Gregorioiscala ascialis, Harzhauser & Landau, 2025

Harzhauser, Mathias & Landau, Bernard M., 2025, The Epitoniidae (Gastropoda, Epitonioidea) of the Miocene Central Paratethys Sea-an overwhelming diversity, Zootaxa 5630 (1), pp. 1-142 : 63-64

publication ID	https://doi.org/10.11646/zootaxa.5630.1.1
publication LSID	lsid:zoobank.org:pub:89462472-D932-4255-880F-C6EF15220A31
persistent identifier	https://treatment.plazi.org/id/03D787A4-FFDB-FFDB-FF3F-FA57FE82913D
treatment provided by	Plazi
scientific name	Gregorioiscala ascialis
status	sp. nov.

Treatment

Gregorioiscala ascialis sp. nov.

Figs 21H View FIGURE 21 , 22F View FIGURE 22 1 –F View FIGURE 1 2 View FIGURE 2

Type material. Holotype, NHMW 1862 View Materials /0029/0082, SL: 9.0 mm, MD: 3.6 mm, Rudice ( Czech Republic), Figs 21H View FIGURE 21 , 22F View FIGURE 22 1 –F View FIGURE 1 2 View FIGURE 2 .

Type locality. Rudice ( Czech Republic), Carpathian Foreland Basin .

Type stratum. Unknown.

Age. Middle Miocene, middle Badenian (Langhian).

Etymology. From ascia (Latin for ax), referring to the shape of the last whorl.

Diagnosis. Shell small, solid, moderately slender, turreted, of low, strongly convex whorls with broad, prominent axial ribs and last whorl with two prominent, wing-like varices placed at periphery, terminal varix with short, prominent shoulder spine.

Description. Shell small, solid, moderately slender, turreted (apical angle ~23°). Protoconch unknown. Teleoconch of about nine relatively low whorls. Whorl profile of early whorls with moderately steep, weakly concave subsutural ramp, angled periphery placed below mid-whorl. Later teleoconch whorls more convex below suture, with convex periphery placed mid-whorl. Suture deeply impressed, weakly undulating. Sculpture of moderately widely spaced, very prominent, convex, weakly opisthocline axial ribs, about equal in width to their interspaces, partly aligned axially (9: 9: 10), most prominent along periphery, slightly weakening over subsutural ramp. Spiral sculpture of numerous subobsolete spiral cords separated by slightly narrower interspaces. Last whorl broad, attaining ~30% of total height, bearing two prominent, wing-like varices placed at periphery, terminal varix with short, prominent spine, basal angulation delimited by very prominent, broad peribasal cord, axial ribs terminate at cord, base weakly concave, smooth. Aperture subcircular, columella weakly convex. Outer lip strongly thickened by terminal varix. Columellar and parietal callus forming continuous, narrow rim, detached from base. Peristome duplex. Umbilicus reduced to narrow chink. Finely pitted intritacalx typical for genus not preserved.

Discussion. The Paratethyan species is morphologically very close to the Pliocene Mediterranean Gregorioiscala abrupta ( De Cristofori & Jan, 1832) from which it differs in the much larger adult size of the Pliocene species (17 mm; based on Estepona specimens fide Landau et al., 2006: 48), less angled whorls, the presence of a shoulder spine and the comparatively narrower basal disc (see Pinna & Spezia, p. 159, pl. 44, fig. 2; Landau et al. 2006: 48, pl. 14, figs 8–9). The extant north-eastern Atlantic Gregorioiscala pachya (Locard, 1897) is also slenderer and lacks prominent varices on the last whorl ( Cossmann 1912: pl. 4, figs 1–2; Bouchet & Warén 1986: figs 1119–1121, 1254–1255).

Paleoenvironment. Probably middle to outer neritic based on the co-occurring assemblage. (own data M.H.). This interpretation would fit to the habitat of extant species ( Bouchet & Warén 1986).

Distribution in Central Paratethys. Badenian (Middle Miocene): Carpathian Foreland Basin: Rudice ( Czech Republic) (hoc opus).

Genus Hemiacirsa de Boury, 1890

Type species. Turbo lanceolatus Brocchi, 1814 ; original designation by de Boury (1890: 268). Pliocene, Italy.

Diagnosis. “ Thick shell; quite large; very narrow, clavoid shape; spire long, turriculate; whorls numerous, conjoint, almost flat or only slightly convex, separated by linear suture; ornamentation composed of axial ribs, thick , barely prominent, fairly wide apart, crossed by more or less close-set spiral grooves. Last whorl less than one-sixth of total length, subangular at periphery of base, which is mediocrely convex and simply furrowed, ribs replaced by a few irregular radiating folds; center imperforate. Aperture oval, slightly narrowed posteriorly; peristome duplex, inner layer fairly calloused and continuous, outer layer thin and discontinuous; peristome slightly oblique, very broadly bordered on the outside; columellar margin slightly excavated, thickened below, slightly sloping forward on the neck.” (translated from Cossmann 1912: 97–98).

Discussion. Hemiacirsa was treated as subjective junior synonym of Acirsa Mörch, 1857 by Bouchet & Warén (1986) and MolluscaBase eds (2024f). Herein, we resurrect Hemiacirsa based on its very slender outline, weakly impressed suture, subcylindrical to weakly convex whorls, and prominent axial ribs on early teleoconch whorls. The type species of Acirsa , A. borealis ( Lyell, 1841) differs distinctly from any of the species attributed here to Hemiacirsa in its wider apical angle, more convex whorls that give the shell quite a different profile, and weaker axial sculpture. The genus experienced a major radiation during the Miocene and comprises many species, such as: Hemiacirsa duvergieri (de Boury in Cossmann, 1912 (Burdigalian, France), H. prolanceolata ( Sacco, 1891) (Burdigalian, Italy), H. cristulosa ( Sacco, 1891) , H. convexiuscula ( Sacco, 1891) , H. taurolanceolata ( Sacco, 1891) and H. varicosocylindrica ( Sacco, 1891) (Burdigalian or Langhian, Italy), H. tauroprysmatica ( Sacco, 1891) (Langhian, Italy), H. miocenica ( Seguenza, 1880) (Langhian, Austria; Tortonian, Italy), H. abiaeformis sp. nov., H. drevermanni (de Boury in Cossmann, 1912), H. incusa sp. nov. and H. superelongata sp. nov. (Langhian/ Badenian, Austria, Hungary, Romania), H. lanceolata ( Brocchi, 1814) (Tortonian to Pliocene, Italy). Hemiacirsa became extinct during the Pleistocene ( Cerulli-Irelli 1914) [note that Proto-Mediterranean Miocene species will need revision].