Pseudorhytidopilus? quadratus, 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

Pseudorhytidopilus? quadratus sp. nov.

Plate 1: figs 9–11

Etymology.

Latin quadratus – due to the quadratic outline of the shell.

Holotype.

SNSB–BSPG 2016 XXI 1607 (Plate 1 : figs 9–10).

Paratypes.

6 specimens SNSB–BSPG 2016 XXI 1608 –1613.

Diagnosis.

Shell thin, with trapezoidal to subquadratic outline with rounded edges in dorsal view; apex approximately in central position; shell ornamented with irregular concentric bulges.

Type locality and stratum.

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

Description.

Large specimen has a diameter of 21 mm; shell very thin, shallowly cap-shaped in lateral view; trapezoidal (one side of shell slightly narrower than the other side) to subquadratic outline with rounded edges in dorsal view; apex approximately in central position; shell ornamented with irregular concentric bulges.

Remarks.

Species with a similar ornament of bulges (e. g., P.? ledonii ( Haber, 1932) sensu Gatto and Monari 2010, Fabercapulus semisculptus Monari et al. 2017 ) have an elliptic outline in dorsal view and a radial furrow. Other species with an oval outline in dorsal view lack a furrow and an ornament of bulges ( P. latissima (Sowerby, 1816) sensu Munt in Martill and Etches 2020, Berlieria maeotis (Eichwald) sensu Gerasimov, 1992 and others).

Brunonia annulata (Yokoyama, 1890) from the Cretaceous of Japan is also cap-shaped and has a similar ornament but its type species is much larger and has a rounded, oval outline in dorsal view ( Kase 1988; Dieni 1990). Patella (Helcion) sculptilis Zittel, 1873 has a straight shell end in lateral view, weak concentric wrinkles and numerous radial ribs.

Figures

Plate 1. (1) Patella sp., SNSB – BSPG 2016 XXI 1601, collection O. Neubauer, dorsal view, length 7 mm. (2–4) Scurriopsis cragolis sp. nov. holotype, SNSB – BSPG 2016 XXI 1602, (2–3) lateral and dorsal views, length 16 mm, (4) detail of ornament, height ca. 5.8 mm. (5–8) Scurriopsis sp., SNSB – BSPG 2016 XXI 1606, (5) dorsal view, length 8 mm, (6) detail in dorsal view, width 3.5 mm, (7–8) lateral view and detail of ornament, height 6 mm. (9–10) Pseudorhytidopilus? quadratus sp. nov., holotype, SNSB – BSPG 2016 XXI 1607, dorsal and lateral views, largest diameter 21 mm. (11) Pseudorhytidopilus? quadratus sp. nov., paratype, SNSB – BSPG 2016 XXI 1608, dorsal view, largest diameter 16 mm. (12) Leptomaria goldfussi (Sieberer, 1907), SNSB – BSPG 2016 XXI 1616, lateral view, height 25 mm. (13, 14) Leptomaria goldfussi (Sieberer, 1907), SNSB – BSPG 2016 XXI 1617, early whorls and detail of ornament, (13) height 16.5 mm, (14) height 14 mm. (15, 16) Leptomaria goldfussi (Sieberer, 1907), SNSB – BSPG 2016 XXI 1618, aperture and base, width 24 mm.