Mitrella viennensis, Harzhauser & Landau, 2021

Harzhauser, Mathias & Landau, Bernard M., 2021, The Columbellidae (Gastropoda, Buccinoidea) in the Miocene Paratethys Sea — striking diversity of a negelected group, Zootaxa 5025 (1), pp. 1-75 : 33-35

Mitrella viennensis nov. sp.

Figs 4H, 11D 1 –D 2 , E 1 –E 2 , F 1 –F 2 , G 1 –G 2 , H 1 –H 2 , I 1 –I 2

Buccinum turgidulum — Hauer 1837: 417 [non Bronn, 1831].

Columbella scripta Bell. —Hörnes 1852: 116, pl. 11, figs 12, 14.

Columbella (Mitrella) scripta Linné. — Hoernes & Auinger 1880: 95 [non Linnaeus, 1758].

Columbella (Mitrella) scripta L.— Boettger 1906: 15 [non Linnaeus, 1758].

Mitrella scripta L.— Meznerics 1933: 340 [non Linnaeus, 1758].

Mitrella scripta L.— Sieber 1953: 187 [non Linnaeus, 1758].

Mitrella (M [itrella].) scripta (L.)— Sieber 1958b: 148 [non Linnaeus, 1758].

Mitrella (Atilia) falax [sic] (Hörnes & Auinger 1880)—Kojumdgieva in Kojumdgieva & Strachimirov 1960: 183, pl. 45, fig. 6 [non Hoernes & Auinger, 1880].

Mitrella (Mitrella) scripta (Linnaeus) — Švagrovský 1960: 101, pl. 9, figs 9–10 [non Linnaeus, 1758].

Mitrella (Mitrella) scripta (Linné, 1758) — Iljina 1993: 98, pl. 13, figs 4–6 [non Linnaeus, 1758].

Pyrene (Mitrella) semicaudata (Bellardi, 1849) — Bałuk 1995: 235, pl. 31, figs 1–3 [non Bellardi, 1848].

non Columbella (Mitrella) scripta L.— Friedberg 1911: 37, pl. 2, fig. 4 [non Linnaeus, 1758].

non Mitrella scripta (Linné, 1766) — Zelinskaya 1968: 207, pl. 48, figs 15–16 [non Linnaeus, 1758].

Type material. Holotype: NHMW1855 /0045/0391, SL: 14.1 mm, MD: 5.3 mm, Mikulov (the Czech Republic), illustrated in Hörnes (1852, pl. 11, figs 14a–b), Figs 11D 1 –D 2 . Paratypes: NHMW 2020 /0165/0001, SL: 17.4 mm, MD: 6.3 mm, Steinebrunn ( Austria) , Figs 4H, 11F 1 –F 2 . NHMW1871 /0010/0333a, SL: 17.1 mm, MD: 6.3 mm, Steinebrunn ( Austria) , illustrated in Hörnes (1852, pl. 11, figs 12a–b), Figs 11E 1 –E 2 . NHMW 2006 /0321/0012, SL: 20.5 mm, MD: 7.8 mm, Gainfarn ( Austria) , 11G 1 –G 2. NHMW 2006 /0321/0012a, SL: 23.1 mm, MD: 8.5 mm, Gainfarn ( Austria) , Figs 11H 1 –H 2 . NHMW 2006 /0321/0012b, SL: 20.9 mm, MD: 7.9 mm, Gainfarn ( Austria) , Figs 11G 1 –G 2 .

Additional material. NHMW1846 /0037/0157, 65 spec., mixed lot, Steinebrunn ( Austria) , Gainfarn ( Austria) , Mikulov (the Czech Republic) ; NHMW2020 /0177/0001 (ex B. Landau coll.), 8 spec., Gainfarn ( Austria) .

Type locality. Steinebrunn ( Austria), Vienna Basin .

Type stratum. Sandy silt of the Baden Formation.

Age. Middle Miocene, Badenian.

Etymology. Referring to Vienna ( Austria).

Diagnosis. Medium sized, moderately broad biconic shell characterized by high conical spire of low, weakly convex whorls grading into comparatively wider, higher and more convex penultimate whorl followed by moderately convex high last whorl.

Description. Medium sized, moderately broad biconic shell with high, slightly coeloconoid spire and narrowlyincised suture. Dome-shaped protoconch poorly preserved in available specimens, moderately convex, probably paucispiral. Teleoconch of nine whorls. Early spire whorls low, only weakly convex, regularly increasing in width. Seventh whorl slightly more convex; penultimate whorl increasing in growth rate with distinct convexity, periphery in abapical third of whorl. Convexity decreasing again on high last whorl. Base weakly constricted. Aperture moderately wide to moderately narrow. Columellar callus forming broad, thickened rim with six small denticles. Parietal callus weak, thin, adherent. Outer lip moderately thickened with seven prominent denticles inside. Anal canal narrowly incised, V-shaped. Siphonal canal short, narrow, slightly deflected with deep siphonal notch.

Shell measurements and ratios. SL: 14.1–23.1 mm, MD: 5.3–8.5 mm, AA: 35–37°, SL/MD: 2.7–2.9, AL/AW: 3.4–3.9, LWH/AH: 1.2–1.3.

Discussion. This species was confused by Hörnes (1852) and subsequent authors with the extant Mitrella scripta ( Linnaeus, 1758) , which differs in its higher and less numerous spire whorls. In the museum lots (NHMW), Mitrella viennensis nov. sp. was mixed with Mitrella complanata (Sacco, 1890) and misidentified as Mitrella semicaudata ( Bellardi, 1848) . Mitrella viennensis is readily distinguished from M. complanata by its convex spire whorls and the slightly allometric growth rate, resulting in a coeloconoid spire. Mitrella semicaudata differs in its much higher spire whorls and the conical to weakly cyrtoconoid spire outline. Mitrella inflatula ( Millet, 1865) , from the Tortonian of France, has a shorter spire, a more inflated last whorl and a broader columellar callus ( Landau et al. 2019 pl. 21, figs 1–4).

Palaeoenvironment. The occurrence at Steinebrunn suggests inner neritic environments with sea grass (own data).

Distribution in Central Paratethys. Badenian (middle Miocene): Carpathian Foredeep: Korytnica ( Poland) ( Bałuk 1995); Vienna Basin: Steinebrunn, Vienna /Pötzleinsdorf ( Austria) ( Sieber 1953), Mikulov (the Czech Republic) ( Hoernes & Auinger 1880); Făget Basin: Coşteiu de Sus, Lăpugiu de Sus ( Romania) ( Boettger 1906); Dacian Basin: Târnene, Opanec ( Bulgaria) (Kojumdgieva in Kojumdgieva & Strachimirov 1960).

Eastern Paratethys. Konkian (middle Miocene): Mangyshlak ( Kazakhstan) ( Iljina 1993).

Figures

FIGURE 1. A. Map of central and south–eastern Europe, representing the area that was partly covered by the Central Paratethys Sea. The white insert corresponds to the area that is restored in the palaeogeographic map below. B. Paleogeography of the Middle Miocene Paratethys Sea showing the most important sedimentary basins (NAFB: North Alpine Foreland Basin, E–Sopr B: Eisenstadt–Sopron Basin).

FIGURE 2. Measurements for 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.