Metula aliceae, Harzhauser & Landau, 2024

Harzhauser, Mathias & Landau, Bernard M., 2024, The Colubrariidae, Eosiphonidae, Melongenidae, Pisaniidae, Prodotiidae and Tudiclidae (Gastropoda, Buccinoidea) of the Miocene Paratethys Sea, Zootaxa 5427 (1), pp. 1-110 : 12-15

Metula aliceae nov. sp.

Figs 3C 1 –C 2 , 6A–E

Fusus mitraeformis Brocc. —Hörnes 1853: 283, pl. 31, figs 7a–b [non Metula mitraeformis ( Brocchi, 1814) ].

Fusus mitraeformis Brocchi — Neugeboren 1854: 186 [non Metula mitraeformis ( Brocchi, 1814) ].

Fusus (Metula) mitraeformis Brocc. —Hoernes & Auinger 1890: 256 [non Metula mitraeformis ( Brocchi, 1814) ].

? Triton (Epidromus) elongatum Michti. —Hoernes & Auinger 1884: 180, pl. 22, figs 1a–d [non Colubraria elongata ( Michelotti, 1847) ].

Metula mitriformis [sic] (Brocc.)— Boettger 1902: 36 [non Metula mitraeformis ( Brocchi, 1814) ].

Acamptochetus mitriformis [sic] (Brocc.)— Boettger 1906: 47 [non Metula mitraeformis ( Brocchi, 1814) ].

? Acamptochetus mitraeformis (Brocchi) — Montanaro 1935: 75, pl. 6, fig. 19.

A [camptochetus]. Submitraeformis (Orb.) — Sieber 1958: 151 [non Metula major ( Grateloup, 1845) ].

? Metula submitraeformis (d’Orbigny) — Landau et al. 2013: 167, pl. 53, fig. 17, pl. 79, fig. 11.

Metula submitraeformis (d’Orbigny) — Vicián et al. 2017: 271, pl. 3, figs 4–5 [non Metula major ( Grateloup, 1845) ].

Metula major ( Grateloup, 1845) — Kovács 2022: 69, figs 14–17 [non Metula major ( Grateloup, 1845) ].

Metula major ( Grateloup, 1845) — Kovács & Vicián 2023: figs 3C–D [non Metula major ( Grateloup, 1845) ].

Type material. Holotype: NHMW 1874 /0025/0040, SL: 35.4 mm, MD: 11.9 mm, Lăpugiu de Sus ( Romania), Figs 6A 1 –A 3 . Paratypes: NHMW 1870 /0033/0094, SL: 32.3 mm , MD: 12.1 mm, Lăpugiu de Sus ( Romania), Figs 6B 1 –B 2 . NHMW 1865 /0001/0206, SL: 36.4 mm , MD: 11.7 mm, Lăpugiu de Sus ( Romania), Figs 6C 1 –C 3 . NHMW 1854 /0035/0209, SL: 33.9 mm , MD: 13.0 mm, Lăpugiu de Sus ( Romania), Fig. 6D . NHMW 1846 /0037/0277, SL: 28.0 mm , MD: 9.1 mm, Baden ( Austria), illustrated in Hörnes (1853: pl.31,fig.7), Fig.6 E . NHMW 1846 /0037/0277a, SL: 14.4 mm , MD: 5.7 mm, Baden ( Austria), Fig. 3C 1 –C 2 .

Additional paratypes. 6 spec., NHMW 1863 /0015/0186, Lăpugiu de Sus ( Romania) ;

4 spec., NHMW 1866 /0040/0170, Möllersdorf ( Austria) ; 2 spec., NHMW 1869 /0001/0085, Baden-Sooss ( Austria) ; 6 spec., NHMW 1872 /0030/0102, Baden ( Austria) ; 20 spec., NHMW 2013 /0078/0345, Baden ( Austria) .

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 honor of Alice Schumacher (NHMW), who made all the hundreds of pictures of the gastropods described in our series on Paratethyan gastropods.

Diagnosis. Medium-sized, moderately slender fusiform shell with protoconch of three whorls, weakly shouldered early teleoconch whorls bearing tubercles and axial ribs, later teleoconch whorls with numerous very narrow, crowded spiral cords, outer lip finely denticulate.

Description. Medium-sized, moderately slender fusiform shell; apical angle 38–43°. Conical protoconch of 3.2 convex whorls, last protoconch whorl with delicate spiral cord just above abapical suture; diameter: 1000μm, height: 1200μm. Teleoconch of up to six whorls. Early teleoconch whorls high, faintly shouldered. First teleoconch whorl with row of pointed tubercles at shoulder and narrow, widely spaced axial ribs. Second and third teleoconch whorls with additional row of tubercles at adapical suture and two weaker spiral rows below shoulder; tubercles arranged along weakly opisthocline axial ribs. Delicate spiral threads below mid whorl. Tubercles weaken then disappear on third and fourth whorls. Primary spiral cords weaken; synchronously numerous spiral threads appear on fourth to fifth teleoconch whorls. Penultimate and last whorl covered by numerous narrow spiral cords separated by narrow grooves. Shoulder fading out on fourth teleoconch whorl; subsequent whorls evenly convex. Suture on last whorl strongly oblique on dorsal side and rising in apical direction behind aperture. Last whorl high, attaining 62–65% of total height, base slowly constricting, with shallow neck, fasciole indistinct; only terminal varix developed. Aperture narrow, elongate ovate. Columella weakly excavated. Columellar callus forming thin, broad rim, delimited from base by onset of spiral cords. Outer lip slightly thickened bearing row of small elongated denticles placed close behind peristome. Siphonal canal moderately short, moderately wide, slightly deflected to the left, shallowly notched.

