Thericium grundense ( Sacco, 1895 )

Thericium grundense ( Sacco, 1895)

Figs 27E, 47A–D View FIGURE 47

Cerithium crenatum Brocc. View in CoL var.— Hörnes 1855: 408 (pars), pl. 42, fig. 14 [non Thericium crenatum ( Brocchi, 1814) View in CoL ].

* [ Cerithium crenatum View in CoL ] var. grundensis Sacc.— Sacco 1895: 19 .

Cerithium procrenatum Sacco var. Grundensis Sacc.— Vetters 1910: 148 .

Cerithium (Ptychocerithium) procrenatum Sacco— Sieber 1937: 493 , pl. 24, fig. E2 [non Thericium procrenatum ( Sacco, 1895) ].

Cerithium (Ptychocerithium) crenatum Brocchi var. communicata n. v. — Sieber 1937: 494, pl. 24, fig. E1 [non E3 = Thericium poetzleinsdorfense ( Sacco, 1895) ].

Cerithium cf. procrenatum (Sacco) — Zlinská & Fordinál 1992: 73, pl. 15, fig. 1 [non Thericium procrenatum ( Sacco, 1895) ].

Cerithium (Ptychocerithium) crenatum Brocchi— Schultz 1998: 54 View in CoL , pl. 22, fig. 3 [non Thericium crenatum ( Brocchi, 1814) View in CoL ].

non Cerithium procrenatum Sacco var. Grundensis Sacco— Bauer 1900: 32 , pl. 1, fig. 11 [= Terebralia sp. ]. Type material. Holotype, NHMW 1855/0045/0767, SL: 39.3 mm, MD: 13.9 mm, Grund ( Austria), illustrated in Hörnes (1855: pl. 42, fig. 14), Figs 47A View FIGURE 47 1 –A View FIGURE 1 2 View FIGURE 2 .

Illustrated material. NHMW 2023/0045/0001, SL: 42.1 mm, MD: 14.3 mm, Grund ( Austria), Figs 27E, 47B View FIGURE 47 1 – B View FIGURE 1 2 View FIGURE 2 . NHMW 2023/0045/0002, SL: 41.2 mm, MD: 13.1 mm, Grund ( Austria), Fig. 47C View FIGURE 47 . NHMW 2023/0045/0003, SL: 42.9 mm, MD: 13.3 mm, Grund ( Austria), Fig. 47D View FIGURE 47 .

Additional material. 10 spec., NHMW 2023 View Materials /0045/0004, Grund ( Austria) ; 14 spec., NHMW 1861 View Materials /0040/0073, Grund ( Austria) ; 2 spec., NHMW 2023 View Materials /0045/0005, Grund ( Austria) ; 1 spec., NHMW 1999 View Materials z0004/0032, syntype of Cerithium crenatum communicata Sieber, 1837 , Grund ( Austria) ; 1 spec., NHMW 1999 View Materials z0004/0024, Guntersdorf ( Austria) , illustrated in Sieber (1937, pl. 24, fig. E2).

Revised description. Large, slender conical shell of about 13 teleoconch whorls, attaining ~ 35–45 mm in height; apical angle 28–30°. Protoconch unknown. Early teleoconch whorls convex, rather low with prominent subsutural spiral cord and prominent axial ribs, separated by slightly wider interspaces. Two tubercular spiral cords placed mid-whorl and above abapical suture appear on axial ribs around fourth teleoconch whorl. Around sixth to seventh teleoconch whorl profile becomes faintly convex to straight sided, adapical spiral differentiates into tubercular subsutural cord delimited from other cords by deeper groove, this differentiation more marked in some specimens than others. Tubercles on all spirals low, rounded, of roughly equal strength, with one secondary intercalated in each interspace. On late whorls tubercles become weaker and blurred; primary spiral cords separated by constantly widening interspace with two secondary spirals intercalated. Last whorl moderately convex to subcylindrical, attaining ~40% of total height. Base and fasciole with numerous secondary to tertiary spiral cords. Base convex passing via distinct, concave neck into weak siphonal fasciole. Aperture elongate-ovate. Columella broadly and shallowly excavated. Columellar callus forming broad rim, sharply delimited from base. Anal canal incised, weak parietal denticle. Outer lip slightly thickened, weakly crenulated. Siphonal canal moderately short and wide, slightly deflected to the left, weakly notched.

Discussion. This species might be the ancestor of Thericium poetzleinsdorfense ( Sacco, 1895) and both might be interpreted as anagenetic lineage from the early Badenian T. grundense ( Sacco, 1895) to the late Badenian T. poetzleinsdorfense . Thericium poetzleinsdorfense is distinguished from T. grundense by the more delicate sculpture, smaller, more pointed tubercles and more prominent secondary spiral cords. The sculpture weakens during ontogeny and is rather blurred on the last whorl in T. grundense but remains prominent on the last whorl of T. poetzleinsdorfense . Thericium procrenatum ( Sacco, 1895) , from the Burdigalian of the Colli Torinesi ( Italy), is reminiscent of T. grundense . However, the Italian species differs distinctly in its mid-whorl angulation and the presence of two spiral cords intercalated between the adsutural beaded cord and the mid-whorl spiral cord. Moreover, its last whorl is higher and more conically constricted (see Sacco 1895: pl. 2, fig. 1; Ferrero Mortara et al. 1984: pl. 34, fig. 12).

Paleoenvironment. The locality Grund is represented by fossiliferous channel fills, which formed in middle to outer neritic environments, bearing allochthonous assemblages uniting coastal-mudflat faunas with inner neritic ones ( Zuschin et al. 2005; Roetzel 2009). Preservation and reddish color of the fossil shells, suggest, that Thericium grundense belonged to the allochthonous shallow water fauna and not to the autochthonous deep-water fauna.

Distribution. Known so far only from the early Badenian (Early Langhian) of the type region in the North Alpine-Carpathian Foredeep and the adjacent part of the Vienna Basin in the Central Paratethys Sea.

Central Paratethys. Badenian (Middle Miocene): North Alpine-Carpathian Foredeep: Grund, Guntersdorf, Windpassing ( Austria) ( Hörnes 1855; hoc opus); Vienna Basin: Nodendorf ( Austria) ( Vetters 1910); Danube Basin: Smolenice ( Slovakia) ( Zlinská & Fordinál 1992).