Euthriofusus irpus

Harzhauser, Mathias & Landau, Bernard M., 2024, The Colubrariidae, Eosiphonidae, Melongenidae, Pisaniidae, Prodotiidae and Tudiclidae (Gastropoda, Buccinoidea) of the Miocene Paratethys Sea, Zootaxa 5427 (1), pp. 1-110 : 63-65

Euthriofusus irpus ( De Gregorio, 1885 a)

Figs 32A–C

[ Fasciolaria ] burdigalensis Bast. — Hörnes 1848: 19 [non Euthriofusus burdigalensis (de Basterot, 1825) ].

Fusus Burdigalensis Bast. —Hörnes 1853: 296, pl. 32, figs 13–14 [non Euthriofusus burdigalensis (de Basterot, 1825) ].

* [ Tudicla Burdigalensis Bast. ] irpus de Greg. — De Gregorio 1885 a: 49 [pro Pyrula rusticula sensu Hörnes (1853: pl. 32, figs 13–14).

Fasciolaria (Tudicla) burdigalensis Bast. —Hoernes & Auinger 1890: 264 [non Euthriofusus burdigalensis (de Basterot, 1825) ].

Euthriofusus burdigalensis (Defrance) — Sieber 1937: 143 [non Euthriofusus burdigalensis (de Basterot, 1825) ].

E [uthriofusus] (E [uthriofusus].) burdigalensis (Bast.) — Sieber 1958: 152 [non Euthriofusus burdigalensis (de Basterot, 1825) ].

Euthriofusus (Euthriofusus) burdigalensis (Basterot) — Schultz 1998: 68, pl. 27, figs 6–7 [non Euthriofusus burdigalensis (de Basterot, 1825) ].

non Euthriofusus burdigalensis Bast. — Strausz 1954: 30, pl. 8, figs 156a–b [= Bolinus sp. ].

non Euthriofusus burdigalensis Defrance (in Basterot), 1825— Strausz 1966a: 355, pl. 54, figs 5–8 [= Bolinus sp. ].

non Euthriofusus burdigalensis ( Basterot, 1825) — Kovács 2022: 93, figs 94–95 [= Bolinus sp. ].

non Euthriofusus cf. burdigalensis ( Basterot, 1825) — Kovács & Vicián 2023: 254, figs 13R [= Bolinus sp. ].

Type material. Lectotype (designated herein): NHMW 1851 /0002/0045a, SL: 62.8 mm, MD: 28.6 mm, Grund ( Austria), illustrated in Hörnes (1853: pl. 32, fig 14), Figs 32A 1 –A 2 . NHMW 1851 /0002/0045b, SL: 65.3 mm, MD: 33.1 mm, Grund ( Austria), Figs 32B 1 –B 2 . NHMW 1855 /0045/0722a, SL: 66.9 mm, MD: 33.1 mm, Grund ( Austria), illustrated in Hörnes (1853: pl. 32, fig 13), paralectotype, Figs 32C .

Additional material. 13 spec., NHMW 1851 /0026/0041, Grund ( Austria) ; 7 spec., NHMW 1851 /0002/0045, Grund ( Austria) ; 7 spec., NHMW 1855 /0045/0722b, Grund ( Austria) ; 4 spec., NHMW 2023 /0339/0001, Guntersdorf ( Austria) ; 3 spec., NHMW 2023 /0340/0001, Guntersdorf ( Austria) .

Description. Large club-shaped species of up to six teleoconch whorls; apical angle 50–55°. Protoconch unknown. Early teleoconch whorls distinctly angled mid-whorl, with thin, narrow subsutural collar and broad, faintly concave subsutural ramp. Suture incised, weakly undulating. On early whorls axial ribs represented by prominent rounded tubercles at shoulder, fading over subsutural ramp and extending below to suture. Abapically ribs weaken on fourth to fifth teleoconch whorl, reduced to indistinct tubercles at shoulder. Spiral sculpture of several weak spiral cords over subsutural ramp and three prominent spiral cords below shoulder with secondary cords intercalated (spiral sculpture of earliest teleoconch whorls abraded in all available specimens); spirals of later teleoconch whorls forming broad, flattened cords separated by narrow interspaces (about 13–15 on penultimate whorl). Last whorl high, attaining 77–80% of total height, with broad, slightly convex to slightly concave subsutural ramp, inflated below angled shoulder, base convex, strongly constricted; spiral sculpture of broad, flattened cords, subobsolete over subsutural ramp, moderately prominent or reduced along periphery and prominent over base, weak to subobsolete over siphonal fasciole. Aperture elongate pyriform, 65% of total height. Columellar callus weakly thickened, forming narrow rim, sharply delimited, thinner and adherent in parietal area. Columella smooth, broadly and weakly excavated, with faint convexity marking transition to siphonal canal. Anal canal narrowly incised, accentuated by small parietal denticle. Outer lip thin with numerous very short lirae starting slightly behind peristome. Shoulder of last whorl usually corresponding to narrow notch in aperture. Siphonal canal extraordinarily long, narrow, straight or more or less distinctly deflected to the left.

