Hemiacirsa abiaeformis, 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 : 65

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-FFA5-FFA4-FF3F-FF2EFDD29152
treatment provided by	Plazi
scientific name	Hemiacirsa abiaeformis
status	sp. nov.

Treatment

Hemiacirsa abiaeformis sp. nov.

Figs 23A–C View FIGURE 23 , 24A–B View FIGURE 24

Scalaria lanceolata Brocc.— Hörnes 1848: 22 [non Hemiacirsa lanceolata ( Brocchi, 1814) ].

Scalaria lanceolata Brocc.—Hörnes 1856: 481 , pl. 46, fig. 14 [non Hemiacirsa lanceolata ( Brocchi, 1814) ].

Acirsa (Hemiacirsa) lanceolata Brocchi View in CoL var.— Csepreghy-Meznerics 1956: 389, pl. 3, figs 36–37 [non Hemiacirsa lanceolata Brocchi, 1814 ].

A [cirsa]. (H [emiacirsa].) lanceolata miocenica (Seg.) — Sieber 1958: 129 [non Hemiacirsa miocenica ( Seguenza, 1880) ].

Acirsa (Hemiacirsa) aff. lanceolata Brocchi— Strausz 1966: 180 View in CoL , pl. 1, figs 41–42.

Acirsa (Hemiacirsa) lanceolata prolanceolata Sacco — Csepreghy-Meznerics 1969a: 21, pl. 4, fig. 5 [non Hemiacirsa prolanceolata ( Sacco, 1891) ].

Type material. Holotype, NHMW 2024 View Materials /0281/0001, SL: 23.4 mm, MD: 4.9 mm, Baden-Sooss ( Austria), Figs 23A View FIGURE 23 1 – A View FIGURE 1 2 View FIGURE 2 , 24A View FIGURE 24 . Paratypes, NHMW 2024 View Materials /0281/0002, SL: 22.0 mm , MD: 5.3 mm, Baden-Sooss ( Austria), Figs 23C View FIGURE 23 1 –C View FIGURE 1 2 View FIGURE 2 , 24B View FIGURE 24 . NHMW 1866 View Materials /0015/1189, SL: 20.6 mm , MD: 4.6 mm, Baden ( Austria), illustrated in Hörnes (1856: pl. 46, fig. 14), Figs 23B View FIGURE 23 1 –B View FIGURE 1 2 View FIGURE 2 .

Type locality. Baden-Sooss ( Austria), Vienna Basin .

Type stratum. Baden Formation.

Age. Middle Miocene, middle Badenian (Langhian).

Etymology: From Picea abies (spruce), referring to the conifer-like outline.

Diagnosis. Large, slender conical shell of about 13 weakly convex whorls with periphery close above abapical suture, prominent, moderately close-set axial ribs and prominent spiral cords in axial interspaces, aperture ovate with simple peristome differing from its congeners in its comparatively wide apical angle and prominent axial ribs.

Description. Large, slender conical, slightly cyrtoconoidal shell (apical angle ~15–17°). Protoconch unknown. Teleoconch of about 13 whorls. Early teleoconch whorls strongly convex with prominent, orthocline, convex axial ribs separated by narrower interspaces. Later whorls weakly convex with delicate subsutural cord, weakly concave subsutural ramp and convex periphery placed close above abapical suture. Suture superficially incised, slightly undulating. Moderately close-set, prominent, orthocline to weakly opisthocyrt axial ribs, weakening slightly over subsutural ramp, not strictly aligned axially. Axial interspaces of roughly equal width to ribs bearing numerous spiral cords separated by narrow grooves (8/10: 10/12: 10/11). Spiral cord at abapical suture more prominent. Spiral sculpture weak to subobsolete over ribs. About one slightly broader axial rib per whorl forming indistinct varix. Last whorl attaining ~27% of total height, with distinct, rounded basal angulation delimited by one or two slightly more prominent peribasal cords, followed by up to 12 cords on flattened to weakly convex base. Aperture elongate ovate with weakly concave columella, widely angled adapically. Outer lip thin. Columellar callus forming moderately broad rim, detached from base, parietal callus forming narrow rim. Peristome simple. Umbilicus reduced to very narrow chink.

Discussion. Hemiacirsa abiaeformis sp. nov. was confused with Hemiacirsa lanceolata ( Brocchi, 1814) by Hörnes (1856), with Hemiacirsa miocenica ( Seguenza, 1880) by Sieber (1958) and with Hemiacirsa prolanceolata ( Sacco, 1891) by Csepreghy-Meznerics (1969a). It differs from all these species in its wider apical angle, convex whorl periphery placed close above the abapical suture and the prominent, regular axial ribs. Hemiacirsa prolanceolata ( Sacco, 1891) , from the Burdigalian or Langhian of the Colli Torinese ( Italy), is smaller, has sharper axial ribs and a wider aperture (see Sacco 1891: pl. 2, figs 98 a–b; Ferrero Mortara et al. 1984: pl. 6, fig. 15).

Paleoenvironment. Occurrences in the Baden Formation of the Vienna Basin suggest middle to outer neritic settings in up to 250 m water depth ( Kranner et al. 2021) but specimens from Szob ( Hungary) might rather drive from shallow water environments.

Distribution in Central Paratethys. Badenian (Middle Miocene): Vienna Basin: Baden, Bad Vöslau ( Austria) (Hörnes 1856); Pannonian Basin: Szob ( Hungary) ( Csepreghy-Meznerics 1956); Bükk Mountains: Borsodbóta ( Hungary) ( Csepreghy-Meznerics 1969a).