Hastula translata

Hastula translata (Sacco, 1891)

Figs 3D, 8A–B

Terebra striata Bast. — Hilber 1879: 421, pl. 1, figs 4a–c.

Terebra (Hastula) striata Bast. — Hoernes & Auinger 1880: 110, pl. 12, figs 21a–c.

* [Terebrum (Hastula) algarbiorum] var. translata Sacc. — Sacco 1891a: 56 [pro. Terebra (Hastula) striata sensu Hoernes & Auinger 1880: pl. 12, figs 21a–c].

Type material. Holotype, NHMW 2023 /0301/0001, SL: 11.6 mm, MD: 3.1 mm, Pöls (Austria), illustrated in Hoernes & Auinger (1880: pl. 12, figs 21a–c), Figs 3D, 8A 1 –A 2.

Illustrated material. NHMW 2023/0301/0002, SL: 9.9 mm, MD: 3.0 mm, Pöls (Austria), illustrated in Hilber (1879: pl. 1, figs 4a–c), Figs 8B 1 –B 2. No additional material is available.

Revised description. Small, moderately slender shell of up to nine teleoconch whorls with slightly cyrtoconoid spire profile; apical angle ~26°, decreasing to ~10° on late teleoconch whorls. Protoconch high conical of about 3 convex whorls. Early teleoconch whorls conical, with prominent, slightly opisthocline axial ribs, separated by narrower interspaces. No subsutural band. Later teleoconch whorls subcylindrical with narrowly incised suture, faintly gradate profile. Abapically, ribs narrow mid-whorl and become obsolete or almost so, reappearing faintly and broader again just above suture. Last whorl subcylindrical, high, ~42% of total height with rounded basal angulation.

Axial ribs strengthening over basal angulation. Base weakly contracting. Fasciole broad, flat, delimited by low carina. Aperture narrow. Columella twisted, weakly excavated in adapical half. No columellar fold. Columellar callus forming thin, broad rim, poorly delimited from base. Anal canal narrowly incised. Outer lip thin. Siphonal canal short, wide, shallowly notched.

Discussion. Sacco (1891a) established this species as ‘variety’ of the Tortonian Hastula algarbiorum (Pereira da Costa, 1867). This species differs mainly in its slightly more gradate spire and especially the specimens illustrated by Davoli (1977) display a strongly reduced axial sculpture and are thick-shelled (see Pereira da Costa, 1867: 13, figs 11–12; Sacco 1891a: pl. 2, figs 56–60; Davoli 1977: pl. 1, figs 4–5, 17–18). More specimens of Hastula translata would be needed to evaluate if these fall within the range of variability of H. algarbiorum. Hastula translata was confused by Hilber (1879) and Hoernes & Auinger (1880) with Hastula striata (de Basterot, 1825), from the Burdigalian of France. The Paratethyan species differs from H. striata in the distinctly less slender outline of its shell, lower spire, and weaker axial ribs at the abapical suture (see Peyrot 1931: pl. 10, figs 49–50; Glibert 1952a: pl. 14, fig. 1a). Bałuk (1997) treated the holotype of this species as Hastula cinereides (Hoernes & Auinger, 1880) [= Hastula duboisiana (d’Orbigny, 1852)], but Hastula translata differs from H. cinereides in a much smaller size, slenderer shell (at same growth stage) and more prominent axial ribs. Hastula hungarica Csepreghy-Meznerics, 1954 has similar sculpture but is much more obese and has a higher last whorl.

Paleoenvironment. Coastal marine, inner neritic paleoenvironments of a protected embayment.

Distribution in Central Paratethys. Badenian (Middle Miocene): Styrian Basin: Pöls (Austria) (Hoernes & Auinger 1880).

Genus Hastulopsis Oyama, 1961

Type species. Terebra melanacme E.A. Smith, 1875; original designation by Oyama (1961: 161). Present-day, Japan. Revised diagnosis. “ Shell small to medium-sized (to 60 mm), shiny, faintly axially ribbed, with numerous fine spiral incisions. Subsutural band generally not spirally decorated, bordered by relatively deep incision.” (Fedosov et al. 2020: 379, see also Terryn 2007).

Discussion. In the European Neogene there exists a group of species with medium-sized shells characterized by a weak to subobsolete subsutural band and a change in axial sculpture during ontogeny, starting with prominent axial ribs on early teleoconch whorls, which are replaced by weak ribs or folds or become entirely subobsolete on last teleoconch whorls. This group comprises ‘Terebra’ excostellata Sacco, 1891a, ‘Terebra’ exilis Bell, 1871, ‘Terebra’ fuchsii (Hoernes, 1875), ‘Terebra’ hoernesi Beyrich, 1854, ‘Terebra’ pedemontana Sacco, 1891, and ‘Terebra’ striatellata (Sacco, 1891). These species have variously been placed in Hastula, Terebra and Strioterebrum in the literature (e.g., Sieber 1958; Wienrich 2006; Ceulemans et al. 2018). The general shell shape, however, differs clearly from the slender, multi-whorled Terebra (as defined by Fedosov et al. 2020). The group lacks the wide basal lip of Hastula and differs from that genus in the longer, narrower siphonal canal. Strioterebrum has a distinct subsutural band, delimited by a spiral grove and its siphonal canal is less twisted. In contrast, these species are morphologically very similar to living species of Hastulopsis, such as Hastulopsis blanda (Deshayes, 1859), H. gotoensis (E.A. Smith, 1879), H. masirahensis Terryn & Rosado, 2016, H. melanacme (E.A. Smith, 1875), and H. mirbatensis Terryn & Rosado, 2016. Hastulopsis suspensa (E.A. Smith, 1904) differs from that group by the presence of delicate spiral threads but is otherwise also very similar. Therefore, we propose to place these Neogene European species in Hastulopsis, which has not been recorded so far from the Neogene of the Circum-Mediterranean Region. These Neogene European species are also reminiscent of the pervicaciine genus Partecosta Dance & Eames, 1966 [type species Strioterebrum wilkinsi Dance & Eames, 1966 (= Terebra fuscobasis E.A. Smith, 1877)]. That genus also has predominant axial sculpture and lacks a distinct subsutural band but differs from Hastulopsis in its short and wide siphonal canal and the wide, convex basal outer lip.

All species currently placed in Hastulopsis by Fedosov et al. (2020) occur in the Indo-West Pacific.