Loriolotrema sp.

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

Loriolotrema sp.

Plate 8: figs 2–4

Material.

1 specimen, SNSB-BSPG 2016 XXI 1780 .

Description.

Shell broadly biconical, with gradate spire, 17 mm high, whorls low, rapidly increasing in width; edge at about mid-whorl of first preserved whorls, delimiting oblique ramp from approximately vertical abapical portion; weak spiral cords present on both sides of edge; orthocline axial ribs run from suture to suture, with wide interspaces; nodes at intersections of ribs and edge; edge strengthened during ontogeny and axial ribs become broadly bulging and blurred; nodes on intersections of ribs and edge become larger, rounder and also include the spiral cord located between edge and bordering spiral cord as well as bordering spiral cord; several spiral cords can be seen on wide, oblique ramp; base slightly convex with 4 (5?) spiral cords broken down into individual segments; spiral cords on base crossed by weakly strengthened growth lines; base phaneromphalous; aperture strongly damaged.

Remarks.

Loriolotrema? nodosa Gründel, Hostettler and Menkveld-Gfeller is larger, the strong enlargement of the nodes begins later in ontogeny, the spiral cords on the base are not divided into partial segments. Brachytrema kobyi Loriol in Loriol and Koby (1889) is more slender, the whorls have a stronger keel and the base has more and unsegmented spiral cords. Brachytrema filosum (Buvignier) sensu Cossmann (1913) is more slender, has more spiral cords on the base, the axial ribs are not as wide and the nodes on the edge are not as large.

Figures

Plate 8. (1) Saalensia birugata Gründel, Keupp & Lang, 2019, SNSB-BSPG 2016 XXI 1779, lateral view, height 16 mm. (2–4) Loriolotrema sp., SNSB-BSPG 2016 XXI 1780, apertural, apical and basal view, width 18 mm. (5) Brachytrematidae? gen. and sp. indet., SNSB-BSPG 2016 XXI 1781, abapertural view, height 29 mm. (6, 7) Oonia kimmeridgiensis sp. nov., holotype, SNSB-BSPG 2016 XXI 1791, apertural and abapertural, height 18 mm. (8, 9) Globularia? sp., SNSB-BSPG 2016 XXI 1794, abapertural and oblique lateral view, width 42 mm. (10, 11) Pictavia? sp., SNSB-BSPG 2016 XXI 1790, abapertural and oblique abapertural view, height 20 mm. (12) Eustoma sp., SNSB-BSPG 2016 XXI 1801, apertural view, height 24 mm. (13, 14) Eustoma sp., SNSB-BSPG 2016 XXI 1802, (13) lateral view, height 31 mm, (14) basal view, width 10 mm. (15–17) Eustoma? gracilis sp. nov., holotype, SNSB-BSPG 2016 XXI 1804, (15–16) basal and lateral view, width 18 mm, (17) detail of ornament of last whorl, height 15 mm.