Plagioconus

Harzhauser, Mathias & Landau, Bernard, 2016, A revision of the Neogene Conidae and Conorbidae (Gastropoda) of the Paratethys Sea, Zootaxa 4210 (1), pp. 1-178 : 131-132

Plagioconus bellissimus nov. sp.

Figs 30 C, 31C1–C3, 31D1–D2, 31E1–E2, 31F1–F3

Conus (Chelyconus) sp.— Caze et al. 2010: 35, fig. 5/M1-M2.

Holotype: Figs 31 C1–C3: SL: 70.8, MD: 27.3 mm, NHMW 1874 /0025/0002a, Lăpugiu de Sus ( Romania).

Paratype: Figs 31 D1–D2: SL: 74.4, MD: 27.9 mm, NHMW 1874 /0025/0002b, Lăpugiu de Sus ( Romania).

Paratype: Figs 31 E1–E2: SL: 66.9, MD: 25.0 mm, NHMW 1890 /0001/0012a, Lăpugiu de Sus ( Romania).

Paratype: Fig. 30 C: SL: 66.9, MD: 24.7 mm, NHMW 1890 /0001/0012b, Lăpugiu de Sus ( Romania).

Fig. Figs 31 F1–F3: SL: 58.7, MD: 24.4 mm, Letkés (Hungary), private collection Anton Breitenberger (Bad Vöslau, Austria).

Additional material: 2 spec. NHMW 1874/0025/0002; 2 spec. NHMW 1890/0001/0012; 1 spec., NHMW 1973 /1615/0069; all Lăpugiu de Sus ( Romania) .

Type stratum: Badenian marly-clayey deposits with thin interlayers of sand and corallinacean limestones.

Type locality: Lăpugiu de Sus ( Romania).

Age: Middle Miocene, early Badenian (= Langhian).

Etymology: Referring to the aesthetic appearance of the species, which was overlooked so far in the collections.

Description. Moderately large, very elongate shells; spire medium-high conical, somewhat variable in height; early spire pointed, angulated just above suture; suture canaliculated. Later spire whorls feebly convex, glossy with faint spiral threads, not striate; suture deeply impressed. Subsutural flexure deep, moderately curved, strongly asymmetrical. Early spire whorls coarsely tuberculate at suture; tubercles usually covered by subsequent whorl. Last whorl convex, with rounded, sometimes bulgy shoulder coinciding with position of maximum diameter. Last whorl very elongate, conical, constricted at base. Siphonal canal very long, narrow, twisted, slightly reflected. Siphonal fasciole distinctly swollen, marked by densely spaced and prominent growth lines. Aperture narrow with subparallel margins, only weakly widening anteriorly. Wavy spiral grooves on base and lower quarter of last whorl may be developed. Colour pattern under UV light consisting of dense flammulae on spire and shoulder; last whorl with irregular pattern of densely spaced spirally arranged and amalgamating blotches, partly with vague axial arrangement. Two light (fluorescing) bands in the middle and lower third of the last whorl.

Shell measurements and ratios. n = 8: largest specimen: SL: 74.4 mm, MD: 27.9 mm, mean SL: 68.1 mm (σ = 4.4), mean MD: 25.2 mm (σ = 2.2), spire angle: µ = 86 ° (σ = 8.23), last whorl angle: µ = 24.3° (σ = 0.9°), LW: µ = 2.7 (σ = 0.07), RD: µ = 0.44 (σ = 0.01), PMD: µ = 0.95 (σ = 0.02), RSH: µ = 0.16 (σ = 0.03).

Discussion. This species was identified as Conus puschi in NHMW-collection lots and may also be mixed with Plagioconus puschi ( Michelotti, 1847) in other museum collections. Both species, however, are readily distinguished by the higher spire, the broader and shorter siphonal canal and the less constricted base of P. puschi , which is also larger. In addition, P. puschi seems to have preferred shallow water environments, whereas P. bellissimus might rather represent an offshore species. Subadult specimens of Plagioconus extensus (Hörnes, 1851) are reminiscent of P. bellissimus due to the elongate shape and long siphonal canal but are distinguished by the sutural concavity and the prominent spiral cords. Plagioconus lapugyensis ( Hoernes & Auinger, 1879) differs in its striate spire whorls, the less elongate last whorl, the broader shoulder and the shorter siphonal canal.

Paleoenvironment. All specimens from Lăpugiu de Sus are filled with clay, probably suggesting offshore environments as preferred habitat.

Distribution in Paratethys. Badenian (middle Miocene): Transylvanian Basin: Lăpugiu de Sus ( Romania); Pannonian Basin: Letkés (own data).

Figures

FIGURE 31 A 1 – A 3. Plagioconus austriaconoe (Sacco, 1893), Baden-Sooß (Austria), NHMW 2013 / 0300 / 0526. 31 B 1 – B 3. Plagioconus austriaconoe (Sacco, 1893), Lăpugiu de Sus (Romania), NHMW 1868 / 0001 / 0382. 31 C 1 – C 3. Plagioconus bellissimus nov. sp., Lăpugiu de Sus (Romania), NHMW 1874 / 0025 / 0002 a, holotype. 31 D 1 – D 2. Plagioconus bellissimus nov. sp., Lăpugiu de Sus (Romania), NHMW 1874 / 0025 / 0002 b, paratype. 31 E 1 – E 2. Plagioconus bellissimus nov. sp., Lăpugiu de Sus (Romania), NHMW 1890 / 0001 / 0012 a, paratype. 31 F 1 – F 3. Plagioconus bellissimus nov. sp., Letkés (Hungary), private collection Anton Breitenberger. 31 G 1 – G 5. Plagioconus breitenbergeri nov. sp., Letkés (Hungary), NHMW 2016 / 0041 / 0001, holotype. 31 H 1 – H 2. Plagioconus breitenbergeri nov. sp., Letkés (Hungary), NHMW 2016 / 0041 / 0002, paratype.