Cochlis paragigantica, Harzhauser & Landau & Guzhov, 2025

Cochlis paragigantica nov. sp.

Figs 15A View FIGURE 15 1 –A View FIGURE 1 4 View FIGURE 4

Natica millepunctata Lam.—Hörnes 1856: 518 View in CoL ( pars) [ non Natica millepunctata Lamarck, 1822 View in CoL = Naticarius stercusmuscarum ( Gmelin, 1791) View in CoL ].

Type material. Holotype: NHMW 1855 View Materials /0045/0785e, SL: 49.2 mm, MD: 48.2 mm, Grund ( Austria), Figs 15A View FIGURE 15 1 – A View FIGURE 1 4 View FIGURE 4 .

Type locality. Grund ( Austria), North Alpine Foreland Basin .

Type stratum. Grund Formation.

Age. Middle Miocene, early Badenian (Langhian).

Etymology. A composite of Para - from Paratethys and gigantica, Latin for gigantic, referring to the large size.

Diagnosis. Very large, globose shell with low turbiniform spire, convex spire whorls, prominent, rounded shoulder, moderately expanding last whorl, moderately wide, deep umbilicus with low, indistinct funicle and angled base.

Description. Very large, globose shell of about four teleoconch whorls; as wide as high (SL/MD = ~1.0). Spire low turbiniform of low, strongly convex whorls; apical angle 130°. Protoconch poorly preserved of ~2 smooth, convex whorls; transition to teleoconch indistinct. Suture linear, narrowly adpressed. Last teleoconch whorl with narrow, weakly convex subsutural shelf, delimited by prominent, rounded shoulder. Last whorl moderately expanding, moderately inflated, attaining ~93% of total height. Periphery moderately convex, placed mid-whorl (~49%). Growth lines distinct and weakly prosocyrt in apical view, delicate at periphery. Aperture moderately wide, D-shaped. Position of adapical tip of aperture moderately high (~84%) distinctly above mid-whorl, far below shoulder. Aperture attaining ~80% of total height. Columellar lip thick, basal lip slightly expanded into short, broad spout, outer lip thin. Columellar angle 26°. Opercular ridge in outer lip indistinct. Umbilicus moderately wide (~16%), deep, with weak growth lines. Parietal callus long (~58%), thickened with concave margin and weak anterior lobe. Funicle low, broad, poorly delimited. Basal fasciole very solid. Base weakly angled. Color pattern not preserved. Operculum unknown.

Discussion. Cochlis paragigantica nov. sp. is exceptionally large and differs from the somewhat reminiscent Cochlis neoobscura nov. sp. in its prominent shoulder, the weaker parietal callus, and much weaker anterior lobe. Cochlis unica ( Bałuk, 1995) differs in its conical spire and narrower umbilicus. Cochlis baconica ( Kókay, 1966) has an almost identical outline with a prominent, rounded shoulder but is much smaller at same growth stage and has a wider umbilicus.

Paleoenvironment. 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). Preservation and color of the fossil shells suggest that Cochlis paragigantica belonged to the allochthonous shallow water fauna and not to the autochthonous deep-water fauna.

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