Costoanachis guembeli ( Hoernes & Auinger, 1880 ) 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 : 14-17

Costoanachis guembeli ( Hoernes & Auinger, 1880) nov. comb.

Figs 4L, 5A 1 –A 2 , B 1 –B 2 , C 1 –C 2 , D 1 –D 2 , E 1 – E 2 , 6A 1 –A 2

Buccinum minutissimum Partsch — Hörnes 1848: 17 [nomen nudum].

Columbella corrugata Bon. —Hörnes 1852: 120, pl. 11, figs 7a–c [non Bellardi, 1848].

[ Anachis ] Gümbelii nov. form.—Hoernes 1880: 127 [nomen nudum].

* Columbella (Anachis) Gümbeli nov. form.— Hoernes & Auinger 1880: 102, pl. 11, figs 8a–c.

[ Columbella (Anachis) Gümbeli nov. form.] Varietät A— Hoernes & Auinger 1880: 102, pl. 11, figs 9a–c, 11a–c.

Columbella (Anachis) guembeli R. Hö. — Boettger 1902: 17.

Columbella (Anachis) guembeli Hö. Au. — Boettger 1906: 18.

Anachis terebralis Grat. — Meznerics 1933: 341, pl. 14, figs 9a–b [non Grateloup, 1834].

Pyrene (Anachis) gümbeli Hörnes et Auinger — Csepreghy-Meznerics 1954: 39, pl. 5, fig. 9.

A.[nachis]. (C [ostnachis].) terebralis Grat. — Sieber 1958a: 148 [non Grateloup, 1834].

Anachis (Costoanachis) terebralis Grat. — Sieber 1958b: 148 [non Grateloup, 1834].

Anachis terebralis Grateloup 1834 —Kojumdgieva in Kojumdgieva & Strachimirov 1960: 186, pl. 45, fig. 13 [non Grateloup, 1834].

Columbella (Anachis) terebralis Grateloup, 1847 — Strausz 1966: 295, pl. 34, figs 11–12 [non Grateloup, 1834].

Anachis terebralis (Grateloup, 1834) — Iljina 1993: 97, pl. 13, fig. 3 [non Grateloup, 1834].

Anachis terebralis (Grateloup, 1834) — Bałuk 1995: 239, pl. 33, figs 1–5 [non Grateloup, 1834].

Costoanachis terebralis (Grateloup, 1834) — Landau et al. 2013: 188, pl. 28, fig. 11, pl. 66, fig. 8, pl. 67, fig. 1

Type material. Lectotype (designated herein): NHMW1866 /0001/1025b, Steinebrunn ( Austria), SL: 7.4 mm, MD: 3.1 mm, illustrated in Hoernes & Auinger (1880, pl. 11, figs 8a–c), Figs 4L, 5A 1 –A 2 . Paralectotypes: NHMW1949 /0005/0007, Niederleis ( Austria) , SL: 6.3 mm, MD: 3.8 mm, illustrated in Hoernes & Auinger (1880, pl. 11, figs 9a–c), figs 5B 1 –B 2. NHMW1866 /0001/1025c, Forchtenau ( Austria) , SL: 5.6 mm, MD: 2.7 mm, illustrated in Hoernes & Auinger (1880, pl. 11, figs 11a–c), Figs 5C 1 –C 2 . NHMW2020 /0148/0001, SL: 7.2 mm, MD: 3.1mm, Szob ( Hungary) , Figs 5D 1 –D 2 . NHMW2020 /0148/0002, SL: 5.1 mm, MD: 2.5 mm, Szob ( Hungary) , Figs 5E 1 – E 2 . NHMW2020 /0148/0003, SL: 5.8 mm, MD: 2.6 mm, Szob ( Hungary) , Figs 6A 1 –A 2 . NHMW1887 /0018/0021, Steinebrunn ( Austria) , illustrated in Meznerics (1933, pl. 14, figs 9a–b). NHMW1897 /0015/0297, 35 spec., Szob ( Hungary) .

Additional material. NHMW 2020 /0172/0003 (ex B. Landau coll.), 22 spec., Lăpugiu de Sus ( Romania) ; NHMW 2020 /0173/0001 (ex B. Landau coll.), 5 spec., Coşteiu de Sus ( Romania) .

Revised description. Shell small, squat fusiform, with conical spire and narrowly incised suture. Protoconch dome-shaped, multispiral of 3.5 convex whorls with faint spiral thread just above abapical suture, coinciding in position with lobe of moderately deep sinusigera. Teleoconch of five whorls, with periphery at abapical suture. Spire whorls flat to weakly convex; early teleoconch whorls with prominent, weakly opisthocline, more or less closely set axial ribs, roughly equal in width to their interspaces.Axial sculpture variable in strength and density on penultimate and last whorl, but usually persisting throughout ontogeny. Axial ribs weakly sigmoidal on last whorl. Last whorl regularly convex, with moderately constricted base and short siphonal canal. Spiral sculpture of low spiral cords confined to base and siphonal fasciole. Aperture moderately narrow to narrow. Anal canal indistinctly incised, broad V-shaped; siphonal canal moderately narrow, short. Outer lip with moderately strongly developed internal labial callus pad, with six to eight prominent denticles within, D2 (= second from top) slightly stronger. Columellar callus moderately thickened forming sharply delimited callus rim, with three prominent denticles on middle portion of outer columellar edge.

