Bittium walaszczyki, Harzhauser & Guzhov & Landau, 2025

Bittium walaszczyki sp. nov.

Figs 25A–D View FIGURE 25

Bittium spina Partsch, 1842 — Nicorici 1974: 107, pl. 3, figs 24–26 [non Argyropeza spina ( Hörnes, 1855) ].

Bittium (Bittium) benoisti Cossmann & Peyrot, 1922 — Bałuk 2006: 199, pl. 8, fig. 2 [non Cossmann & Peyrot, 1922].

Type material. Holotype, BkK-G1190 , SL: 5.8 mm, MD: 1.9 mm, Korytnica ( Poland), Badenian, Middle Miocene, Figs 25A View FIGURE 25 1 –A View FIGURE 1 2 View FIGURE 2 . Paratypes. BkK-G1190 , SL: 5.8 mm, MD: 1.9 mm, Korytnica ( Poland), Figs 25B View FIGURE 25 1 –B View FIGURE 1 2 View FIGURE 2 . BkK-G1190 , SL: 5.3 mm, MD: 1.6 mm, Korytnica ( Poland), Figs 25C View FIGURE 25 1 –C View FIGURE 1 2 View FIGURE 2 . BkK-G1190 , SL: 5.0 mm, MD: 1.6 mm, Korytnica ( Poland), Fig. 25D View FIGURE 25 .

Type locality. Korytnica ( Poland), Korytnica Basin .

Type stratum. Silty clay of the so-called ‘ Pleurotoma Clays’ of the Korytnica Basin.

Age. Middle Miocene, middle Badenian (Langhian).

Etymology. In honor of Ireneusz Walaszczyk (Faculty of Geology, University of Warsaw, Poland) for his help searching for type material published by Wacław Bałuk.

Diagnosis. Small, slender pagodiform shell with very broad subsutural ramp and marked angulation. Sculpture of two prominent spiral cords crossed by narrow, widely spaced axial ribs, forming small tubercles at intersections. Weak spiral cords on subsutural ramp.

Description. Small, slender pagodiform shell of about ten, high teleoconch whorls; apical angle 25°. Protoconch conical of about 2.5 whorls (dp = ~230 μm). Teleoconch whorls developing very broad, steep subsutural ramp and marked angulation below mid-whorl. Two primary spiral cords at periphery, the upper forming the angled shoulder placed below mid-whorl, the lower close above abapical suture. About five delicate spiral cords on subsutural ramp. Weak, wide spaced axial ribs most prominent on subsutural ramp, forming horizontally elongated tubercles at intersections. Suture distinctly incised with weak spiral cord at abapical suture. Last whorl moderately constricted, attaining about 37% of total height. Base with two prominent peribasal spiral cords, three weaker cords over fasciole. Aperture ovate, moderately wide, only partly preserved. Columella weakly excavated. Columellar callus indistinct. Siphonal canal not preserved.

Discussion. Bałuk (2006) identified this specimen from the Badenian of Korytnica ( Poland) as Bittium benoisti ( Cossmann & Peyrot, 1922) , which was described from the Burdigalian of France. However, they have little in common and Bittium benoisti differs strongly in its larger size, convex whorls and prominent varices (see holotype, MNHN.F. J05916 View Materials , stored in the Muséum National d’Histoire Naturelle, Paris, France, illustrated in Cossmann & Peyrot, 1922: 287, pl. 7, figs 44–45, https://science.mnhn.fr/institution/mnhn/collection/f/item/j05916). Bittium walaszczyki sp. nov. differs from all Paratethyan Bittium species by its slender pagodiform outline and broad subsutural ramp. Argyropeza spina ( Hörnes, 1855) is slightly similar in shape but differs in its narrower subsutural ramp and more pricky tubercles.

Paleoenvironment. Unknown.

Distribution. Badenian (Langhian) of the Central Paratethys Sea.

Central Paratethys Sea. Badenian (Middle Miocene): Korytnica Basin: Korytnica ( Poland) ( Bałuk 2006). Şimleu Basin: Tusa ( Romania) ( Nicorici 1974).

A comment on Semibittium auctores, non Cossmann, 1896

Bittium turritella and Bittium tulskajense View in CoL belong to a group of Bittiinae View in CoL species in the Eurasian Miocene, which are immediately recognized by the close-set spiral sculpture, the tiny pustules in the spiral interspaces and the near absence of a siphonal canal. This group includes Rissoa turritella Eichwald, 1851 [Middle Miocene (Langhian, Serravallian) [= Bittium multiliratum Brusina, 1877 View in CoL ], Central Paratethys Sea], Semibittium duvergieri Cossmann & Peyrot, 1922 View in CoL [Middle Miocene (Serravallian), Northeastern Atlantic ( France)], Semibittium octoliratum Cossmann & Peyrot, 1922 View in CoL [Early Miocene (Burdigalian), Northeastern Atlantic ( France) and Semibittium brebioni Landau, Ceulemans & Van Dingenen, 2018 View in CoL [Late Miocene (Tortonian), Northeastern Atlantic ( France)].

