021 XV 59, 60) and a questionable one, all from Saal, collection Lang.

Description.

The largest specimen (Plate 12 : fig. 3) is 108 mm high. The shell is slender. The whorl face is straight. The last whorl of the largest specimen has a weak, indistinctly delimited subsutural furrow. The sutures are distinct. The whorls lack visible ornament. The basal edge is pronounced and forms an angular transition to the base. The base is incompletely preserved, and is seemingly smooth with a distinct umbilicus. The aperture is not preserved. A columellar section shows the presence of a parietal, two columellar, and one palatal plaits.

Remarks.

Fischer and Weber (1997) designated a lectotype (section of a shell, Fischer and Weber 1997: pl. 12, fig. 9) that agrees well with the sectioned shell illustrated herein (Plate 12 : figs 1, 2). The lateral view provided by Fischer and Weber (1997: pl. 12, fig. 10) also agrees well with the present material. The specimens illustrated by Fischer and Weber (1997) are from the middle Oxfordian of St. Mihiel, but these authors noted that the species is also present in the Kimmeridgian. The illustration given by d’Orbigny (1852: pl. 275, figs 3-5) deviates more strongly from our specimens: the shell is slenderer and the whorl face is distinctly concave.

Relationships.

Aptyxiella planata (Quenstedt) sensu Hägele (1997), A. quenstedti Geiger, 1901, and A. ewaldi Geiger, 1901 lack plaits. Cossmannea nantuacensis ( d’Orbigny) sensu Fischer and Weber (1997) is much larger, lacks an umbilicus and columellar and parietal plaits. Megaptyxis caucasica Pchelintsev, 1965 has a concave whorl face and more oblique sutures.

Figures

Plate 12. (1 - 3) Ptygmatis clio (d'Orbigny, 1852). (1 - 2) SNSB-BSPG 2021 XV 59, Saal (collection Lang); (1) section of fragment, height 21 mm; (2) detail, height 3.7 mm. (3) SNSB-BSPG 2021 XV 60, Saal (collection Lang), lateral view, height 108 mm. (4) Ptygmatis? polyspira (Quenstedt, 1881 - 1884), holotype, collection University Tuebingen (collection Quenstedt); Nattheim, lateral view, height 32 mm (original to Quenstedt 1881 - 1884, pl. 207, fig. 3. (11 - 12) Bactroptyxis teres (Muenster in Goldfuss, 1844), collection Sauerborn, Nattheim area. (5 - 7) Ptygmatis? ursicina (Thurmann in Thurmann & Etallon, 1861). (5 - 6) SNSB-BSPG 2021 XV 30, Saal (collection Lang); (5) last whorl with aperture, height 4 mm; (6) lateral view, height 9.5 mm. (7) SNSB-BSPG 2021 XV 31, Saal (collection Lang), aperture and ornament of base, width 2.5 mm.