Granulolabium pseudoplicatum (Friedberg, 1928) Harzhauser & Guzhov & Landau, 2023

Harzhauser, Mathias, Guzhov, Aleksandr & Landau, Bernard, 2023, A revision and nomenclator of the Cainozoic mudwhelks (Mollusca: Caenogastropoda: Batillariidae, Potamididae) of the Paratethys Sea (Europe, Asia), Zootaxa 5272 (1), pp. 1-241 : 135-137

Granulolabium pseudoplicatum (Friedberg, 1928) nov. comb.

Figs 25G–I

Potamides Schaueri Hilb. var. Eichwaldi R. Hoern. i Auing. forma elongata M. Łomn. (in coll.)— Friedberg 1914: 288, pl. 17, fig. 25.

* Potamides (Pirenella) pseudoplicatus Friedb. —Friedberg 1928: 598, text-fig. 85.

Potamides pseudoplicatus Friedb. — Friedberg 1936: 477, pl. 22, figs 16–17.

Potamides pseudoplicatus Friedberg 1928 — Zelinskaya et al. 1968.

Type material. Lectotype designated herein: ZNG PAN A-I-50/714.1, SL: 20.5 mm, MD: 8.0 mm, illustrated in Friedberg (1928, text-fig. 85), Figs 25G 1 –G 2 . Paralectotypes: ZNG PAN A-I-50/714.2, SL: 19.5 mm, MD: 7.5 mm, Figs 25H 1 –H 2 . ZNG PAN A-I-50/715, SL: 29.5 mm, MD: 9.5 mm, Figs 25I 1 –I 2; all stored in the Geological Museum of the Institute of Geological Sciences , Polish Academy of Sciences, Kraków ( Poland) .

Type locality. Zhukivtsi ( Ukraine) .

Stratigraphy. Middle Miocene, Badenian.

Revised description. Shell medium sized, moderately stout to slender conical, of more than 12 teleoconch whorls; apical angle 31–38°. Protoconch and early teleoconch whorls unknown. Later teleoconch whorls with three to four, densely spaced, spiral cords of rounded beads, arranged vertically to form more or less pronounced axial ribs.Abapical cords often slightly weaker, with coalescent beads. Whorl profile subcylindrical with narrowly incised suture. Sculpture variable due to intercalations of beaded secondary spiral cords and by bifid primary cords. Last whorl large, with convex periphery, moderately constricted, with weakly convex base. Base with prominent, weakly beaded spiral cords. No varices. Aperture ovoid, moderately wide; outer lip not thickened, with four spiral rows of granules on inner aspect in many specimens; anal canal distinctly incised, delimited medially by distinct parietal swelling; siphonal canal short, moderately incised, wide, only slightly deflected to the left. Columella strongly excavated, smooth. Columellar callus forming broad rim, sharply delimited from base.

Synonyms. Potamides schaueri eichwaldi elongata Friedberg, 1914, represents a slender morph, which co-occurs with typical specimens at the type locality ( Figs 25I 1 –I 2).

Discussion. This species is very close to Granulolabium plicatum . Both species are distinguished by the usually more stocky outline and higher last whorl of G. pseudoplicatum and by its larger parietal swelling. Elongate specimens, however, are nearly indistinguishable from the Early Miocene G. plicatum . The main rationale to keep both species separate is the large stratigraphic gap between the last Burdigalian specimens of G. plicatum and the Serravallian (late Badenian) G. pseudoplicatum . In any case, the isolated occurrence in the late Badenian faunas of the Polish-Ukrainian Fore-Carpathian Basin is enigmatic and we are not aware of any Langhian (early/middle Badenian) occurrences of comparable species in the Paratethys and the Proto-Mediterranean Sea.

Central Paratethys. Badenian (Middle Miocene): Polish-Ukrainian Fore-Carpathian Basin: Zhukivtsi (Ternopil Region, Ukraine) (Friedberg 1928), Golubytsya (Lviv Region, Ukraine) ( Friedberg 1914).

The ‘ Bicinctum -Problem’

In his influential paper on Potamides and Pirenella, Lozouet (1986) synonymized Murex bicinctus Brocchi, 1816 , from the Neogene of Italy, Cerithium pictum Basterot, 1825 , from the Early Miocene of France and Cerithium mitrale Eichwald, 1830 , from the Middle Miocene of Ukraine. This approach was followed by most subsequent authors and in the more recent literature all Paratethyan and Proto-Mediterranean occurrences of this type of shell are described as Granulolabium bicinctum ( Brocchi, 1814) ( D’Amico et al. 2012; Landau et al. 2013; Filipescu et al. 2014; Harzhauser et al. 2014; Hyžný et al. 2016; Harzhauser et al. 2018b; Dominici et al. 2020).

Lozouet (1986) based his conclusions on the analysis of material from the Early Miocene of France, but he did not include Middle Miocene shells from the Paratethys and Late Miocene material from Italy. After revision of numerous specimens from the Paratethys, the Proto-Mediterranean Sea and the northeastern Atlantic, however, we doubt that this synonymization was justified and in the following we treat the pictum / mitralis group as Tiaracerithium Sacco, 1895 , distinct from bicinctum , which is placed in Tiarapirenella Sacco, 1895 . Tiaracerithium appears already during the early Burdigalian, whereas Tiarapirenella did not occur before the late Burdigalian. Both genera are distinctly different from Granulolabium Cossmann, 1889 and we do not assume a close phylogenetic relation.

Genus Tiarapirenella Sacco, 1895

Type species. Murex bicinctus Brocchi, 1814 ; by original designation ( Sacco 1895: 60). Neogene, Italy.

