Vexillum harmati ( Csepreghy-Meznerics, 1954 )

Harzhauser, Mathias & Landau, Bernard, 2021, An overlooked diversity-the Costellariidae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea, Zootaxa 4982 (1), pp. 1-70 : 50-51

Vexillum harmati ( Csepreghy-Meznerics, 1954)

Figs 17A 1 –A 2 , B 1 –B 2 , C 1 –C 2 , D 1 –D 2 , E 1 –E 2

* Vexillum (Costellaria) harmati n. sp. — Csepreghy-Meznerics 1954: 45, pl. 5, figs 29, 31–33.

Mitra (Vexillum) harmati Csepreghy-Meznerics, 1954 — Strausz 1966: 368, pl. 12, fig. 9.

Type material. Holotype: M.61.4361, Hungarian Natural History Museum, SL: 24.0 mm, MD: 6.2 mm, Sámsonháza ( Hungary) ( Pálfy et al. 2008), figs 17A 1 –A 2 . Paratypes: M.61.4362, 3 specimens, Hungarian Natural History Museum, SL: 15.0 mm, MD: 3.9 mm, Sámsonháza ( Hungary) ( Pálfy et al. 2008), Figs 17B 1 –B 2 , C 1 –C 2 , D 1 –D 2 , E 1 –E 2 .

Revised description. Shell moderately large, slender fusiform, with very high spire. Protoconch unknown. Teleoconch of nine high, subcylindrical to weakly convex whorls, with periphery mid-whorl, separated by incised suture. Sculpture of widely spaced, sharp-crested, orthocline to weakly opisthocline axial ribs, most prominent along periphery, weakening towards adapical and abapical suture. Axial sculpture fading out on seventh spire whorl; penultimate and last whorls smooth. Last whorl high, subcylindrical, weakly shouldered, moderately constricted at base. No spiral sculpture except for faint spiral cords on weak fasciole. Aperture narrow elongate. Columellar callus indistinct, columella with four oblique folds. Outer lip not preserved. Siphonal canal moderately long, wide, slightly bent to left, with wide, shallow siphonal notch.

Shell measurements and ratios. SL: 15.0–24.0 mm, MD: 3.9–6.2 mm; AA: 24–30°, A/S: 0.6–0.7.

Discussion. This species is reminiscent of Vexillum badense ( Hoernes & Auinger, 1880) and Vexillum intermittens ( Hoernes & Auinger, 1880) , but is distinguished from both species by its distinctly more slender shell and higher spire whorls. Its axial ribs are most prominent mid-whorl, whereas in the other two species they strengthen towards the abapical suture. Finally, the occurrence in silty-sandy nearshore deposits of Sámsonháza indicates an ecological separation from V. badense and V. intermittens , which are confined to basinal settings.

Palaeoenvironment. The Sámsonháza Formation represents inner neritic shallow water environments ( Kovács & Vicián, 2017).

Distribution in Central Paratethys. Badenian (middle Miocene): Pannonian Basin: Sámsonháza ( Hungary) ( Strausz 1966).

Figures

FIGURE 1. A. Map of central and southeastern Europe, representing the area that was partly covered by the Central Paratethys Sea (for detailed maps with the localities mentioned in the text see Kroh (2005) and Nosowska (2020). The white insert corresponds to the area that is restored in the palaeogeographic map below. B. Paleogeography of the Middle Miocene Paratethys Sea (modified from Harzhauser et al. 2007) showing the most important sedimentary basins (NAFB: North Alpine Foreland Basin, E–Sopr B: Eisenstadt–Sopron Basin).

FIGURE 2. Measurements to shell morphology and whorl profiles. SL: shell length, MD: maximum diameter, AA: apical angle, LWH: last whorl height, AH: aperture height. AL: aperture length. AW: aperture width. S: length of siphonal canal.

FIGURE 17 A1–A2. Vexillum harmati (Csepreghy-Meznerics, 1954), holotype, M.61.4361, Sámsonháza (Hungary). B1–B2. Vexillum harmati (Csepreghy-Meznerics, 1954), paratype, M.61.4362, Sámsonháza (Hungary). C1–C2. Vexillum harmati (Csepreghy-Meznerics, 1954), paratype, M.61.4362, Sámsonháza (Hungary). D1–D2. Vexillum harmati (Csepreghy-Meznerics, 1954), paratype, M.61.4362, Sámsonháza (Hungary). E1–E2. Vexillum harmati (Csepreghy-Meznerics, 1954), paratype, M.61.4362, Sámsonháza (Hungary).