Episcomitra neubaueri, Harzhauser & Landau, 2021

Harzhauser, Mathias & Landau, Bernard, 2021, The Mitridae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea, Zootaxa 4983 (3), pp. 1-72 : 22-24

Episcomitra neubaueri nov. sp.

Figs 5G 1 –G 2 , H 1 –H 2 , I 1 –I 2

Mitra fusiformis Brocc. — Hoernes & Auinger 1880: 75, pl. 8, figs 27, 29 [non Brocchi, 1814].

Type material. Holotype: NHMW 1854 /0035/0084, SL: 33.4 mm, MD: 12.2 mm, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1880, pl. 8, figs 27a–b), figs 5G 1 –G 2 . Paratypes: NHMW 1854 /0035/0086, SL: 37.6 mm , MD: 12.8 mm, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1880, pl. 8, figs 29a–b); figs 5H 1 –H 2 ; NHMW 1855 /0043/0006, SL: 36.4 mm , MD: 12.3 mm, Lăpugiu de Sus ( Romania), figs 5I 1 –I 2 .

Additional material. NHMW 1857/0024/0011, Lăpugiu de Sus ( Romania; NHMW 1854/0035/0085, 22 specimens, Lăpugiu de Sus ( Romania).

Type locality. Lăpugiu de Sus ( Romania), Făget Basin .

Type stratum. Silt and clay of the Dej Formation.

Age. Middle Miocene, early/middle Badenian (Langhian).

Etymology. In honour of Thomas A. Neubauer (University Giessen, Germany) in respect for his contributions on Neogene malacology.

Diagnosis. Episcomitra species of medium size, moderately broad drop-shaped profile, with high conical spire, narrowly incised suture, prominent spiral cords in adapical third of whorls, and moderately constricted base.

Description. Shell medium sized, moderately broad drop-shaped with conical spire. Protoconch unknown. Teleoconch consisting of nine whorls. Spire whorls straight sided, suture narrowly incised. Early three to four spire whorls bearing seven broad, flat spiral cords separated by narrow grooves. Spiral cords increasing in number on later spire whorls by intercalations of secondary spiral grooves, but becoming blurred and indistinct below subsutural area in most specimens. Spiral cords most prominent in adapical third of whorls. No axial sculpture except for prosocline growth lines in some specimens. Last whorl ovoid with convex periphery placed mid-whorl, straight sided above, moderately constricted below, with distinct basal concavity. Broad, flattish spiral cords on base and fasciole. Aperture elongate, moderately wide to wide, posteriorly narrowly angulated, posterior sinus indistinct. Columellar callus sharply delimited between adapical columellar fold and terminal tip of siphonal canal. Columella with four oblique columellar folds. Outer lip thin. Siphonal canal moderately short, moderately wide, straight with incised siphonal notch.

Shell measurements and ratios. SL = 33.4–37.6 mm, MD: 12.2–12.8 mm; AA = 32–37°, SL/MD: 2.7–3.0, AL/AW: 3.5–4.1, AH/S: 2.6–2.8.

Discussion. Hoernes & Auinger (1880) confused this species with the Pliocene Episcomitra fusiformis ( Brocchi, 1814) , which differs considerably in its larger size, higher spire, convex spire whorls and high, weakly constricted last whorl. Episcomitra neubaueri is characterised by its drop-shaped outline, conical spire and spiral sculpture. Indeed, if it were not for the columellar folds, one might consider it a columbellid. We are not aware of similar species in the European Neogene.

Distribution in Central Paratethys. Badenian (middle Miocene): Făget Basin: Lăpugiu de Sus ( Romania) ( Hoernes & Auinger 1880).

Genus Calcimitra Huang, 2011

Type species. Calcimitra kingtsio Huang, 2011 ; by original designation. Present-day, Indo-West Pacific.

Diagnosis. “ Shell medium sized to large (35–125 mm), elongate-fusiform, with high orthoconoid or slightly acuminate spire and slender, tapering siphonal canal. Protoconch narrowly conical, multispiral, of about three smooth convex whorls. Suture deeply impressed or canaliculate. Spire whorls flattened to evenly convex, smooth or sculptured with weak and irregular, or distinct, evenly set cords. Interspaces between spiral cords sometimes ornamented with fine collabral growth lines or dense riblets sometimes forming fine cancellate sculpture pattern. Siphonal canal long, tapering, with shallow or indistinct siphonal notch. Aperture elongate, its outer lip smooth, evenly convex. Inner aperture lip often callused, sometimes reflected, bearing three to four fine columellar folds ” ( Fedosov et al., 2018: 31).

Discussion. Calcimitra is a rather recently described genus of extant deep water Mitridae ( Huang 2011) , which was confirmed by molecular data ( Fedosov et al. 2018). No fossil species have been ascribed to the genus so far. The placement of the Miocene Paratethyan species in Calcimitra is based on the slender elongate fusiform shell profile, faintly cancellate early teleoconch sculpture, weakly canaliculate suture, long, twisted siphonal canal, and callused inner lip. A difference, however, is the smaller size, which makes Calcimitra bellardii ( Hoernes & Auinger, 1880) the smallest known species of the genus. The extant Indo-West Pacific Calcimitra invicta ( Huang & Salisbury, 2017) and Calcimitra philosopha ( Huang & Salisbury, 2017) are highly reminiscent of Calcimitra bellardii . Both species differ from this Miocene species mainly in their larger size and their uniform spiral sculpture.

Some Calcimitra species are superficially similar to some member of the genus Cancilla Swainson, 1840 , now placed in the Imbricariinae Troschel, 1867 , but differ in their cancellate early teleoconch whorls, their spiral cords that are slightly gemmate or with finely dentate margins or stronger elevated cords, and more strongly developed columellar callus. If our interpretation of the genus based on shell characters is correct, several other Neogene species should also be transferred to Calcimitra , such as the species included in Bellardi’s (1887b: 12) “ 46 a Serie ” (i.e. Mitra pulcherrima Bellardi, 1887 , M. bronni Michelotti, 1847 , M. separata Bellardi, 1887 , M. ligustica Bellardi, 1887 , M. fusulus Cocconi, 1873 and M. contigua Bellardi, 1887 ).

Present-day distribution. Indo-West Pacific ( Fedosov et al. 2018).

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 5. A1–A2. Episcomitra brusinai (Hoernes & Auinger, 1880), lectotype, Lăpugiu de Sus (Romania), NHMW 1854/0035/0100. B1–B2. Episcomitra cf. brusinai (Hoernes & Auinger, 1880), Steinebrunn (Austria), NHNW 2020/0123/0001. C1–C2. Episcomitra missile nov. sp., holotype, Guntersdorf (Austria), NHMW 202/0127/0001. D1–D2. Episcomitra missile nov. sp., paratype, Grund (Austria), NHMW 202/0128/0001. E1–E2. Episcomitra friedbergi (Cossmann, 1912), lectotype, Lăpugiu de Sus (Romania), NHMW 20200124/0001. F1–F2. Episcomitra friedbergi (Cossmann, 1912), Lăpugiu de Sus (Romania), NHMW 1868/0001/0398. G1–G2. Episcomitra neubaueri nov. sp., holotype, Lăpugiu de Sus (Romania), NHMW 1854/0035/0084. H1– H2. Episcomitra neubaueri nov. sp., paratype, Lăpugiu de Sus (Romania), NHMW 1854/0035/0086. I1–I2. Episcomitra neubaueri nov. sp., paratype, Lăpugiu de Sus (Romania), NHMW 1855/0043/0006.