Potamides taitboutii (d’Orbigny, 1844)

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 : 75-79

Potamides taitboutii (d’Orbigny, 1844)

Figs 7J 1 –J 2, 10A–M

* Cerithium Taitboutii d’Orb., 1844 —d‘Orbigny 1844: 468, pl. 4, figs 7–9.

Cerithium disjunctoides n. sp. —Sinzow 1897: 65, pl. 3, figs 21–22.

Cerithium novorossicum n. sp. —Sinzow 1897: 66, pl. 3, figs 19–20.

Cerithium Constantiae Sabba —Stefanescu 1897: 310, pl. 8, figs 1–7.

Cerithium (Potamides) disjunctoides Sinz. — Andrussow 1906: 397.

Cerithium Istritzense nv. f.— Teisseyre 1908: 284 [nomen nudum].

Cerithium cfr. disjunctum Sow. — Văscăuţanu 1929: 111, pl. 8, fig. 14.

Cer [ithium]. (Potamides) disjunctoides Sinz. — Arkhangelsky et al. 1930: 24.

Cer [ithium]. (Potamide s) novorossicum Sinz. — Arkhangelsky et al. 1930: 24.

Cerithium novorossicum Sinz. — Davidaschvili 1931: 20, pl. 4, figs 1–2.

Cerithium disjunctoides Sinz. — Davidaschvili 1931: 19, pl. 4, figs 3–8.

Cer [ithium]. (Potamides) disjunctoides Sinz. var. plicata nov. var. — Karlov 1932: 77, pl. 1, fig. 41[non Bruguière, 1792].

Cerithium (Potamides) novorossicum Sinz. var. bigranulata nov. var. — Karlov 1932: 81.

Cerithium nefaris n. sp. — Kolesnikov 1935: 229, pl. 28, figs 35–37.

Potamides novorossicum Sinz. — Ossaulenko 1936: 88, pl. 3, figs 7–10.

Potamides disjunctoides Sinz. — Ossaulenko 1936: 87, pl. 3, figs 11–12.

Potamides novorossicum Sinz. var. planum nov. var. — Ossaulenko 1936: 88, pl. 3, figs 9–10, 17.

Potamides disjunctum Sow. — Ossaulenko 1936: 87, pl. 3, fig. 16 [non J. de C. Sowerby, 1832].

Cerithium constatiae Sabba — Simionescu & Barbu 1940: 80, pl. 1, figs 21–23

Cerithium nefaris Kol. — Simionescu & Barbu 1940: 80 (pars), pl. 1, figs 17–20 [non Kolesnikov, 1935].

Pirenella disjunctoides (Sinzow) — Wenz 1942: 66, pl. 24, figs 371–374.

Pirenella caspia (Andrussow) — Wenz 1942: 66, pl. 24, figs 375–378 [non Andrussow, 1902].

Cerithium (Thericium) disjunctum Sowerby — Tudor 1955: 99, pl. 8, fig. 64 [non J. de C. Sowerby, 1832].

Potamides novorossicus Sinzow, 1897 — Volkova 1955: 14, pl. 4a, figs 13–14.

Potamides disjunctoides (Sinzow, 1896) —Kojumdgieva 1960: 152, pl. 3, figs 13–14.

Pirenella maeotica n. sp. —Kojumdgieva 1960: 153, pl. 3, figs 15–18.

Potamides novorossicus (Sinz.) — Barg 1966: 68, pl. 2, figs 1–2.

Pirenella disjunctoides (Sinz.) — Barg 1966: 69, pl. 2, figs 3–4.

Potamides elegantus Barg sp. nov. — Barg 1966: 69, pl. 2, figs 5–6.

Potamides jagorlicus Barg sp. nov. — Barg 1966: 70, pl. 2, figs 8–11.

Potamides jagorlicus subsp. hersonica Barg subsp. nov. — Barg 1966: 70, pl. 2, figs 13–17.

Potamides disjunctoides (Sinzow, 1897) — Zelinskaya et al. 1968: 157.

Potamides novorossicum (Sinzow, 1897) — Zelinskaya et al. 1968: 159.

Potamides novorossicum planum Ossaulenko, 1937 — Zelinskaya et al. 1968: 159.

Pirenella nefaris ( Kolesnikov, 1935) — Kojumdgieva 1969: 94, pl. 33, figs 10–11.

Pirenella disjuncta disjuncta (Sowerby) — Plǎmǎdealǎ 1970: 113, pl. 6, figs 6, 8, pl. 7, figs 1–9, 12–14 [non J. de C. Sowerby, 1832].

Pirenella maeotica Kojum. — Popov 1971: 278.

Potamides novorossicum Sinz. — Okromchedlidze 1971: 64, pl. 2, figs 18–19.

Pirenella disjuncta disjuncta (Sow.) — Plǎmǎdealǎ 1973b: plate, figs 11–15 [non J. de C. Sowerby, 1832].

Pirenella disjuncta disjunctoides (Sinzow) — Roshka 1973: 196, pl. 33, figs 474 – 482.

Potamides novorossicus Sinzow, 1897 — Volkova 1974: 89, pl. 27, figs 10–11.

Cerithium disjunctoides Sinzow, 1897 — Volkova 1974: 88, pl. 27, fig. 12.

Pirenella disjuncta disjuncta (Sow.) — Iljina et al. 1976: 247, pl. 27, figs 7–8 [non J. de C. Sowerby, 1832].