Shell measurements and ratios. SL: 5.1–7.4 mm, MD: 2.5–3.8 mm, AA: 42–46°, SL/MD: 2.2–2.3, AL/AW: 3.8–4.1, LWH/AH: 1.3–1.4.

Discussion. This species is variable in strength and density of its axial sculpture. In a few specimens the axial ribs fade on the third spire whorl, but reappear on the last whorl ( Figs 5C 1 –C 2 ). Only in very few specimens the last whorl becomes smooth ( Figs 5B 1 –B 2 ). In the majority of specimens, the axial sculpture continues throughout growth. Unfortunately, Hoernes & Auinger (1880) based their new species mainly on these aberrant specimens. For clarification we chose a ‘normally’ sculptured specimen as lectotype and illustrate the variability with additional paralectotypes.

Costoanachis guembeli has been confused with Costoanachis terebralis (Grateloup, 1834) from the early Miocene of the northeastern Atlantic. Specimens from the Aquitanian of the Atlantic early Miocene of the Aquitaine Basin, France differ from the Paratethyan shells in their less convex last whorl, straight axial ribs and the high conical protoconch with strongly convex whorls (see Lozouet 2015; https://science.mnhn.fr/institution/mnhn/ collection/f/item/a53659). Therefore, we refrain from synonymising both species. Specimens from the Tortonian of the northeastern Atlantic, described by Landau et al. (2019) as C. terebralis , are very similar to C. guembeli in sculpture and display an identical protoconch morphology (see Landau et al. 2019 pl. 15, fig. 2). A difference is the presence of an adapical denticle in the aperture of C. guembeli , which is seen in Paratethyan specimens and in shells from the Serravallian of Turkey ( Landau et al. 2013), but is absent in the Tortonian specimens. Thus, the French specimens described by Landau et al. (2019) are probably not conspecific with C. terebralis . They differ in having narrower axial ribs and a very broad U-shaped anal canal. Their taxonomic status will be rectified in Landau et al. (in prep).

Palaeoenvironment. Unknown.

Distribution in Central Paratethys. Badenian (middle Miocene): Carpathian Foredeep: Korytnica ( Poland) ( Bałuk 1995); Vienna Basin: Niederleis, Steinebrunn ( Austria) ( Hoernes &Auinger 1880; Sieber 1958b); Eisenstadt- Sopron Basin: Forchtenau ( Austria) ( Hoernes & Auinger 1880); Cserhát Mountains: Sámsonháza ( Hungary) ( Strausz 1966)

Pannonian Basin: Szob ( Hungary) ( Strausz 1966); Făget Basin: Lăpugiu de Sus, Coşteiu de Sus ( Romania) (own data); Dacian Basin: Opanec ( Bulgaria) (Kojumdgieva in Kojumdgieva & Strachimirov 1960).

Eastern Paratethys. Tarkhanian (middle Miocene): Chadyschensk ( Georgia) ( Iljina 1993). Proto-Mediterranean Sea. Serravallian (middle Miocene): Akpýnar-Pýnarlar, Akboðaz, Lale, Seyithasan,

Yaylasý ( Turkey) ( Landau et al. 2013).

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.

FIGURE 5. A1–A2. Costoanachis guembeli (Hoernes & Auinger, 1880). NHMW1866/0001/1025b, lectotype, Steinebrunn (Austria). B1–B2. Costoanachis guembeli (Hoernes & Auinger, 1880), NHMW1949/0005/0007, paralectotype, Niederleis (Austria). C1–C2. Costoanachis guembeli (Hoernes & Auinger, 1880), NHMW1866/0001/1025c, paralectotype, Forchtenau (Austria). D1–D2. Costoanachis guembeli (Hoernes & Auinger, 1880), NHMW2020/0148/0001, Szob (Hungary). E1–E2. Costoanachis guembeli (Hoernes & Auinger, 1880), NHMW2020/0148/0002, Szob (Hungary).

FIGURE 6. A1–A2. Costoanachis guembeli (Hoernes & Auinger, 1880), NHMW1887/0018/0021, Steinebrunn (Austria). B1–B2. Costoanachis latecostata (Boettger, 1902), SMF 360677, lectotype, Coşteiu de Sus (Romania). C1–C2. Costoanachis latecostata (Boettger, 1902), NHMW2020/0147/0001, Forchtenau (Austria). D1–D2. Costoanachis latecostata (Boettger, 1902), SMF 360679, lectotype of Columbella (Anachis) subcorrugata Boettegr, 1906, Coşteiu de Sus (Romania). E1–E2. Costoanachis latecostata (Boettger, 1902), NHMW1866/0001/1025a, Forchtenau (Austria).