Vexillum michelottii (Hörnes, 1852)

Harzhauser, Mathias & Landau, Bernard, 2021, An overlooked diversity-the Costellariidae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea, Zootaxa 4982 (1), pp. 1-70 : 52

Vexillum michelottii (Hörnes, 1852)

Figs 4N , 16I 1 –I 2 , J 1 –J 2 , K 1 –K 2 , L 1 –L 2 , M

* Mitra Michelottii Hörnes — Hörnes 1852b: 105, pl. 10, figs 30a–b.

[ Mitra ] Michelottii Hörnes — Auinger 1871: 8.

[ Callithea ] Michelottii M. Hoern.—Hoernes 1880: 125.

cf. Mitra (Callithea) Michelottii M. Hoernes— Hoernes & Auinger 1880: 87, figs 11a–c.

Mitra michelottii Hörnes — Toth 1948: 412.

V [exillum]. (U [romitra].) michelottii (Hörn.) — Sieber 1958a: 153.

Type material. Lectotype (designated herein): NHMW 1851 /0013/0001, SL: 20.3 mm, MD: 5.4 mm, Baden ( Austria), illustrated in Hörnes (1852b, pl. 10, figs 30a–b), figs 4N, 16I 1 –I 2 . Paralectotype: NHMW 2020 /0088/0001, SL: 19.8 mm, MD: 4.7 mm, Baden ( Austria), figs 16 J 1 –J 2 .

Additional material. NHMW 1869 /0001/0249, SL: 26.5 mm, MD: 7.3 mm, Möllersdorf ( Austria) , figs 16L 1 –L 2; NHMW 2020 /0089/0001, SL: 25.1 mm, MD: 7.3 mm, Möllersdorf ( Austria) , figs 16K 1 –K 2; NHMW 1875 /0009/0007, SL: 15.3 mm, MD: 4.3 mm, Lăpugiu de Sus ( Romania) , illustrated in Hoernes & Auinger (1880, pl. 10, figs 11a–c), fig. 16M; NHMW 1874 /0024/0003, 2 specimens, Baden ( Austria) ; NHMW 1869 /0040/0035, Hrušovany nad Jevišovkou ( Czech Republic) , NHMW 1862 /0039/0009, 2 specimens, Rudice ( Czech Republic) , NHMW 1854 /0035/0098, 5 specimens, Lăpugiu de Sus ( Romania) .

Revised description. Shell large, slender fusiform, with high spire. Protoconch multispiral, high conical, of three smooth, weakly convex whorls (height: 730 μm, diameter: 550 μm). Teleoconch of nine convex whorls, with periphery at mid-whorl or slightly below, separated by deeply incised suture. Axial sculpture on early teleoconch whorls of about ten prominent, convex, weakly opisthocline, widely spaced axial ribs, crossed by deep spiral groove close below adapical suture, forming subsutural band. Adapical tips of axials form nodes on subsutural band. Subsutural band may split into two or three narrow-spaced spiral cords by intercalation of secondary spiral grooves. Spiral cords appear between third to fifth teleoconch whorl below subsutural band, forming nodes or beads at intersections with axial ribs and grooves in axial interspaces. Number of spiral cords variable due to intercalations of secondary cords. Last whorl convex, moderately constricted at base. Axial sculpture weakening on base and fasciole, replaced by about 10 to 12 spiral cords, some extending from columellar folds. Aperture elongate, moderately narrow; columellar callus indistinct. Columella with three folds, weakening abapically. Outer lip thin, with about 11 to 15 long, delicate lirae within. Siphonal canal long, weakly deflected, with very shallow siphonal notch.

Shell measurements and ratios. SL: 15.3–26.5 mm, MD: 4.3–7.3 mm; AA: 23–30°, SL/MD: 3.4–4.1, AL/AW: 4.7–5.6, AH/S: 2.1.

Discussion. Vexillum michelottii is a rather polymorphic species concerning the spire angle and especially the sculpture on fully grown specimens. The sculpture ranges from rectangular nodulose to densely beaded depending on a variable number of intercalations of secondary spiral cords. Nevertheless, all available specimens display identical sculpture on early teleoconch whorls and have only three columellar folds. Therefore, we consider all specimens to represent a single species. The specimen from Lăpugiu de Sus, discussed by Hoernes & Auinger (1880) as “variety” of V. michelottii , has numerous healed fractures from repeated attacks by crabs or other predators ( Fig. 16M ). The aberrant outline and sculpture is probably pathological.

