Ptygmatis nodosa (Voltz, 1836)

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 nodosa (Voltz, 1836)

Plate 11: figs 1-15

*1836 - Nerinea nodosa (Voltz) - Voltz: 542.

1836 - Nerinea nodosa Voltz - Bronn: 561, pl. 16, fig. 9.

1851 - Nerinea nodosa Voltz - d’Orbigny: 95, pl. 254, figs 3-5.

*1852 - Nerinea calypso d’Orbigny - d’Orbigny: 136, pl. 274, figs 4-6.

*1852 - Nerinea elegans Thurm. - d’Orbigny: 146, pl. 278, figs 4-6.

?1870 - Nerinea plassenensis Pet. - Gemmellaro: 25, pl. 4, figs 14, 15.

1889 - Nerinea nodosa Voltz - Loriol in Loriol and Koby: 32, pl. 4, figs 5-11.

1997 - Ptygmatis nodosa (Bronn ex Voltz, 1836) - Fischer and Weber: 37, pl. 11, figs 4-6.

1997 - Ptygmatis nodosa (Bronn ex Voltz, 1836) - Fischer and Weber: 54.

?1997 - Nerinella elegans (Bronn ex Thurmann, 1836) - Fischer and Weber: 58, pl. 8, fig. 5.

2017 - Nerineoidea Nr. 8 - Gründel: 33, pl.15A.

Material.

142 fragments and juvenile specimens from Saal: 138 specimens collection Lang, of which eight are illustrated (SNSB-BSPG 2021 XV 40-45, 47, 48), four specimens collection Keupp (SNSB-BSPG 2021 XV 46, 49-51).

Description.

The present material consists of fragments of larger specimens and juvenile specimens. The largest specimen is 32 mm high. The apical whorls are not preserved. The shell is slender with a somewhat variable apical angle. The ornament consists of a nodular adapical bulge forming a narrow ramp. The suture is situated on the adapical portion of the bulge. The nodular spiral cord (in some specimens only very weakly developed) is mostly close to the abapical suture or - more rarely - about half way between adapical bulge and abapical suture. The number of nodes per whorl is strongly variable (only in part due to preservation). In few specimens, an additional weakly nodular spiral cord is present between the nodular spiral cord and the adapical bulge. The base is weakly convex with a pronounced spiral cord at the almost rectangular transition to the whorl face. This bordering spiral cord is sometimes nodular. The base is covered with spiral cords. The aperture has a rhomboid outline and a distinctly oblique siphonal canal. The plait pattern is only visible in few specimens. It consists of one or two columellar plaits, one strong parietal plait, while a palatal is plait very rarely visible - perhaps due to the preservation.

Remarks.

In the present material, some specimens have one and others have two columellar plaits. The references listed in the chresonymy and synonymy list above probably refer to material from older strata (Oxfordian, with the exception of Gründel 2017). These references note the presence of four plaits (two columellar plaits, one parietal and one palatal plait).

Relationships.

See Remarks for Eunerinea sp. 1 for relationships with Ptygmatis nodosa . Ptygmatis nodosa Voltz sensu Cossmann (1898) has higher whorls, its whorl face is more concave, its basal spiral rib is not as pronounced and widened, and it has three spiral cords on the base. Nerinea danubiensis Zittel sensu Schlosser (1882) has more rapidly increasing whorls in width, its second nodular spiral cord is situated directly above the suture and forms the basal spiral cord at the transition from whorl face to base instead of having a non-nodular bulge/cord at this position. Moreover, this spiral cord is stronger than the subsutural row of knobs. Nerinea plassenensis Peters, 1855 has a more convex base and stronger subsutural knobs and therefore a more concave whorl face. In Nerinea nodosa Voltz sensu Thurmann and Étallon (1861-1864), the spiral cord at the transition from whorl face to base is distinctly knobby. Ptygmatis nodosa Voltz sensu Maire (1913, 1927) has fewer but larger subsutural knobs, the edge from whorl face to base is at least partly knobby (Maire emphasized the great variability of this species), and it has some spiral cords on the base. Nerinea paronae Stefano, 1884 has more and smaller subsutural knobs, more weak, knobby spiral cord on the whorl face, knobs on the edge demarcating whorl face and base and it has spiral cords on the base.

Figures

Plate 11. Ptygmatis nodosa (Voltz, 1836). (1 - 3) SNSB-BSPG 2021 XV 40, Saal (collection Lang); (1) lateral view, height 22 mm; (2) last whorl with aperture, width 6.6 mm; (3) base, width 6.6 mm. (4 - 5) SNSB-BSPG 2021 XV 41; Saal (collection Lang); (4) lateral view, height 9 mm; (5) base, width 3.5 mm. (6) SNSB-BSPG 2021 XV 42, Saal (collection Lang), aperture, width of whorl 3.7 mm. (7 - 8) SNSB-BSPG 2021 XV 43, Saal (collection Lang); (7) lateral view, height 11.5 mm; (8) last two whorls in lateral view, width 4.2 mm. (9) SNSB-BSPG 2021 XV 44, Saal (collection Lang), base, width 6 mm. (10 - 11) SNSB-BSPG 2021 XV 45, Saal (collection Lang); (10) lateral view, height 16 mm; (11) last whorls in lateral view, width 5.2 mm. (12 - 13) SNSB-BSPG 2021 XV 46, Saal (collection Keupp); (12) lateral view, height 9 mm; (13) apex in lateral view, height 2.9 mm. (14) SNSB-BSPG 2021 XV 47, Saal (collection Lang), lateral view, height 10 mm. (15) SNSB-BSPG 2021 XV 48, Saal (collection Lang), last whorls with aperture, width 7.8 mm.