Hastulopsis fuchsii ( Hoernes, 1875 )

Harzhauser, Mathias & Landau, Bernard M., 2023, The auger snails (Gastropoda, Conoidea, Terebridae) of the Miocene Paratethys Sea, Zootaxa 5385 (1), pp. 1-70 : 21-23

Hastulopsis fuchsii ( Hoernes, 1875)

Figs 10A–C

Terebra pertusa — Hörnes 1853: 190 [non Myurella pertusa (von Born, 1778) ].

* Terebra Fuchsii nov. sp. — Hoernes 1875: 348, pl. 12, figs 2a–b.

Terebra (Acus) Fuchsi R. Hoern. — Hoernes & Auinger 1880: 108, pl. 12, figs 12a–b.

Terebra (Terebra) fuchsi R. Hoernes, 1875 — Steininger 1973: 448, pl. 9, fig. 5.

Terebra fuchsii Hoernes, 1875 —Steger et al. (submitted), fig. 13.

Type material. Syntypes: GBA 1875 /0001/0007/01, SL: 33.6 mm, MD: 9.3 mm; Ottnang ( Austria) Figs 10A 1 –A 2 . GBA 1875 /001/007/03, SL: 17.7 mm, MD: 5.5 mm, Figs 10B 1 –B 2 . GBA 1875 /001/007/04, SL: 20.7 mm, MD: 5.5 mm, Figs 10C 1 –C 2. A lectotype will be designated in the revision of the mollusk fauna from Ottnang by Steger et al. (submitted). No additional material is available.

Revised description. Medium sized, moderately slender conical shell of up to 11 teleoconch whorls; apical angle ~18–20°. Protoconch unknown. Early teleoconch whorls weakly convex with prominent, orthocline to weakly prosocline axial ribs. Subsutural band narrow, weak, represented by spiral row of weak beads. Later whorls subcylindrical with weakly gradate spire profile. Dense, weakly opisthocyrt axial ribs or folds on later whorls. Last whorl high, subcylindrical, ~41% of total height, with rounded basal angulation. Base moderately contracted. Fasciole weak. Aperture narrowly pyriform. Columella twisted, excavated in adapical half. Columellar callus forming broad, thin rim, indistinctly delimited from base. Anal canal narrowly incised. Outer lip thin (only partly preserved). Siphonal canal moderately long, narrow, moderately twisted, slightly deflected to the left.

Discussion. This species is reminiscent of the Middle Miocene Hastulopsis excostellata ( Sacco, 1891a) but differs in its lower spire and the more prominent and wider-spaced axial ribs on early teleoconch whorls. Steger et al. (submitted) emphasized the prominent axial ribs of the syntype illustrated herein as Figs 10C–C and doubted that it was conspecific with the specimen illustrated by Hoernes (1875) ( Figs 10A–A ). The sculpture of the early whorls, however, is very similar in both specimens (at same scale) and we assume that both specimens represent morphs of the same species. Moreover, the Early Miocene mollusk fauna of Ottnang ( Austria) is characterized by a relatively low diversity (see Hoernes 1875; Steger et al. submitted), probably due to the peculiar environmental conditions in a tide and storm dominated shelf ( Grunert et al. 2012), and it would be surprising that two closely related species co-occurred.

Paleoenvironment. Tide- and storm-influenced outer-middle neritic depositional settings ( Grunert et al. 2012).

Distribution in Central Paratethys. Ottnangian (Early Miocene): North Alpine Foreland Basin: Ottnang ( Austria) ( Hoernes & Auinger 1880; Steininger et al. 1971).

Genus Oxymeris Dall, 1903

Type species. Buccinum maculatum Linnaeus, 1758 ; subsequent designation by Dall (1908: 125). Present-day, Indo-West Pacific.

Note. Dall (1903: 951) introduced the name Oxymeris “ for the section of Terebra , commonly called Acus ” but did not designate a type species, which he did in Dall (1908: 125).

Original diagnosis. No diagnosis or description was given by Dall (1903).

Revised diagnosis. “ Medium-sized to large, reaching 273 mm; weakly sculptured, typically with orthoconoid spire and rather wide aperture. Protoconch multispiral, 3–3.75 whorls. Sculpture of subsutural band, smooth or with regular crenulations; juvenile sculpture often consisting of axial ribs. Whorls flattened in outline; last adult whorl inflated; siphonal canal short, stout. Aperture wide, elliptic to rounded ” ( Fedosov et al. 2020: 372). In addition, Fedosov et al. (2020: 372) emphasized that most Oxymeris species can be recognized by the complete lack of axial sculpture other than growth lines, except for O. crenulata ( Linnaeus, 1758) .

Discussion. Oxymeris is represented in the European Neogene by O. buiturica ( Moisescu, 1955a) , O. fuscata ( Brocchi, 1814) , O. modesta ( Defrance, 1829) , O. plicaria (de Basterot, 1825) and O. transleithana nov. sp. European fossil species differ from present-day species included by Fedosov et al. (2020) in Oxymeris in having more prominent axial sculpture, especially on early and mid-spire whorls; and some species have a deeper suture (e.g., O. buiturica , O. modesta ). Oxymeris plicaria , O. modesta and O. fuscata have been placed in various combinations with Terebra and Oxymeris in Subula Schumacher, 1817 by most authors (e.g., Strausz 1966; Csepreghy-Meznerics 1972; Bohn-Havas 1973; Bałuk 1997; Schultz 1998; Harzhauser 2002; Landau et al. 2013). Subula , however, is an unnecessary replacement name for Terebra ( Fedosov et al. 2020: 367) .

Figures

FIGURE 1. Measurements for shell morphology, spire profiles and types of siphonal canals; AA: apical angle, MD: maxium diameter.

FIGURE 2. Fusoterebra terebrina (Bellardi & Michelotti, 1840). A1–A2. NHMW 1997z/0178/1787, Walbersdorf (Austria). B1–B2. NHMW 1997z/0178/1787, Walbersdorf (Austria). C1–C2. NHMW 1997z/0178/1787, Walbersdorf (Austria). D1–D2. NHMW 1846/0037/0121, Baden (Austria), lectotype of Terebra fusiformis Hörnes 1852.F. NHMW 1866/0001/1055, Forchtenau (Austria), holotype of Terebra bigranulata Hoernes & Auinger, 1880. E1–E2. NHMW 2023/0292/0001, Baden Sooss (Austria).

FIGURE 10. Hastulopsis fuchsii (Hoernes, 1875). A1–A2. Syntype, GBA 1875/0001/0007/01, Ottnang (Austria). B1–B2. Syntype, GBA 1875/001/007/03, Ottnang (Austria). C1–C2. Syntype, GBA 1875/001/007/04, Ottnang (Austria).