Discussion. Lozouet (2001) emphasized the importance of the protoconch to distinguish the northeastern Atlantic Euthriofusus burdigalensis -complex. This feature is not available for the Paratethyan species, but other conchological features allow a clear separation from French species. Euthriofusus burdigalensis (de Basterot, 1825) , from the Early Miocene of Saucats ( France) in the collections of the NHMW, differs from Euthriofusus irpus ( De Gregorio, 1885 a) in its prominent spiral cords, which are wider spaced and convex. The last whorl of the French specimens is less angulated and lacks the notch in the outer lip. Euthriofusus cf. burdigalensis (de Basterot, 1825) , from the Early Miocene of Saint-Paul-lès-Dax ( France), differs quite distinctly in its much stronger spiral sculpture, relatively wider last whorl and much more prominent and longer lirae within the outer lip (see Lozouet 2021: pl. 43, figs 1–6). Euthriofusus peyreirensis Peyrot, 1928 , from the Late Oligocene of Peyrehorade ( France), is comparatively high-spired and has widely spaced and prominent spiral cords on the last whorl (see Lozouet 2021: pl. 43, figs 7–10). The Late Oligocene Euthriofusus argillensis Lozouet, 2021 has a fusiform outline, prominent axial ribs and prominent spiral cords; as already discussed by Lozouet (2021), its placement in Euthriofusus will need verification. Euthriofusus hoernesi Peyrot, 1928 , from the Serravallian of Salles ( France), is a fusiform species with reduced sculpture. It is close to Euthria virginea (Grateloup, 1833) and unrelated to the Euthriofusus burdigalensis - complex (see Peyrot 1928: pl. 6 figs 17–20). Euthriofusus burdigalensis inflatonodosa Sacco, 1904 and Euthriofusus burdigalensis acutopernodosa Sacco, 1904 , both from the Early Miocene of the Colli Torinesi ( Italy), are based on fragmentary specimens and their status needs revision. Both are distinguished from Euthriofusus irpus by the convex last whorl ( Euthriofusus burdigalensis inflatonodosa ) and the high spire and narrower last whorl ( Euthriofusus burdigalensis acutopernodosa ) (see Sacco 1904: pl. 8, figs 7, 8).

Specimens described as Euthriofusus burdigalensis by Strausz (1954, 1966), Kovács (2022) and Kovács & Vicián (2023) are muricids.

Paleoenvironment. Shallow marine, inner neritic. At the locality Grund fossiliferous channel fills, which formed in middle to outer neritic environments bear allochthonous assemblages uniting coastal-mudflat faunas with inner neritic ones ( Zuschin et al. 2005; Roetzel 2009).

Distribution in Central Paratethys. Badenian (Middle Miocene): North Alpine Foreland Basin: Grund, Guntersdorf ( Austria) (hoc opus).

Genus Euthria J.E. Gray, 1850

Type species. Fusus lignarius Chiaje [= Euthria cornea ( Linnaeus, 1758) ]; original designation by J.E. Gray (1850: 67), subsequently Murex corneus Linnaeus, 1758 fixed as type species by Petit (2012: 99) under Art. 70.4. Present-day, Mediterranean Sea.

Original diagnosis. J.E. Gray (1850) did not provide any diagnosis or description.

Revised diagnosis. “Shell fusiform, spire turreted, canal short, broad, recurved, with smooth whorls or obsoletely litrate, plicate-costate only above, usually excavated below the suture. Aperture ovate, above sinuous or subcanaliculate, outer lip thick, denticulate within.” ( Kobelt 1880: 219; translated from Latin).

Discussion. This genus comprises moderately fusiform species with a large, convex, often slightly inflated last whorl. A change of sculpture from prominent axial ribs overrun by several spiral cords on early teleoconch to almost smooth whorls during ontogeny is typical. A weakly concave subsutural ramp causes the characteristic outline; a faint shoulder, low, broad axial swellings or blunt nodes may occur at the shoulder. The columella is usually distinctly excavated and frequently bears a denticle at the junction with the siphonal canal. A parietal denticle may be present, but anal denticle is lacking. The outer lip is wide, usually thinning towards the peristome and bears denticles or lirae. The siphonal canal is quite variable, ranging from moderately short to long, always deflected to the left and often recurved.

Euthria is represented in the Mediterranean Sea and the eastern Atlantic down to Angola ( Schoenherr & Rolán 2017) with a remarkable center of diversity around the Cape Verde Islands from where more than 22 endemic species have been described ( Fraussen & Swinnen 2016). Several species have been recorded also from the Indo-West Pacific Region (e.g., Fraussen & Stahlschmidt 2020a). The Paratethyan occurrences suggest a considerable autochthonous diversity because most records of Proto-Mediterranean Neogene species in the Paratethyan basins are based on misidentifications (see below).

Figures

FIGURE 1. Measurements for shell morphology; AA: apical angle, SL: shell length, MD: maximum diameter, LWH: last whorl height, AH: aperture height, AL: aperture length, AW: aperture width.

FIGURE 2. Colubraria subobscura (Hoernes & Auinger, 1884). A1–A3. NHMW 1854/0035/0170, paralectotype, Lăpugiu de Sus (Romania). B1–B2. NHMW 1859/0037/0018a, paralectotype, Lăpugiu de Sus (Romania). C1–C3. NHMW 1865/0001/0183, paralectotype, Lăpugiu de Sus (Romania). D1–D2. NHMW 1859/0037/0018b, paralectotype, Lăpugiu de Sus (Romania). E1–E3. NHMW 1874/0025/0021, lectotype, Lăpugiu de Sus (Romania). F1–F2. NHMW 2023/0338/0001, paralectotype, Lăpugiu de Sus (Romania).

FIGURE 32. A1–A2. Euthriofusus irpus (De Gregorio, 1885a), NHMW 1851/0002/0045a, holotype, Grund (Austria). B1–B2. Irpus (De Gregorio, 1885a), NHMW 1851/0002/0045b, paratype, Grund (Austria). C. NHMW 1855/0045/0722a, paratype, Grund (Austria).