Eunerinea sp. 1

Gründel, Joachim & Nützel, Alexander, 2024, Late Jurassic (Upper Kimmeridgian) gastropods from Saal near Kelheim (Germany, Bavaria), Zitteliana 98, pp. 19-72 : 19-72

Eunerinea sp. 1

Plate 14: figs 1–6

? 1861–1864 – Nerinea speciosa Voltz – Thurmann in Thurmann and Étallon: 104, pl. 8, fig. 51.

part 1997 – Nerinella cf. laufonensis (Thurmann, 1859) – Hägele: 131, fig. on p. 131 upper middle (not upper right).

? 1997 – Nerinella caecilia (d’Orbigny, 1852) – Fischer and Weber: 52, pl. 8, figs 1–2.

2022 – Gen. et sp. indet. – Gründel, Keupp, Lang and Nützel: 212, pl. 19, figs 9–11.

Material.

20 specimens from Saal and 2 specimens from Saal, location 2, illustrated specimens SNSB-BSPG 2016 XXI 1923 –1925.

Description.

Only fragments are present; fragment shown on Plate 14 : figs 2, 3 is 34 mm high; shell slender; whorl face straight to slightly concave; subsutural nodular bulge; strength of bulge and nodes vary from distinct to almost absent; a specimen from the collection Lang (Plate 14 : fig. 1) has very distinct nodes that are axially elongated and opisthocline; some specimens with distinct knobby spiral cord between subsutural bulge and abapical suture as well as one (or several?) weak, knobby spiral cords on either side of it; other specimens have only two weak knobby spiral cords of approximately equal strength; transition from whorl face to slightly convex base at slightly protruding edge that forms periphery of whorls; edge has strong strong nodes, some of which visible above suture; several knobby spiral cords cover base; late whorls of large specimens have blurred axial ribs on whorl face and base; base phaneromphalous; aperture with abapical canal; at least one columellar and one (or two?) parietal plaits present in aperture.

Remarks.

The few available specimens are mainly poorly preserved and show quite some variation. A comparison of Plate 14 : fig. 1 with Plate 14 : figs 2, 3 shows two extreme morphotypes. However, most of the fragments cannot be assigned to one of these morphotypes with certainty because of insufficient preservation. It is also not certain whether these morphologies grade into each other. The grouping of the present material under the name Eunerinea sp. 1 is based on similarities in the general shell shape and the basic shell ornament, the occurrence at the same locality and in the same stratigraphic level. It remains unclear whether there is one variable species or two separate species. Several species described in the literature resemble either one or the other mentioned morphotype.

The neotype of Nerinella caecilia (d’Orbigny) (see Fischer and Weber 1997) closely resembles the present species, but apparently has more numerous spiral cords on the whorl face and lacks a subsutural row of nodes. The whorls are at least partially more concave. Nerinella subimbricata d’Orbigny, 1852 sensu Fischer and Weber (1997) is significantly more slender and the whorl face is more concave. Ptygmatis nodosa ( Voltz, 1836) sensu Gründel et al. (2022) has, among other differences, a border spiral cord without nodes. Nerinea sequana Thirr sensu Bronn (1836) is more slender and the whorls are concave. Nerinea laufonensis Thurmann in Thurmann and Étallon 1861 lacks a subsutural row of nodes, the border spiral rib is hardly knobby and, in addition to two rows of nodes, several lirae are formed on the whorl face. Nerinea oppeli Gemmellaro, 1870 is similar to the specimen shown in Plate 14 : fig. 1, but the subsutural row of nodes is weaker, whereas the nodes of the border spiral cord are stronger and are fully visible above the suture. Nerinea cf. heightneggeri Peters sensu Cossmann (1898) is more slender and has 7–8 spiral cords on the whorl face, two of which are tuberculate.

Figures

Plate 14. (1) Eunerinea sp. 1, SNSB BSPG 2021 XV 92, lateral view, height 19 mm. (2, 3) Eunerinea sp. 1, SNSB-BSPG 2016 XXI 1923, lateral and basal view, height 33 mm, width 16 mm. (4, 5) Eunerinea sp. 1, SNSB-BSPG 2016 XXI 1924, (4) lateral view, height 34 mm, (5) last two whorls height 21 mm. (6) Eunerinea sp. 1, SNSB-BSPG 2016 XXI 1925, fragment of a single whorl in lateral view, height 34 mm. (7) Eunerinea sp. 2, SNSB-BSPG 2016 XXI 1926, fragment of a single whorl in lateral view, width 16 mm. (8) Eunerinea sp. 2, SNSB-BSPG 2016 XXI 1927, lateral view, height 38 mm. (9–11) Itieria cabanetiana (d’Orbigny, 1841), SNSB-BSPG 2016 XXI 1928, lateral views, height 67 mm, basal view, width 41 mm. (12, 13) Itieroptygmatis cylindrata Gründel et al., 2022, morphotype 2, SNSB-BSPG 2016 XXI 1929, lateral views, height 24 mm.