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 : 136-137

Plagioconus lapugyensis ( Hoernes & Auinger, 1879)

Figs 30 D, 33D1–D3, 33E1–E3

Conus avellana Lam. —Hörnes 1851: 29 (partim), pl. 3, fig. 3d [non Conus avellana Lamarck, 1810 ; non figs 3a–c, = Conus s.l. mucronatolaevis (Sacco, 1893) .

[ Chelyconus ] [ Conus ] Lapugyensis n. f.— Hoernes 1878a: 195 (nomen nudum).

Conus (Chelyconus) Lapugyensis nov. form.— Hoernes & Auinger 1879: 42, pl. 1, fig. 9, pl. 5, fig. 8.

Type material. Syntype NHMW 1870 /0033/0006a, Lăpugiu de Sus ( Romania), illustrated in Hoernes & Auinger (1879, pl. 1, fig. 9) , syntype NHMW 1867 /0019/0004, Coşteiu de Sus ( Romania), illustrated in Hoernes & Auinger (1879, pl. 5, fig. 8) . 7 syntypes NHMW 1867 /0019/0005, Coşteiu de Sus ( Romania) ; 4 syntypes NHMW 1870 / 0033/0006, Lăpugiu de Sus ( Romania); middle Miocene, Badenian ( Langhian ).

Studied material. Syntypes.

Illustrated material. Figs 30 D, 33D1–D3: syntype, Lăpugiu de Sus ( Romania), SL: 60.6 mm, MD: 28.2 mm, NHMW 1870/0033/0006a, illustrated in Hoernes & Auinger (1879, pl. 1, fig. 9); Figs 33 E1–E3: syntype, Coşteiu de Sus ( Romania), SL: 44.6 mm, MD: 22.0 mm, NHMW 1867/0019/0005.

Revised description. Medium-sized to moderately large, not very solid, elongate pyriform shells with mammillate spire and pointed apex with weakly coeloconoid initial part. Early spire whorls carinate, coarsely beaded; suture deeply canaliculated, undulating; later spire whorls convex with deep suture; weakly striate. Subsutural flexure of medium depth, moderately curved, strongly asymmetrical. Last spire whorl slightly broader and inflated, forming a strongly convex shoulder coinciding with position of maximum diameter. Last whorl constricted mid-whorl passing into moderately narrow, long, weakly recurved canal. Distinct spiral grooves on lower half of last whorl demarcating flat to weakly convex cords. Aperture narrow; fasciole weak, slightly twisted, usually with 2–3 strongly raised growth lines from previous siphonal canal margins. Colour pattern under UV light consisting of flammulae on shoulder reaching down on upper part of last whorl; below on last whorl follow spirally arranged short dashes and speckles, arranged into discontinuous bands and into irregular axial stripes.

Shell measurements and ratios. n = 10: largest specimen: SL: 60.6 mm, MD: 28.2 mm, mean SL: 44.8 mm (σ = 8.2), mean MD: 21.4 mm (σ = 3.2), spire angle: µ = 98.2° (σ = 5.1°), last whorl angle: µ = 34.3° (σ = 1.9°), LW: µ = 2.1 (σ = 0.15), RD: µ = 0.6 (σ = 0.03), PMD: µ = 0.89 (σ = 0.03), RSH: µ = 0.17 (σ = 0.05).

Discussion. Despite some superficial similarities, this rare species differs from Leporiconus suessi ( Hoernes & Auinger, 1879) in its shorter and more dome-shaped spire, the canaliculated suture, the broad, inflated last spire whorl, the constricted base, the pyriform outline and the prominent spiral cords on the base. It can generally be distinguished from Paratethyan Leporiconus species by its strongly asymmetrical subsutural flexure.

This species was synonymized with Lautoconus pelagicus ( Brocchi, 1814) by Hall (1966) from which it is distinguished by its spire shape, the canaliculated suture and elongate pyriform outline. In addition, the colour pattern of L. pelagicus , as described by Hall (1966) and Landau et al. (2013) differs from Plagioconus lapugyensis. Conus sturi Hoernes & Auinger, 1879 and Leporiconus transsylvanicus ( Hoernes & Auinger, 1879) differ in their well defined tubercles on early spire whorls.

Paleoenvironment. Unknown; the fine grained sediment infill might indicate offshore habitats.

Distribution in Paratethys. Badenian (middle Miocene): Transylvanian Basin: Lăpugiu de Sus, Coşteiu de Sus ( Romania) ( Hoernes & Auinger 1879; Boettger 1902).

Figures

FIGURE 33 A 1 – A 3. Plagioconus puschi (Michelotti, 1847), Gainfarn (Austria), NHMW 2013 / 0479 / 1615. 33 B 1 – B 3. Plagioconus puschi (Michelotti, 1847), Gainfarn (Austria), NHMW 1860 / 0001 / 0062. 33 C 1 – C 3. Plagioconus puschi (Michelotti, 1847), Gainfarn (Austria), NHMW 1851 / 0013 / 0062. 33 D 1 – D 3. Plagioconus lapugyensis (Hoernes & Auinger, 1879), Lăpugiu de Sus (Romania), NHMW 1870 / 0033 / 0006 a, syntype. 33 E 1 – E 3. Coşteiu de Sus (Romania), NHMW 1867 / 0019 / 0005. 33 F 1 – F 3. Pseudonoduloconus gastaldii (Michelotti, 1847), Lăpugiu de Sus (Romania) SMF XII. 2246 a. 33 G 1 – G 2. Pseudonoduloconus austriacus (Hoernes & Auinger, 1879), Lăpugiu de Sus (Romania), NHMW 1875 / 0009 / 0001, syntype. 33 H 1 – H 4. Pseudonoduloconus austriacus (Hoernes & Auinger, 1879), Steinebrunn (Austria), NHMW 1866 / 0011 / 0106, syntype. 33 I 1 – I 3.. Pseudonoduloconus wagneri (Boettger, 1902), Coşteiu de Sus (Romania); SMF XII. 2204 a, holotype.