Discussion. This species was identified so far as Metula major ( Grateloup, 1845) [= Metula submitraeformis (d’Orbigny, 1852) ] from the Burdigalian of the Aquitaine Basin. Both species are indeed very similar, but the descriptions by Lozouet (2021: pl. 7, figs 1–4) allow a clear separation. Metula major has a paucispiral protoconch and the first teleoconch whorls develop cancellate sculpture. In contrast, Metula aliceae nov. sp. has a planktotrophic protoconch and the early teleoconch whorls have small tubercles. The two species cannot be separated based on teleoconch characters. Metula mitraeformis ( Brocchi, 1814) , from the Pliocene of the Mediterranean Sea, is also very similar in size and shape but differs in the mammillate protoconch, the presence of a spiral row of pointed tubercles below the adapical suture on the first teleoconch whorl and the weaker axial sculpture on early teleoconch whorls (see Chirli 2000: pl. 22, figs 1–6; Garilli & Galletti 2007: figs 4/1–3; Brunetti & Della Bella 2016: figs 15A–G).

Hoernes & Auinger (1890) illustrated a large specimen from Lăpugiu de Sus ( Romania) (SL: 58 mm, MD: 20 mm) as Triton (Epidromus) elongatum ( Michelotti, 1847) . That species was originally described from the Burdigalian of Baldissero ( Italy) ( Michelotti 1847: 280 as Fusus elongatus mihi). The syntype (or holotype) of the Italian species was illustrated by Bellardi (1873: 230, pl. 14, figs 16a–c) as ‘ Triton elongatum (Michtti.) ’, attaining 70 mm in height. As already discussed by Hoernes & Auinger (1890), Metula elongata differs from the Paratethyan species in the more convex whorls, deeper suture, lower aperture and the cancellate sculpture persists to the fifth teleoconch whorl but fades earlier in the specimen illustrated by Hoernes & Auinger (1890). Unfortunately, the specimen from Lăpugiu de Sus is lost, and it remains unclear if it is an exceptionally large Metula aliceae or another, yet undescribed species.

Because information on protoconch morphology is important for the identification, literature data is difficult to evaluate. The specimen from the Serravallian of Turkey, described by Landau et al. (2013) as Acamptochetus submitraeformis might be conspecific with Metula aliceae , but lacks the protoconch. A specimen from the Early/ Middle Miocene of the North Sea Basin, described as Acamptochetus submitraeformis (d’Orbigny, 1852) by A.W. Janssen (1984: pl. 62, fig. 3) is neither Metula aliceae nor Metula major and differs from both species in its very prominent sculpture on the spire whorls. Occurrences from the Early Miocene of Bavaria, described by Hölzl (1958) as Acamptochetus submitraeformis and by Steininger (1973) as Acamptochetus cf. submitraeformis , might represent Metula major , but the preservation does not allow a clear identification. Similarly, occurrences from the Ottnangian (Early Miocene) of Upper Austria, listed by Rupp & Van Husen (2007) and Rupp (2008) as Acamptochetus submitraeformis are most probably based on misidentifications, or will at least need verification.

Paleoenvironment. Occurrences in the Baden Formation of the Vienna Basin suggest middle to outer neritic environments in up to 250 m water depth ( Kranner et al. 2021).

Distribution in Central Paratethys. Badenian (Middle Miocene): Vienna Basin: Baden, Baden-Sooss, Möllersdorf ( Austria) (hoc opus); Pannonian Basin: Letkés ( Hungary) ( Vicián et al. 2017; Kovács & Vicián 2023); Făget Basin: CoŞteiu de Sus, Lăpugiu de Sus ( Romania) (Hoernes & Auinger 1890; Kovács 2022).

? Proto-Mediterranean Sea. Serravallian (Middle Miocene): Karaman Basin: Akpınar Turkey ( Landau et al. 2013). Tortonian (Late Miocene): Po Basin: Montegibbio ( Italy) ( Montanaro 1935).

Figures

FIGURE 1. Measurements for shell morphology; AA: apical angle, SL: shell length, MD: maximum diameter, LWH: last whorl height, AH: aperture height, AL: aperture length, AW: aperture width.

FIGURE 2. Colubraria subobscura (Hoernes & Auinger, 1884). A1–A3. NHMW 1854/0035/0170, paralectotype, Lăpugiu de Sus (Romania). B1–B2. NHMW 1859/0037/0018a, paralectotype, Lăpugiu de Sus (Romania). C1–C3. NHMW 1865/0001/0183, paralectotype, Lăpugiu de Sus (Romania). D1–D2. NHMW 1859/0037/0018b, paralectotype, Lăpugiu de Sus (Romania). E1–E3. NHMW 1874/0025/0021, lectotype, Lăpugiu de Sus (Romania). F1–F2. NHMW 2023/0338/0001, paralectotype, Lăpugiu de Sus (Romania).

FIGURE 3. A. Colubraria subobscura (Hoernes & Auinger, 1884), NHMW 2023/0338/0002, Lăpugiu de Sus (Romania). B. Metula kovacsi nov. sp., NHMW 1867/0019/0078, holotype, CoŞteiu de Sus (Romania). C1–C2. Metula aliceae nov. sp. NHMW 1846/0037/0277a, paratype, Baden (Austria).

FIGURE 6. Metula aliceae nov. sp. A1–A3. NHMW 1874/0025/0040, holotype, Lăpugiu de Sus (Romania). B1–B2. NHMW 1870/0033/0094, paratype, Lăpugiu de Sus (Romania). C1–C3. NHMW 1865/0001/0206, paratype, Lăpugiu de Sus (Romania). D. NHMW 1854/0035/0209, paratype, Lăpugiu de Sus (Romania). E. NHMW 1846/0037/0277, paratype, Baden (Austria).