Neuburgensia angulata, 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

Neuburgensia angulata sp. nov.

Plate 9 : fig. 19, Plate 10: figs 1–6

2017 Nerineoidea Nr. 4 – Gründel: 33, pl. 14, fig. A.

Etymology.

Latin angulata – angular; after the angular transition from whorl face to the flat base.

Holotype.

SNSB-BSPG 2016 XXI 1849 (Plate 10 : fig. 1, collection Lang).

Material.

Holotype and 52 paratypes (mainly fragments of various ontogenetic stages): SNSB-BSPG 2016 XXI 1848 , 1850–1855, 1932–1976; most from the collection Sylla, others from collections Keupp, Schäfer, and Neubauer, all from Saal.

Type locality and stratum.

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

Diagnosis.

Shell very slender; whorl face with subsutural nodular bulge, also on late whorls; shell flanks straight; whorl face straight to slightly concave; base flat, set off from whorl face by sharp clear edge at an almost right angle.

Description.

Shell high-spired, slender with numerous whorls; a specimen is 24 mm high; shell flanks straight; whorls significantly wider than high; as far as the fragmentary material can be seen, the early shell has a larger spire angle than later shell; whorl face of early whorls straight with distinct sutures; then, gradual development of subsutural knobby ridge (bulge) demarcating ramp; knobs limited to outer edge of the ramp, only occasionally visible, usually not preserved; ramp usually narrow, occasionally significantly widened and concave; outer whorl face of mature whorls straight to slightly concave; spiral sculpture not recognizable; base flat, set off from whorl face by sharp clear edge at an almost right angle; base without recognizable sculpture; aperture rounded-rectangular, with very clear, backward curved abapical canal; damaged specimens show that the columella axis is hollow.

Remarks.

For, the differences to Neuburgensia rara n. sp. see below. Gymnocerithium ? convexoconcavum Gründel et al., 2019 (also from the Saal quarry) differs in having a convex whorl face in mature whorls as well as a subsutural concavity and the transitions from whorl face to base is evenly rounded. Neuburgensia perrotunda ( Cossmann, 1913) sensu Loriol in Loriol and Koby 1889 in the sense of Gründel et al. (2022) and Cerithium valfinense Loriol in Loriol and Bourgeat 1886–1888 lack a subsutural bulge and the transition from whorl face to base is rounded. Proceritella infragranulata Janicke, 1966 has an angulated transition from whorl face to base and a slightly convex base, the suture lies on a ridge formed by two adjacent whorls, and the whorls increase in width more quickly.

Figures

Plate 9. (1, 2) Ditretus sp., cf. rostellaria (Buvignier, 1852), SNSB SNSB-BSPG 2016 XXI 1808, (1) lateral view, height 25 mm, (2) detail of ornament, height 12 mm. (3, 4) Ditretus sp., cf. rostellaria (Buvignier, 1852), SNSB-BSPG 2016 XXI 1809, lateral views, height 23 mm. (5) Cryptoptyxis? spinosus sp. nov., holotype, SSNSB-BSPG 2016 XXI 1824, apertural and abapertural lateral views, height 22 mm. (6, 7) Coninoda strekwera Gründel, Keupp & Lang, 2019, SNSB-BSPG 2016 XXI 1827, lateral view and longitudinal section, height 33 mm. (8, 9) Tropacerithium cumaritum Gründel, Keupp & Lang, 2019, SNSB-BSPG 2016 XXI 1830, (8) detail of last whorl, height 4 mm, (9) lateral view, height 7 mm. (10–12) Exelissa? aff. corallense (Buvignier, 1843), SNSB-BSPG 2016 XXI 1835, locality 1985, above coral stock, level 2 (“ Fundort 1985, über Korallenstock, Sohle 2 ”), (10) lateral view, height 12 mm, (11) apex in lateral view, height 5 mm, (12) last two whorls in lateral view, height 7 mm. (13, 14) Exelissa ursicina (Loriol in Loriol and Koby 1889), SNSB-BSPG 2016 XXI 1836, (13) l ateral view, height 10 mm, (14) basal view, width 4.5 mm. (15–17) Turritella lucagrita sp. nov., holotype, SNSB-BSPG 2016 XXI 1840, (15) lateral view, height 75 mm, (16) earliest preserved whorls in lateral view, height 40 mm, (17) last whorls in lateral view, height 46 mm. (18) Nudivagus? sp. 2, SNSB-BSPG 2016 XXI 1844, lateral view, height 35 mm. (19) Neuburgensia angulata sp. nov., paratype, SNSB-BSPG 2016 XXI 1848, collection Lang, last whorl with aperture, height 6 mm.

Plate 10. (1) Neuburgensia angulata sp. nov., holotype, SNSB-BSPG 2016 XXI 1849, collection Lang, lateral view, height 24 mm. (2–3) Neuburgensia angulata sp. nov., paratype, SNSB-BSPG 2016 XXI 1850, collection Lang, (2) earliest preserved whorls in lateral view, height 1 mm, (3) lateral view, height 6 mm. (4) Neuburgensia angulata sp. nov., paratype, SNSB-BSPG 2016 XXI 1851, collection Lang, lateral view, height 10 mm. (5) Neuburgensia angulata sp. nov., paratype, SNSB-BSPG 2016 XXI 1852, collection Schäfer ¸ basal view, width 6 mm. (6) Neuburgensia angulata sp. nov., paratype, SNSB-BSPG 2016 XXI 1853, collection Lang, oblique apical, width 6.5 mm. (7–9) Neuburgensia rara sp. nov., holotype, SNSB-BSPG 2016 XXI 1856, (7) lateral view, height 30 mm, (8) early whorls in lateral view, height ca. 7 mm, (9) middle whorls in lateral view, height 12 mm. (10, 11) Purpuroidea lapierrea (Buvignier, 1843), SNSB-BSPG 2016 XXI 1857, lateral and oblique views, height 30 mm. (12, 13) Columbellaria corallina (Quenstedt, 1852), SNSB-BSPG 2016 XXI 1859, (12) apex in lateral view, height 10 mm, (13) lateral view, height 19 mm. (14, 15) Columbellaria corallina (Quenstedt, 1852), SNSB 1860, lateral and slightly oblique lateral views, height 21 mm. (16) Diarthema aspera sp. nov., paratype, SNSB-BSPG 2016 XXI 1862, lateral view, height 44 mm.