Fraudifusinus, Harzhauser & Landau & Vermeij, 2024

Harzhauser, Mathias, Landau, Bernard M. & Vermeij, Geerat J., 2024, The Dolicholatiridae and Fasciolariidae (Gastropoda, Buccinoidea) of the Miocene Paratethys Sea, Zootaxa 5470 (1), pp. 1-92 : 42-43

Fraudifusinus nov. gen.

Type species. Fusus crispoides Kittl 1887 ; Badenian (Middle Miocene), Austria .

Diagnosis. Medium-sized, moderately slender fusiform with conical spire of convex to weakly shouldered whorls with deeply incised suture, sculpture of broad, widely spaced axial ribs overrun by prominent primary and secondary spiral cords, last whorl strongly convex with strongly constricted base and long siphonal canal, columella with few columellar denticles, anal canal incised, outer lip with few or more prominent denticles at transition from outer lip to siphonal canal.

Description. Medium-sized, moderately slender fusiform of about seven to eight teleoconch whorls. Apical angle ~40–45°. Protoconch high conical of 3.5 moderately convex whorls. Axial sculpture of broad, prominent ribs separated by wider interspaces crossed by few secondary spiral cords on subsutural ramp; early whorls with three primary spiral cords, adapical cord over subsutural ramp weaker, second cord delimiting shoulder. Variable number of secondary cords intercalated between primaries. Whorls convex or slightly shouldered below mid-whorl; suture deeply incised, undulating. Last whorl convex, attaining 56–65% of total height with seven to eight axial ribs on last whorl, fading over subsutural ramp and base. Base strongly constricted. Base and siphonal canal with prominent primary spiral cords and variable number of secondary cords intercalated. Fasciole indistinct. Aperture moderately narrowly pyriform. Columella moderately excavated in adapical half with few denticles of variable strength. Parietal denticle may be present. Anal canal distinctly incised. Outer lip thickened by terminal varix. Up to ten short or moderately long lirae, very variable in strength and number even within species. Two or more prominent denticles at transition to siphonal canal. Siphonal canal moderately long, moderately narrow, straight, weakly deflected to the left.

Etymology. A combination of the Latin fraus (= fraud) and Fusinus , because the genus looks deceptively similar to Fusinus and its allies.

Included species. Fusus crispoides Kittl 1887 ; Fraudifusinus grundensis nov. sp.; Fraudifusinus pseudocrispoides nov. sp.

Stratigraphic and geographic range. Badenian (Middle Miocene) of the Central Paratethys Sea.

Paleoenvironment. Inner neritic to outer neritic environments.

Discussion. Fraudifusinus nov. gen. might be closer to Takashius Kantor, Fedosov, M. A. Snyder & Bouchet, 2022 , than to other Fusininae genera based on similarities in apertural features. However, they are distinguished by the well-defined, strongly raised axial ribs in Takashius and its more uniform spiral sculpture. Moreover, Takashius lacks denticles at the transition from the outer lip to siphonal canal. Fraudifusinus is similar to Pseudofusus Monterosato, 1884 [type species Murex rostratus Olivi, 1792 ; present day, Mediterranean Sea] but differs in the columellar denticles and the peculiar denticles at the transition from outer lip to siphonal canal. Moreover, the high conical, multispiral protoconch of Fraudifusinus differs from the paucispiral one of Pseudofusus (but we note that protoconch morphology is not always a reliable feature to separate genera). Fraudifusinus is reminiscent of the extant Indo-West Pacific Fusolatirus Kuroda & Habe, 1971 [type species Peristernia pilsbryi Kuroda & Habe, 1952 (= Fusolatirus coreanicus (E.A. Smith, 1879), by original designation; present-day, Western Pacific] (see Snyder & Callomon 2005 and Snyder & Bouchet 2006 for discussion). Especially species Fusolatirus coreanicus (E.A. Smith, 1879) and Fusolatirus balicasagensis ( Bozzetti, 1997) are morphologically close to Fraudifusinus , but Fusolatirus species have a more twisted siphonal canal, a more prominent fasciole and lack denticles in the outer lip at the transition to the siphonal canal.

Fraudifusinus seems to have been endemic to the Central Paratethys during the Badenian and is represented by three species, suggesting a moderate radiation there. A specimen described by Montanaro (1935: pl. 4, fig. 2) from the Tortonian of Montegibbio ( Italy) as Fusus crispoides might represent a Pseudofusus .