Rimulopsis danuviensis, Gründel & Nützel, 2024

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

Rimulopsis danuviensis sp. nov.

Plate 2: figs 7, 8

Etymology.

After the river Donau, Latin Danubius.

Holotype.

SNSB–BSPG 2016 XXI 1653 (Plate 2 : fig. 7) (collection Neubauer).

Paratypes.

3 specimens Saal (2 specimens collection Sylla, SNSB–BSPG 2016 XXI 1655 –1656 , 1 specimen collection Neubauer, SNSB–BSPG 2016 XXI 1654 ) .

Type locality and stratum.

Upper Jurassic (Kimmeridgian) reefal limestones from the locality Saal near Kelheim, Lower Bavaria ( Gründel et al. 2015, 2022).

Diagnosis.

Limpet ornamented with a repeated alternation of one strong and 1–3 weaker radial ribs and few bulgy concentric ribs; shell angulated at two of the prominent radial ribs that are nodular at intersections with concentric ribs; several weak concentric ribs are intercalated between two strong concentric ribs.

Description.

Shell limpet-shaped; a shell is 9 mm high; apex strongly bent in posterior direction protruding the posterior shell margin in lateral and dorsal view; selenizone raised, forming crest; lunulae lamellar, concave anteriorly; at each side of selenizone, 1–2 weak and then one strong radial rib; at these strong radial ribs, shell is distinctly angulated; lateral shell sides ornamented with a repeated alternation of one strong and 1–3 weaker radial ribs and few, distantly spaced bulgy concentric ribs; intersections of radial and concentric ribs nodular, nodes especially strong on the two ribs that angulate the shell; in addition, weak concentric, co-marginal ribs are present.

Remarks.

Rimulopsis broesamleni Gründel et al., 2017 has a regularly alternation of a weaker and a stronger radial rib as well as weaker concentric ribs. This produces a cancellate ornament including deep pits demarcated by radial and concentric ribs. Instead of concentric bulgy ribs, it has more regular and defined ribs. Intersections of radial and concentric are only weakly nodular. Rimula etalloni Loriol in Loriol and Bourgeat (1886–1888) sensu Gründel et al. (2020 a) has an alternation of each one stronger and one weaker radial rib; it lacks weaker concentric ribs between the bulgy concentric ribs. Rimulopsis paucicostata (Étallon, 1861 in Thurmann and Étallon) sensu Gründel et al. (2020 a) has an alternation of each, one strong and one weak radial rib; bulgy concentric ribs are confined to the apical portion of the shell whereas weak concentric ribs are present in the abapical portion of the shell.

Figures

Plate 2. (1, 2) Leptomaria sp., SNSB – BSPG 2016 XXI 1628, lateral and basal views, width 30 mm. (3–5) Leptomaria phacoides Zittel, 1873, SNSB – BSPG 2016 XXI 1629, lateral, apical and basal views, width 41 mm. (6) Leptomaria phacoides Zittel, 1873?, SNSB – BSPG 2016 XXI 1631, lateral view, height 22 mm. (7) Rimulopsis danuviensis sp. nov., holotype, SNSB – BSPG 2016 XXI 1653, collection Neubauer, lateral view, height 9 mm. (8) Rimulopsis danuviensis sp. nov., paratype, SNSB – BSPG 2016 XXI 1654, collection Neubauer, anterior view, height 7 mm. (9–11) Asperilla longispina (Rolle, 1861), SNSB – BSPG 2016 XXI 1661, lateral, apical and basal views, width including spines 24 mm. (12, 13) Falsataphrus? valfinense Loriol, in Loriol and Bourgeat (1886–1888), SNSB – BSPG 2016 XXI 1696, apical and lateral views, width 12 mm. (14, 15) Caryomphalus globatus (Buvignier, 1843), SNSB – BSPG 2016 XXI 1713, basal and lateral views, width 15 mm.