Hemicerithium olgae ( Boettger, 1902 )

Hemicerithium olgae ( Boettger, 1902)

Figs 68A–C View FIGURE 68

* Cerithium (Conocerithium) olgae n. sp. — Boettger 1902: 117.

Cerithium (Conocerithium) olgae Boettger— Zilch 1934: 221 , pl. 8, fig. 31.

non Conocerithium (Conocerithium) olgae (Boettger, 1901) — Atanacković 1985: 109, pl. 26, figs 8–9 [= Hemicerithium evae

( Boettger, 1902)].

Type material. Holotype XII 2425 a, SL: 9.9 mm, MD: 4.2 mm, Senckenberg Forschungsinstitut und Naturmuseum Frankfurt am Main ( Germany), designated by Zilch (1934: 221, pl. 8, fig. 31), Figs 68A View FIGURE 68 1 –A View FIGURE 1 2 View FIGURE 2 . Coşteiu de Sus ( Romania), Middle Miocene, early/middle Badenian.

Illustrated material. NHMW 2023/0027/0005, SL: 3.8 mm, MD: 1.9 mm, Baden ( Austria), Figs 68B View FIGURE 68 1 –B View FIGURE 1 2 View FIGURE 2 . NHMW 2023/0043/0006, SL: 4.3 mm, MD: 2.2 mm, Coşteiu de Sus ( Romania), Fig. 68C View FIGURE 68 .

Additional material. 2 spec., NHMW 2023 View Materials /0027/0006, Baden ( Austria) ; 63 spec., NHMW 2023 View Materials /0043/0007, Coşteiu de Sus ( Romania) .

Revised description. Small, pagodiform shell of up to nine conical whorls, attaining ~ 4–10 mm in height; apical angle ~35°. Protoconch unknown. Early teleoconch whorls weakly convex with widely spaced, drop-shaped axial riblets, angulated at periphery placed close above abapical suture. Later teleoconch whorls with very broad, concave sutural ramp and prominent rounded angulation placed just above abapical suture. Angulation coinciding with prominent tubercles, separated by interspaces of about equal width (7–8 tubercles on last whorl). Spiral sculpture of faint spiral threads. Suture superficial. Last whorl with rounded angulation placed below mid-whorl, attaining ~45% of total height. Base conical, strongly constricted, not delimited by cord. Spiral threads slightly more prominent on base. Aperture moderately wide, ovate. Columella almost straight. Columellar callus forming narrow rim, poorly delimited. Siphonal fasciole weak, indistinct. Anal canal indistinct. Outer lip not preserved. Siphonal canal incised, short, slightly bent to the left.

Discussion. Hemicerithium olgae ( Boettger, 1902) is characterized by its pagodiform outline and differs clearly from its congeners H. banaticum ( Boettger, 1902) and H. evae ( Boettger, 1902) , which have broader shells and more convex whorls. Hemicerithium kovacsi sp. nov. differs in its less pagodiform outline and the prominent spiral sculpture. Hemicerithium pagodum Hoerle, 1972 , from the Burdigalian of the Chipola Formation in Florida ( USA), has a similar outline but differs in its even more slender shell, the somewhat pointed tubercles and the presence of a peribasal cord (see Hoerle 1972: pl. 2, fig. 5).

Paleoenvironment. The occurrences in the Baden Formation (Baden) suggest middle to outer neritic environments with up to 210 m water depth ( Kranner et al. 2021).

Distribution. Only known from the Badenian (Langhian) of the Central Paratethys Sea.

Central Paratethys. Badenian (Middle Miocene): Vienna Basin: Baden ( Austria) (hoc opus); Făget Basin: Coşteiu de Sus ( Romania) ( Zilch 1934).