Rhinoclavis eggenburgensis ( Schaffer, 1912 )

Rhinoclavis eggenburgensis ( Schaffer, 1912)

Figs 29A View FIGURE 29 1 –A View FIGURE 1 2 View FIGURE 2

* Cerithium Eggenburgense Schff.— Schaffer 1912: 151 View in CoL , pl. 51, fig. 35.

C [erithium]. (Th [ericium].) eggenburgense Schff.— Sieber 1958: 137 .

Cerithium (Thericium) eggenburgense Schaffer, 1912 — Steininger et al. 1971: 382, pl. 6, fig. 3.

Type material. Holotype, F/1142, Krahuletz Museum, SL: 34.3 mm, MD: 14.3 mm, illustrated in Schaffer (1912: pl. 51, fig. 35), Maria Dreieichen ( Austria), Early Miocene (Eggenburgian), Figs 29A View FIGURE 29 1 –A View FIGURE 1 2 View FIGURE 2 .

Revised description. Large, broad conical shell, attaining about ~ 40 mm in height; apical angle ~25°. Protoconch and early teleoconch whorls unknown. Teleoconch whorl profile straight sided with narrowly incised linear suture. Sculpture of three spiral rows of low, rounded tubercles, axially aligned without forming continuous axial ribs. One weak secondary spiral cord between each pair of beaded primary cords. Last two spire whorls becoming weakly convex. Central spiral row slightly more prominent with stronger tubercles. Tertiary spirals intercalated on last two whorls. Last whorl weakly convex with low base and numerous primary to tertiary spirals. Weak, indistinct varix on last whorl. Aperture only partly preserved. Columella excavated, smooth. Columellar callus forming broad rim, sharply delimited from base. Anal canal distinctly incised with prominent parietal denticle.

Discussion. This species is documented by a single fragmentary specimen. Nevertheless, its shape and sculpture allow a clear separation from other Paratethyan cerithiids. This species is related to the Oligocene Western Tethyan Rhinoclavis ampullosa ( Brongniart, 1823) (= Cerithium fuchsiana Sacco, 1895 ) and Rhinoclavis oligasper ( Sacco, 1895) from the Rupelian of Italy and Greece (see Fuchs 1870: 154, pl. 5, figs 4–5; Sacco 1895: 36, pl. 2, fig. 97; Ferrero Mortara et al. 1984; pl. 35, fig. 16; Harzhauser 2004, pl. 8, figs 3–4). These species are characterized by the regular sculpture of three beaded primary spiral cords on early teleoconch whorls intercalated by secondary and tertiary cords, the straight-sided whorls and the broad conical outline. Rhinoclavis ampullosa and R. oligasper differ from R. eggenburgensis ( Schaffer, 1912) mainly in their subcylindrical last whorls and higher spires. Thericium podhorcense ( Hilber, 1882) , from the Badenian of Ukraine is slightly reminiscent of Rhinoclavis eggenburgensis but has axial ribs on early teleoconch whorls, and convex spire whorls (see Friedberg 1914: pl. 16, figs 7, 12).

Paleoenvironment. Shallow sublittoral environments with sand bottoms in few meters water depth were described from the village Maria Dreieichen ( Austria) ( Mandic et al. 2004).

Distribution. Only known from the Central Paratethys.

Central Paratethys. North Alpine Foreland Basin: Eggenburgian (Early Miocene): Maria Dreieichen ( Austria) (hoc opus).

Genus Pithocerithium Sacco, 1894

Type species. Murex doliolum Brocchi, 1814 ; original designation by Sacco (1895: 28). Pliocene, Italy.

Diagnosis. “ Generally small, dolioliform, short-channeled shells with more or less granular spiral cords.” ( Sacco 1895: 28, translated from Italian).

Revised description. Small to medium sized shells often with pupoid outline or with conical spire. Sculpture of two or three spiral rows of rounded beads or tubercles placed on subsutural cord, mid-whorl and above abapical suture. Tubercles rarely pointed mid-whorl; not axially aligned on late teleoconch whorls. Prominent spiral cords and threads in interspaces between tubercles. Suture moderately incised, relatively linear. Prominent varix on last whorl. Last whorl ovate, often attaining or surpassing half of total height. Aperture ovate, wide. Anal canal distinctly incised, moderately wide. Siphonal canal very short, wide, deflected to the left. Tops of beads or tubercles with reddish color.

Discussion. Pithocerithium is characterized by its tubercular sculpture with prominent spiral cords in the interspaces between the tubercles, and by the wide aperture with short siphonal canal. These features distinguish Pithocerithium from Cerithium Bruguière, 1789 , with which it was synonymized by Houbrick (1992). Pithocerithium generally lacks a marked mid-whorl angulation with pointed tubercles, which are typical for Thericium Monterosato, 1890 . Exceptions are Sarmatian morphs of the endemic Pithocerithium rubiginosum ( Eichwald, 1830) , which developed ‘ Thericium -like’ shells with pointed tubercles and mid-whorl angulation.

Paleoenvironment. All species derive from inner neritic deposits. Pithocerithium mediolanionense nom. nov. is documented from estuarine mudflats in the vicinity of mangroves (own data M.H.). Pithocerithium rubiginosum formed huge populations on mudflats of the Sarmatian Sea.

Distribution. Represented by several species during the Early and Middle Miocene in the Northeastern Atlantic, the Proto-Mediterranean Sea, and the Central and Eastern Paratethys Sea ( Cossmann & Peyrot 1922; Sacco 1895; hoc opus). In the Proto-Mediterranean Sea, the genus is recorded also from the Late Miocene (Tortonian) ( Sacco 1895; Dominici et al. 2020) and persisted into the Pliocene ( Chirli 2006).