Palaeoenvironment. The localities Baden and Möllersdorf belong to the Baden Formation suggesting middle neritic settings with up to 250 m water depth ( Hohenegger et al. 2008).

Distribution in Central Paratethys. Badenian (middle Miocene): North Alpine-Carpathian Foredeep: Hrušovany nad Jevišovkou ( Czech Republic) ( Hoernes & Auinger 1880); Vienna Basin: Baden, Möllersdorf ( Austria), Rudice ( Czech Republic) ( Hoernes & Auinger 1880); Făget Basin: Lăpugiu de Sus ( Romania).

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 4. Protoconchs of Paratethyan Costellariidae. A. Antithala filipescui nov. sp., Lăpugiu de Sus (Romania), NHMW 1876/0011/0012). B. Antithala sturi (Hoernes & Auinger, 1880), Lăpugiu de Sus (Romania), NHMW 2020/0058/0001. C. Bellardithala kovaci nov. sp., Steinebrunn (Austria), NHMW 2020/0062/0001. D. Bellardithala partschi (Hörnes, 1852), Steinebrunn (Austria), NHMW 2020/0060/0003. E. Ebenomitra leucozona (Andrzejowski, 1830), Lăpugiu de Sus (Romania), NHMW 1876/0011/0008. F. Ebenomitra pseudopyramidella (Boettger, 1906), Steinebrunn (Austria), NHMW 1857/0014/0009. G. Fedosovia fuchsi (Hoernes & Auinger, 1880), lectotype, Lăpugiu de Sus (Romania), NHMW 1857/0024/0012. H. Pusia avellanella (Boettger, 1906), Gainfarn (Austria), NHMW 2020/0072/0001. I. Pusia? confunda nov. sp., holotype, Coşteiu de Sus (Romania), SMF 360341. J. Pusia pseudorecticosta (Boettger, 1906), Pusia pseudorecticosta (Boettger, 1906), Steinebrunn (Austria), NHMW 2020/0076/0005. K. Pusia schafferi (Meznerics, 1933), Steinebrunn (Austria), NHMW 2020/0078/0002. L. Pusia vexans (Boettger, 1902), Coşteiu de Sus (Romania), NHMW 2020/0081/0001. M. Vexillum intermittens (Hoernes & Auinger, 1880), paralectotype, Baden or Bad Vöslau (Austria), NHMW 2020/0087/0003. N. Vexillum michelottii (Hörnes, 1852), lectotype, Baden (Austria), NHMW 1851/0013/0001. O. Tosapusia pseudocupressina Bałuk, 1997, Lăpugiu de Sus (Romania), NHMW 1870/0033/0037.

FIGURE 16 A1–A2. Vexillum badense (Hoernes &Auinger, 1880), lectotype, Baden (Austria), NHMW 1846/0037/0102. B1–B2. Vexillum badense (Hoernes & Auinger, 1880), paralectotype, Vienna/Grinzing (Austria), NHMW 2020/0084/0001. C1–C2. Vexillum badense (Hoernes & Auinger, 1880), paralectotype, Baden (Austria), NHMW 2020/0085/0001. D1–D2. Vexillum badense (Hoernes & Auinger, 1880), paralectotype, Baden (Austria), NHMW 2020/0085/0002. E1–E2. Vexillum intermittens (Hoernes & Auinger, 1880), paralectotype, Bad Vöslau (Austria), NHMW 1863/0015/0624. F1–F2. Vexillum intermittens (Hoernes & Auinger, 1880), paralectotype, Bad Vöslau (Austria), NHMW 2020/0087/0001. G1–G2. Vexillum intermittens (Hoernes & Auinger, 1880), lectotype, Bad Vöslau (Austria), NHMW 1846/0037/0105. H1–H2. Vexillum intermittens (Hoernes & Auinger, 1880), paralectotype, Baden or Bad Vöslau (Austria), NHMW 2020/0087/0002. I1–I2. Vexillum michelottii (Hörnes, 1852), lectotype, Baden (Austria), NHMW 1851/0013/0001. J1–J2. Vexillum michelottii (Hörnes, 1852), paralectotype, Baden (Austria), NHMW 2020/0088/0001. K1–K2. Vexillum michelottii (Hörnes, 1852), Möllersdorf (Austria), NHMW 2020/0089/0001. L1–L2. Vexillum michelottii (Hörnes, 1852), Möllersdorf (Austria), NHMW 1869/0001/0249. M. Vexillum michelottii (Hörnes, 1852), Lăpugiu de Sus (Romania), NHMW 1875/0009/0007.