Heliacanthus sp. 1

Plate 3: figs 14–15, Plate 4: Fig. 1

Material.

4 specimens, SNSB – BSPG 2016 XXI 1726 –1729.

Description.

Shell broadly turbiniform with gradate spire; largest specimen 20 mm wide; first recognizable sculpture is a distinct edge situated high on whorl face which separates an approximately horizontal ramp from a vertical abapical part; subsutural spiral cord; two spiral cords appear on either side of edge; orthocline, bulging, blurred axial ribs run from suture to suture; nodules at intersections of axial ribs with subsutural spiral cord and edge; nodes have a pit in apertural direction; base phaneromphalous, slightly convex with angular transition to whorl face; base is covered with 5–6 relatively weak spiral cords in the outer area and three strong nodular spiral ribs near center; all weaker spiral cords are finely crenulated; axial ribs very weak on base; aperture not preserved.

Remarks.

? Nododelphinula sp. sensu Hägele (1997) is smaller, lacks clear axial ribs, the bordering spiral cord at the transition to the base lacks nodes, on the base there is only a hump-shaped spiral cord that surrounds the umbilicus. Heliacanthus epulus (d’Orbigny) sensu Hägele (1997) has smaller and more numerous nodes on the edge, while it lacks a reinforced spiral cord with larger nodes at the transition to the base. Metriomphalus (Metriacanthus) rugosus (Buv.) sensu Fischer and Weber (1997) lacks axial ribs, the nodes on the edge at the transition to the base are larger and less numerous, and its base lacks strong and nodular spiral cords.