Cancilla exornata (Bellardi, 1887)

Harzhauser, Mathias & Landau, Bernard, 2021, The Mitridae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea, Zootaxa 4983 (3), pp. 1-72 : 53

Cancilla exornata (Bellardi, 1887)

Figs 14A 1 –A 2 , B 1 –B 2 , C 1 –C 2 , D

Mitra scrobiculata Brocc. — Hörnes 1852b: 100, pl. 10, fig. 16 [non Brocchi, 1814].

* Mitra exornata Bell. — Bellardi, 1887b: 4, pl. 2, fig. 8, pl. 5, fig. 10.

Mitra (Tiara) colligens Bellardi 1887 —Kojumdgieva in Kojumdgieva & Strachimirov 1960: 158, pl. 42, fig. 4 [non Bellardi, 1887].

Mitra (Nebularia) scrobiculata Brocchi, 1814 — Strausz 1966: 365, pl. 26, fig. 8 [non Brocchi, 1814].

Mitra exornata Bellardi 1887 —Ferrero-Mortara et al. 1981: 162, pl. 50, figs 4a–b.

Cancilla exornata (Bellardi, 1887) — Davoli 2000: 186, pl. 4, figs 1–2, 9–10.

Type material. Syntype ( BS.019.01.183) illustrated in Ferrero Mortara et al. (1981, pl. 50, figs 4a–b), late Miocene ( Tortonian ), San Agata ( Italy), stored in the Museo Regionale di Scienze Naturali, Torino .

Additional material. NHMW 2020 /0111/0001, SL: 36.5 mm , MD: 9.5 mm, Baden ( Austria) , figs 14B 1 –B 2; NHMW 2020 /0111/0002, SL: 50.5 mm , MD: 10.9 mm, Baden ( Austria) , fig. 14D; NHMW 2020 /0111/0003, SL: 45.8 mm , MD: 10.4 mm, Baden ( Austria) , illustrated in Hörnes (1852b, pl. 10, fig. 16), figs 14A 1 –A 2; NHMW 2020 /0111/0004, SL: 36.9 mm , MD: 10.0 mm, Baden ( Austria) , figs 14C 1 –C 2; NHMW 2020 /0111/0005, 12 specimens, Baden ( Austria) .

Revised description (based on Paratethyan material). Shell moderately large, slender fusiform with distinctly incised suture. Protoconch unknown. Teleoconch of eight whorls. Early teleoconch whorls weakly convex with periphery at abapical suture; later whorls nearly straight sided. Spiral sculpture on early teleoconch whorls of six to seven densely spaced, convex cords separated by narrow spiral grooves. Number of spiral cords on subsequent spire whorls about seven or eight; abapically spiral cords narrowing with convex tops, rarely crest-like; spiral grooves widening, often slightly wider than cords. Spiral grooves filled with densely spaced axial riblets. Secondary spiral threads may be intercalated in wide spiral grooves, resulting in delicate, cancellate pattern. Last whorl elongate, slowly contracting with slight basal concavity, with about 18 to 20 spiral cords. Aperture narrow, posteriorly angulated. Columellar callus thin, glossy, sharply delimited, forming small denticle-like swellings where thin callus covers spiral cords on base. Columella with four oblique columellar folds, placed relatively deeply inside aperture, weakening rapidly abapically. Outer lip thin. Siphonal canal long, narrow, straight with deep siphonal notch. No colour pattern in UV light.

Shell measurements and ratios. SL = 36.5–45.8 mm, MD: 9.5–10.9 mm, AA = 24–28°, SL/ MD: 3.8–4.6, AL/AW: 6.0–7.5, AH/S: 1.8–2.1.

Discussion. Cancilla exornata is reminiscent of Cancilla praescrobiculata , but differs in its smaller size and the narrow, convex (not flattish) spiral cords and wide spiral grooves with prominent axial riblets forming a secondary cancellate sculpture. Cancilla elegantissima (Bellardi, 1887) differs from C. exornata in its less elongate shell and higher number of spiral cords, forming a rather regular cancellate pattern with the axial riblets. The holotype of C. elegantissima (illustrated by Ferrero-Mortara et al., 1981, pl. 50, figs 3a–b) derives from the upper Miocene of Stazzano ( Italy) where it co-occurs with C. exornata . It is possible that the two taxa are extreme morphotypes of a single species (see also Davoli 2000: 187). Note that Mitra elegantissima was already used by Röding (1798: 137) for an extant species as nomen nudum. Therefore, Mitra elegantissima Bellardi, 1887 is an available name.

Palaeoenvironment. The specimens from the Vienna Basin were collected from basinal clays of the Baden Formation, indicating middle to outer neritic environments with up to 250 m water depth ( Hohenegger et al. 2008).

Distribution in Central Paratethys. Badenian (middle Miocene): Vienna Basin: Baden, ( Austria) (Hörnes 1852); Pannonian Basin: Szob ( Hungary) ( Strausz 1966); Dacian Basin: Lipen (Kojumdgieva in Kojumdgieva & Strachimirov 1960).

Proto-Mediterranean Sea. Tortonian (late Miocene): Po Basin: Montegibbio, Stazzano, San Agata ( Italy) ( Davoli 2000).

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 14. A1–A2. Cancilla exornata (Bellardi, 1887), Baden (Austria), NHMW 2020/0111/0003. B1–B2. Cancilla exornata (Bellardi, 1887), Baden (Austria), NHMW 2020/0111/0001. C1–C2. Cancilla exornata (Bellardi, 1887), Baden (Austria), NHMW 2020/0111/0004. D. Cancilla exornata (Bellardi, 1887), Baden (Austria), NHMW 2020/0111/0002. E1–E2. Cancilla planicostata (Bellardi, 1887), Coşteiu de Sus(Romania), NHMW 2020/0112/0002.F1–F2. Cancilla planicostata (Bellardi, 1887), Lăpugiu de Sus (Romania), NHMW 1854/0035/0092. G1–G2. Cancilla planicostata (Bellardi, 1887), Coşteiu de Sus (Roma- nia), NHMW 2020/0112/0001. H. Cancilla planicostata (Bellardi, 1887), Coşteiu de Sus (Romania), NHMW 2020/0112/0003. I1–I2. Cancilla praescrobiculata (Toldo, 1889), lectotype of Mitra orientalis Oppenheim, 1918 [non Griffith & Pidgeon, 1834], Baden (Austria), NHMW 1846/0037/0098. J1–J2. Cancilla praescrobiculata (Toldo, 1889), Baden-Sooss (Austria), NHMW 2020/0114/0001. K1–K. Cancilla praescrobiculata (Toldo, 1889), Baden-Sooss (Austria), NHMW 2020/0114/0002. L. Cancilla praescrobiculata (Toldo, 1889), Baden-Sooss (Austria), NHMW 2020/0114/0003.