Ptygmatis? ursicina (Thurmann, 1861 in Thurmann and Etallon 1861-1864)

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? ursicina (Thurmann, 1861 in Thurmann and Etallon 1861-1864)

Plate 12: figs 5-7

?1844 - Nerinea visurgis Röm. - Goldfuss: 44, pl. 176, fig. 6.

1852 - Nerinea visurgis Roemer, 1836 - d’Orbigny: 122, pl. 268, figs 5-7.

*1861-1864 - Nerinea ursicina Th. - Thurmann and Étallon: 103, pl. 8, fig. 50.

?1872 - Nerinea pseudospeciosa P. de Loriol, 1871 - Loriol, Royer and Tombeck: 89, pl. 6, fig. 7.

1889 - Nerinea ursicina Thurmann - Loriol and Koby: 37, pl. 6, figs 1-8.

1898 - Nerinea ursicinensis Thurmann - Cossmann: 37, pl. 3, figs 11, 12.

1927 - Nerinea ursicinensis Thurmann - Maire: 142, pl. 7, figs 15, 16.

1997 - Cossmannea (Eunerinea) ursicina (Thurmann, 1861) - Fischer and Weber: 40, pl. 9, fig. 2.

Material.

Nineteen juvenile specimens from Saal (collection Lang), of which two are illustrated (SNSB-BSPG 2021 XV 30, 31).

Description.

The largest specimen from Saal is 9 mm high. The shell is slender to very slender. The whorls are regularly increasing in width. The whorl face is concave, with a strong, sometimes ramp-like bulge. The bulge is formed at the suture by both whorls. The suture is situated somewhat above the middle of the bulge. The whorl face between the bulges is initially ornamented with one spiral cord, later whorls with 4-5 spiral cords: two of these spiral cords may be stronger than the others. The bulges and stronger spiral cords are possibly nodular (unclear due to preservation). The base is flat, with an almost rectangular transition to the whorl face. The transition has a strong, protruding bulge that is largely covered by the following whorls of the spire. The base is densely covered with weak spiral cords. The aperture has an approximately rectangular outline and distinct oblique siphonal canal. The aperture has a single parietal plait, two columellar plaits, and a palatal plait.

Remarks.

The identity of the present juvenile shells with much larger growing taxa is uncertain (see synonymy list). Thurmann in Thurmann and Étallon (1861-1864) reported that Nerinea ursicina has distinct knobs on the bulges and partly also on the spiral cords between the bulges. Such a knobby ornament could not be substantiated for the present material, due perhaps to preservation.

Relationships.

Differences to Ptygmatis? polyspira (Quenstedt, 1881-1884) are herein discussed in the treatment of this taxon. Nerinea subscalaris Münster in Goldfuss (1844) has higher whorls in relation to whorl width and it has more oblique sutures. Nerinea? lafayettensis Imlay, 1945 has, among other differences, only two spiral cords between the bulges. Nerinea speciosa Voltz sensu Maire (1927) has a broader shell with lower whorls and its bulges are not as much protruding. Nerinea mariae d’Orbigny sensu Cossmann (1898) is slenderer and has higher whorls.

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.