Turritella lucagrita, 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

Turritella lucagrita sp. nov.

Plate 9: figs 15–17

Etymology.

Arbitrary.

Holotype.

SNSB-BSPG 2016 XXI 1840 , the only specimens at hand.

Type locality and stratum.

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

Diagnosis.

Shell high-spired, very slender; whorls face of early whorls barely converge, later whorls converge significantly towards the apex; early whorls with 3 spiral cords of approximately equal strength; on late whorls, abapical spiral cord (low on whorls) strengthened, prominently protruding, angulating whorl face.

Description.

Shell high-spired, very slender; shell 75 mm high; shell flanks straight; sutures distinct; sculpture consists of 3 spiral cords; upper and lower spiral cord at clear distance from adapical and abapical suture respectively; on early whorls, all three spiral cords almost equally strong (middle one slightly weaker than others); whorl face of early whorls barely converge, later whorls converge significantly towards apex; no nodes visible on whorl face; on late whorls abapical spiral cord becomes stronger than others and protrudes noticeably forming an angulation low on whorl; shell ornament reduced on last preserved whorls; base and aperture not preserved; no plaits visible; narrow umbilicus present.

Remarks.

Turritella amitava Das et al., 2018 from India (originally thought to be of Jurassic age but later found to be Miocene: Fürsich et al. 2023, and again as identified as being Upper Jurassic by Das et al. 2024) is smaller, secondary spiral cords are formed next to the 3 main spiral cords, and shows no ontogenetic reduction of the sculpture. Turritella dhosaensis Das et al., 2018 (also of disputed age, Jurassic vs Miocene) is smaller, the abapical and middle spiral cord is are closer to each other than the middle and adapical spiral cord; the abapical spiral cord does not protrude as much on late whorls, and the ontogenetic sculptural change is generally missing. Promathilda (Teretrina) sp. sensu Hägele (1997) is much smaller, has more numerous and weaker but equally strong spiral cords, there is no ontogenetic sculptural reduction. Aptyxiella tricincta (Münster) sensu Quenstedt (1881–1884 ) has a concave or almost straight and vertical whorl face, the subsutural spiral cord is the strongest and the abapical one is not reinforced and does not protrude.

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.