Kalloconus letkesensis

Harzhauser, Mathias & Landau, Bernard, 2016, A revision of the Neogene Conidae and Conorbidae (Gastropoda) of the Paratethys Sea, Zootaxa 4210 (1), pp. 1-178 : 63

Kalloconus letkesensis nov. sp.

Figs 3 M, 10E1–E3, 10F1–F4, 10G1–G4, 10H1–H3

Monteiroconus tietzei ( Hoernes et Auinger, 1879) — Kovács & Vicián 2013 (partim): 79, figs 92, 94 [non Kalloconus tietzei ( Hoernes & Auinger, 1879) ].

Holotype: Figs 10 E1–E3: SL: 29.5 mm, MD: 20.6 mm, NHMW 2016/0006/0001.

Paratype: Figs 10 F1–F4: SL: 30.1 mm, MD: 21.0 mm, NHMW 2016/0006/0002.

Additional material: 1 spec. NHMW 2016/0006/0004, 3 spec. private collection Anton Breitenberger:

Figs 10 G1–G4: SL: 40.9 mm, MD: 23.3 mm; Figs 10 H1–H3: SL: 35.5 mm, MD: 23.2 mm, Fig. 3 M: SL: 37.4 mm, MD: 26.6 mm; all specimens from Letkés, Hungary.

Type stratum: fossil-rich marly sand with coral blocks and andesite boulders of the Sámsonháza Formation ( Császár 1997).

Type locality: Letkés at the western part of the Börzsöny Mts. ( Hungary); see Kovács & Vicián (2013) for a map and description.

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

Etymology: Referring to the type locality Letkés in Hungary.

Description. Moderately small to medium sized, stout shells with very low to low spire and broad conical last whorl. Early spire weakly coeloconoid with faintly concave and striate whorls; broad, weak nodules along the shoulder of 3rd–5th spire whorl resulting in undulating suture. Later spire whorls narrowly coiled, weakly convex, weakly striate; suture narrow; last spire whorl broad and flat with shallow central broad groove, striate, passing via rounded shoulder into broad conical to faintly ventricose last whorl. Position of maximum diameter in posterior quarter of last whorl. Subsutural flexure shallow, moderately curved, strongly asymmetrical. Siphonal fasciole very weak but well demarcated from short, narrow inner lip. Siphonal canal short, straight. Aperture straight, moderately narrow, slightly broadening towards siphonal canal. Delicate spiral grooves on lower third of last whorl. Very prominent colour pattern in UV light consisting of very densely spaced spirals of thin, delicate dashes covering the entire last whorl. Below the maximum diameter, slightly below mid-whorl and on the base, the dashes area arranged in three darker bands. Broad flammulae appear on spire whorls.

Shell measurements and ratios. n = 6: largest specimen: SL: 40.9 mm, MD: 26.6 mm, mean SL: 33.8 mm (σ = 4.8), mean MD: 22.3 mm (σ = 2.6), spire angle: µ = 138.5° (σ = 10.1°), last whorl angle: µ = 41.5° (σ = 1.9°), LW: µ = 1.52 (σ = 0.13), RD: µ = 0.73 (σ = 0.03), PMD: µ = 0.87 (σ = 0.11), RSH: µ = 0.10 (σ = 0.06).

Discussion. This species could be easily mistaken for Kalloconus berghausi ( Michelotti, 1847) or Kalloconus hendricksi nov. sp. from which it differs in the constantly striate spire whorls, the faintly ventricose last whorl and especially in the conspicuous spiral colour pattern, which differs completely from the large dots and blotches of K. berghausi and K. hendricksi . Therefore, some specimens in the Paratethyan literature might rather represent Kalloconus letkesensis than K. berghausi (e.g. Kojumdgieva in Kojumdgieva & Strachimirov 1960, pl. 51, fig. 3). Another morphologically similar species is Kalloconus neumayri ( Hoernes & Auinger, 1879) , which is distinguished easily by its colour pattern consisting of large rectangular blotches.

This species was mixed by Kovács & Vicián (2013) with Kalloconus tietzei ( Hoernes & Auinger, 1879) . It differs from K. tietzei in its smaller size, more slender outline, striate spire whorls, shallower subsutural flexure, broader last spire whorl, much weaker siphonal fasciole and the dense spirals of dashes, whereas K. tietzei shows much coarser and wider-spaced dashes.

Paleoenvironment. The locality Letkés comprises a mixed assemblage of partly reworked taxa ( Kovács & Vicián 2013); the frequent occurrence of corals suggests a shallow marine depositional environment.

Distribution in Paratethys. Badenian (middle Miocene): Pannonian Basin: Letkés ( Hungary).

Figures

FIGURE 10 A 1 – A 6. Kalloconus gallicus (Mayer-Eymar, 1890), Nemeşeşti (Romania), NHMW 2016 / 0036 / 0001. 10 B 1 – B 3. Kalloconus hungaricus (Hoernes & Auinger, 1879), Coşteiu de Sus (Romania), NHMW 1867 / 0029 / 0004. 10 C 1 – C 3. Kalloconus hungaricus (Hoernes & Auinger, 1879), Bad Vöslau (Austria), NHMW 1851 / 0013 / 0018. 10 D 1 – D 2. Kalloconus hungaricus (Hoernes & Auinger, 1879), Bad Vöslau, NHMW 2010 / 0004 / 1578. 10 E 1 – E 3. Kalloconus letkesensis nov. sp., Letkés (Hungary), NHMW 2016 / 0006 / 0001, holotype. 10 F 1 – F 4. Kalloconus letkesensis nov. sp., Letkés (Hungary), NHMW 2016 / 0006 / 0002, paratype. 10 G 1 – G 4. Kalloconus letkesensis nov. sp., Letkés (Hungary), private collection Anton Breitenberger. 10 H 1 – H 3. Kalloconus letkesensis nov. sp., Letkés (Hungary), private collection Anton Breitenberger.