Original diagnosis. “ Comprende specie affini alle Pirenella , ma turrita-acute, unpo’ mitreformi, con elevato cingulo suturale granuloso, con bocca pirifome, ricordando nella forma complessiva i Tiaracerithium , tanto che pensai dapprima trattarsi di un Gruppo solo.“ ( Sacco 1895: 60) [Includes species similar to Pirenella , but turretedacute, slightly mitriform, with an elevated, granulated sutural cord, with a pyriform aperture, recalling Tiaracerithium in its overall form, so much so that at first I thought it was a single group.]

Revised description. Medium sized, slender to moderately slender pyriform with weakly gradate spire and subcylindrical spire whorls. Protoconch unknown. Early teleoconch whorls with two weakly beaded spiral cords. Later whorls with two adsutural spiral rows of prominent, widely spaced, rounded beads. Beaded mid-whorl spiral cord may be present. Sculpture highly variable, occasionally completely reduced. Last whorl subcylindrical with moderately constricted base. Aperture ovoid, not wide. Columella strongly excavated, twisted at siphonal canal. Inner lip forming broad rim. Anal canal narrowly incised. Outer lip thin, concave at mid-whorl, convex close to adapical suture and on base in lateral view. No granules inside aperture. Siphonal canal short, moderately wide, weakly deflected to the left. Very intense color pattern of reddish squares and axially elongate rectangles, often following growth lines.

Stratigraphy and paleogeography. The genus appeared during the Karpatian (late Burdigalian) of the Central Paratethys Sea and persisted there throughout the Badenian (Langhian and Serravallian). During the Langhian climatic optimum, it reached also the northeastern Atlantic. In the Proto-Mediterranean Sea it is documented from the Tortonian of the Po Basin.

Ecology. Tiarapirenella is documented from comparatively few localities, such as St. Agata ( Italy), Várpalota ( Hungary), Grund ( Austria) and Kleinebersdorf ( Austria), where it occurs in substantial numbers. This suggests a preference for peculiar environments in which the animals occurred in large populations. At Kleinebersdorf, Grund and Várpalota, Tiarapirenella bicincta is found together with Terebralia and Ptychopotamides in deposits, which contain Avicenna pollen (Harzhauser et al. 2002). Stable isotope data by Latal et al. (2004, 2006) suggest that Tiarapirenella settled brackish water environments, tolerating freshwater input. Therefore, the landward parts of mudflats and mangroves might have been the preferred habitat of Tiarapirenella .

Discussion. Tiarapirenella was established by Sacco (1895: 60) as subgenus of Potamides . Sacco (1895) treated Tiarapirenella as distinct from Granulolabium without giving a discussion on differences. Lozouet (1986) proposed an anagenetic relation between the type species of both genera, Cerithium plicatum Bruguière, 1792 and Murex bicinctus Brocchi, 1814 and consequently placed both in Granulolabium . Whilst we follow this view for Granulolabium plicatum , we reject this generic placement for M. bicinctus . Early teleoconch whorls of Granulolabium plicatum bear three prominent spiral cords of beads on conical to subcylindrical whorls, whereas Tiarapirenella has two spiral cords. Tiarapirenella lacks any granulae inside the aperture, which are frequent for Granulolabium ( Table 2). Moreover, Tiarapirenella is characterized by a comparatively wide siphonal canal and by a very intense color pattern of reddish squares, which is unknown from Granulolabium as defined herein.

The decision of Lozouet (1986) to unite Tiarapirenella bicincta and Granulolabium plicatum in a single genus might have been based on the correct observation of ‘ bicinctum -like’ morphs of Granulolabium plicatum from the Burdigalian of the Aquitaine Basin in France ( Figs 25F 1 –F 2). These specimens are dwarf shells often with a tendency to form more prominent beads on the adapical spiral cord. These specimens, however, have internal granules in the aperture and delicate secondary spiral threads as is typical for Granulolabium . Moreover, their early teleoconch sculpture is identical with that of Granulolabium plicatum ( Fig 26J). Therefore, these shells are not conspecific with Tiarapirenella bicincta and do not represent transitional morphs. Tiaracerithium Sacco, 1895 is distinguished from Tiarapirenella by the spiral sculpture of early teleoconch whorls and the dominant adapical spiral cord of beads. In addition, both genera are distinguished by the profile of the outer lip, which are prosocline below the adapical suture in Tiaracerithium but convex in Tiarapirenella . Finally, Tiarapirenella is distinguished easily from other potamidids and batillariids by its strong and characteristic color pattern of subquadratic or rectangular squares.

Species-level taxa placed in Tiarapirenella reported from the Paratethys bicinctus . Murex . Brocchi, 1814 → Tiarapirenella bicincta ( Brocchi, 1814) dionysii . Cerithium . Hilber, 1882 → Tiarapirenella tabulata (Ĥrnes, 1856) kontkiewiczi . C e rithium. Friedberg, 1914 → Tiarapirenella tabulata (Ĥrnes, 1856) moravicaeformis. Pirenella . Papp, 1952 → Tiarapirenella bicincta ( Brocchi, 1814) nodosostriatum . Cerithium . Hilber, 1879a → Tiarapirenella tabulata (Ĥrnes, 1856) palatinotiara. Pirenella . Strausz, 1955a → Tiarapirenella tabulata (Ĥrnes, 1856) pseudonympha. Pirenella . Strausz, 1955a → Tiarapirenella tabulata (Ĥrnes, 1856) sturi . Cerithium . Hilber, 1879a → Tiarapirenella tabulata (Ĥrnes, 1856) tabulata . Melanopsis . Hörnes, 1856 → Tiarapirenella tabulata (Ĥrnes, 1856) turritogracilis. Potamides . Sacco, 1895 → Tiarapirenella bicincta ( Brocchi, 1814) variabilis . Potamides . Friedberg, 1914 → Tiarapirenella tabulata (Ĥrnes, 1856)