Lozouet (1999) treated S. duvergieri View in CoL and S. octoliratum View in CoL as junior synonyms of Scalaria (Acirsella) perminima de Boury in Ivolas & Peyrot, 1900 and placed it in Cerithidium Monterosato, 1884 View in CoL . Cerithidium species, however, are characterized by convex, often slightly angulated whorls with comparatively coarse sculpture of beads, axial ribs and varices].

At first sight, these species differ from Bittium in the predominant spiral sculpture and strongly reduced axial sculpture. The microsculpture of spiral rows of pustules in the interspaces between the spiral cords is characteristic for these species but micropustules also occur in many Bittium species [e.g., Bittium nanum ( Mayer, 1864) in Moreno (2011, fig. 7), Bittium digitatum ( Zhizhchenko, 1934) ( Guzhov 2022: pl. 3, figs 2a–b)] and in Cerithidium Monterosato, 1884 [e.g., Cerithidium submammillatum (de Rayneval & Ponzi, 1854) in Rueda et al. (2000, fig. 4B) and have been documented herein from all Eastern Paratethyan Bittium species.

Since Cossmann & Peyrot (1922) and Glibert (1949) most of these species have been treated as Semibittium Cossmann, 1896 [type species Cerithium cancellatum Lamarck, 1804 , Middle Eocene, France]. In his brief diagnosis Cossmann (1896: 29) stated: “ The Bittium of the second group differ only from those of the first by the absence of varices and by their straighter canal ” (translated from French), without discussing other features. Semibittium cancellatum is a very slender conical species with numerous, relatively low, subcylindrical whorls. Specimens of S. cancellatum illustrated by Cossmann & Pissarro (1911: pl. 26, figs 142-12, 142-12’ display predominant spiral sculpture) but specimens with tiny, spirally and axially arranged beads occur as well (see https://science.mnhn.fr/ taxon/species/bittium/cancellatum; https://science.mnhn.fr/institution/mnhn/collection/f/item/b73463).

Houbrick (1993) suggested that the Eocene Semibittium Cossmann was congeneric with the extant Cacozeliana Strand, 1928 (type species Cerithium lacertinum Gould, 1861 , present-day, Australia). Gründel (1976), Kowalke (1998) and Bandel (2006), in contrast, treated Semibittium Cossmann as distinct genus based on its multispiral protoconch of three whorls with a cord at “ the top of the large median apertural projection of its outer lip ” ( Bandel 2006: 72). Erroneously, Houbrick (1993) stated that Semibittium would be preoccupied by Bronn (1831), Lea (1842), Tuomey (1848) and Sowerby in Dixon (1850). This, however, is incorrect and Houbrick (1993) referred to junior homonyms of Cerithium cancellatum introduced by these authors. The Miocene species differ from Semibittium in their broader, often slightly cyrtoconoid outline and higher, weakly to moderately convex whorls and are not congeneric with Semibittium Cossmann, 1896 and Cacozeliana Strand, 1928 . The presence of varices and the near absence of a siphonal canal distinguish these species additionally from Semibittium . Neostylidium Doweld, 2013 (type species Bittium eschrichtii Middendorf, 1849 , present day, Pacific) differs in its much broader flattened spiral bands.

Herein, we place the species discussed above in Bittium , because Bittium tulskajense Iljina, 1993 , from the Tarkhanian and Chokrakian of the Eastern Paratethys Sea, was shown by Guzhov (2022) to be a derived Bittium with reduced axial sculpture, related to ‘normal’ species such as Bittium digitatum ( Zhizhchenko, 1934) . In addition, juvenile shells of Bittium turritella are strikingly reminiscent of the extant Cassiella abylensis Gofas, 1987 , which is the type species of Cassiella Gofas, 1987 . This monotypic genus is characterized by its minute sizes, predominant spiral sculpture and it lacks a siphonal canal. Serge Gofas (pers comm. 23. 12. 2022), however, informed us that unpublished anatomical data indicate that Cassiella is an atypical Bittium . These two observations suggest that the entire group represents Bittium species with reduced axial sculpture, which might not even form a monophyletic group within Bittium .