Episcomitra facilis ( Mayer-Eymar, 1890 ) Harzhauser & Landau, 2021

Harzhauser, Mathias & Landau, Bernard, 2021, The Mitridae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea, Zootaxa 4983 (3), pp. 1-72 : 12

Episcomitra facilis ( Mayer-Eymar, 1890) nov. comb.

Figs 3F 1 –F 2

* Mitra facilis May.-Eym.— Mayer-Eymar 1890: 299.

Mitra facilis Mayer-Eymar — Mayer-Eymar 1891: 338, pl. 10, fig. 6.

Mitra facilis Mayer-Eymar, 1891 — Cernohorsky 1976: 377.

Type material. Holotype: Inv. Nr. t3308, illustrated in Mayer-Eymar (1891, pl. 10, fig. 6), SL: 15 mm, MD: 6 mm, Lăpugiu de Sus ( Romania), stored in the collection of the Naturhistorisches Museum Basel ( Switzerland), figs 3F 1 –F 2.

Revised description. Shell small, moderately broad, ovoid with broad conical, slightly gradate spire and impressed suture. Protoconch unknown. Teleoconch of seven whorls. Spire whorls straight sided with periphery at abapical suture. Sculpture of eight broad, flattish spiral cords separated by narrow, punctate, shallow interspaces. Last whorl ovoid, nearly straight sided above convex periphery, constricted at base with distinct basal concavity. Spiral cords on penultimate and last whorls slightly blurred, most prominent on base and fasciole. Aperture moderately wide, elongate with weakly incised anal canal. Columellar callus thin, sharply delimited. Outer lip solid. Columella with four prominent columellar folds. Siphonal canal moderately long, wide, straight, with deep siphonal notch.

Shell measurements and ratios. SL = 15 mm, MD: 6 mm, AA = 43°, SL/ MD: 2.6, AL/AW: 4.2, AH/S: 2.3.

Discussion. Episcomitra facilis ( Mayer-Eymar, 1890) is characterised by its stout ovoid profile and the broad, depressed spiral cords. Mitra observabilis Bellardi, 1887 , from the Burdigalian of the Colli Torinesi ( Italy) is morphologically very similar (see holotype in Bellardi 1887a, pl. 3, fig. 16 and Ferrero-Mortara et al. 1981, pl. 45, figs 2a–b). The Italian species attains the same size and develops an almost identical spiral sculpture, but its base is less constricted and the siphonal notch is much shallower. In respect to the stratigraphic gap, we prefer to keep both taxa as separate species. Episcomitra cochlearella ( Mayer-Eymar, 1890) , with which it co-occurs at Lăpugiu de Sus, is not as broad, has a taller spire and finer spiral sculpture.

Palaeoenvironment. Unknown.

Distribution in Central Paratethys. Badenian (middle Miocene): Făget Basin: Lăpugiu de Sus ( Romania) ( Mayer-Eymar 1890).

Figures

FIGURE 1. A. Map of central and south–eastern 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. Palaeogeography of the Middle Miocene Paratethys Sea (modified from Harzhauser & Landau 2017) 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. S: length of siphonal canal.

FIGURE 3. A1–A2. Episcomitra antibellardii nov. sp., holotype, Lăpugiu de Sus (Romania), NHMW 1854/0035/0100b. B1–B2. Episcomitra antibellardii nov. sp., paratype, NHMW 1854/0035/0100c. C1–C2. Episcomitra bouei (Hoernes & Auinger 1880), lectotype, Lăpugiu de Sus (Romania), NHMW 1854/0035/0100d. D1–D2. Episcomitra cochlearella (Mayer-Eymar, 1890), lectotype, Lăpugiu de Sus (Romania), NMB Inv. Nr. t3238). E1–E2. Episcomitra cochlearella (Mayer-Eymar, 1890), paralectotype, Lăpugiu de Sus (Romania), NMB Inv. Nr. t3238. F1–F2. Episcomitra facilis (Mayer-Eymar, 1890), holotype, Lăpugiu de Sus (Romania), Inv. Nr. t3308. G1–G2. Episcomitra hilberi (Hoernes & Auinger 1880), paralectotype, Lăpugiu de Sus (Romania), NHMW 1854/0035/0100. H1–H2. Episcomitra hilberi (Hoernes & Auinger 1880), lectotype, Jerutek at Lysice (Czech Republic), NHMW 1865/0015/0014. I1–I2. Episcomitra pilsbryi (Boettger, 1906), holotype, Coşteiu de Sus (Romania), SFM 360347 (= SFM XII 12.2207a).