Pirenella disjuncta disjunctoides (Sinz.) — Iljina et al. 1976: 91, pl. 27, figs 9–17.

Pirenella disjuncta disjuncta (Sow.) — Iljina 1979: 38, pl. 4, figs 1–2 [non J. de C. Sowerby, 1832].

Pirenella disjuncta disjunctoides (Sow.) — Iljina 1979: 38, pl. 4, figs 3–4.

P [irenella] disjuncta disjunctoides (Sinz.) — Badzoshvili 1979: 27, pl. 19, fig. 5.

P [irenella]. maeotica (Kojum.) — Badzoshvili 1979: 27, pl. 19, figs 7–8.

P [irenella]. novorossica (Sinz.)— Badzoshvili 1979: 27, pl. 19, fig. 6.

Potamides constantiae Ştefanescu — Ionesi et al. 2005: 484, pl. 10, fig. 13, pl. 17, fig. 11.

Potamides disjunctus disjunctus ( Sowerby, 1832) — Ionesi et al. 2005: 107, pl. 7, figs 1–3, pl. 9, figs 23–24, pl. 10, fig. 10, pl. 17, fig. 9 [non J. de C. Sowerby, 1832].

Potamides disjunctus conicus ( Simionescu et Barbu, 1940) — Ionesi et al. 2005: 108, pl. 7, figs 4–5, pl. 10, fig. 11, pl. 17, fig. 10 [non Blainville, 1829].

Potamides nefaris ( Kolesnikov, 1935) — Ionesi et al. 2005: 108 (pars), pl. 10, figs 14–15 [non Kolesnikov, 1935].

Pirenella disjuncta disjunctoides (Sinzov) — Popov et al. 2016: 1174, pl. 3, fig. 17.

Potamides ? sp. ( cf. disjunctus )— Lazarev et al. 2020: figs 5/9–10.

non Potamides disjunctoides Sinz. — Andrussow 1902: 53: pl. 1, fig. 4 [= Potamides caspius Andrussow, 1902 ].

non Cerithium constantiae Sabba — Simionescu & Barbu 1940: 80, pl. 1, figs 21–23 [= Theodisca biseriata ( Friedberg, 1914) ].

Type material. Lectotype designated herein: MNHN.F.R54670, SL: 20.4 mm, MD: 8.1 mm, Muséum national d’Histoire naturelle, Paris ( France), ChiȘinău ( Moldova), illustrated in d‘Orbigny , 1844, pl. 4, figs 7–9 ( Figs 10A 1 – A 2).

Type locality. ChiȘinău ( Moldova) .

Stratigraphy. Late Miocene, Sarmatian (Bessarabian).

Illustrated material. PIN 5872/8, borehole near Podil's'k ( Ukraine, Odessa Region), Sarmatian (Bessarabian), Figs 7J 1 –J 2. Nr 321/11126 (2871/339), SL: 18.8 mm, MD: 7.5 mm, Letychiv ( Ukraine), illustrated in Kolesnikov (1935: pl. 28, fig. 35). TSNIGR Museum Saint-Petersburg, lectotype (designated herein) of Cerithium nefaris Kolesnikov, 1935 , Fig. 10B. PIN 5861/2, SL: 10.6 mm, MD: 0.5 mm, Novobogdanivka ( Ukraine, Mykolaiv Region), early Maeotian, paralectotype of Cerithium novorossicum Sinzow, 1897 , Fig. 10C. PIN 5861/3, SL: 20.3 mm, MD: 0.8 mm, Novobogdanivka ( Ukraine, Mykolaiv Region), early Maeotian, syntype of Cerithium disjunctoides Sinzow, 1897 , Fig. 10D. PIN 5861/1, SL: 28.1 mm, MD: 9.9 mm, Kerch (Crimea), early Maeotian, lectotype (designated herein) of Cerithium novorossicum Sinzow, 1897 , Figs 10E 1 –E 2. PIN 5872/10, SL: 18.0 mm, MD: 6.0 mm, coast between former fishing village Nasyr and Cape Krasnyi Kut (Crimea), early Maeotian, Figs 10F 1 –F 2. PIN 5872/11, SL: 19.2 mm, MD: 7.5 mm, coast between former fishing village Nasyr and Cape Krasnyi Kut (Crimea), early Maeotian, Fig.10G. PIN 5872/12, SL: 19.0 mm, MD: 8.5 mm, Crimea, coast between former fishing village Nasyr and Cape Krasnyi Kut; early Maeotian, Fig.10H. PIN 2984/166, SL: 21.6 mm, MD: 8.9 mm, Trebujeni ( Moldova), Sarmatian (Bessarabian), Fig.10I. PIN 2984/167, SL: 19.0 mm, MD: 7.8 mm, Trebujeni ( Moldova), Sarmatian (Bessarabian), Fig.10J. PIN 5872/13, SL: 14.2 mm, MD: 6.5 mm, Tohani ( Romania, Prahova), early Maeotian, Fig. 10K. PIN 5872/3, SL: 5.2 mm, MD: 2.5 mm, borehole near Podil's'k ( Ukraine, Odessa Region), Sarmatian (Bessarabian), Fig. 10L. PIN 5872/2, SL: 8.4 mm, MD: 3.2 mm, Semenovka (Crimea), early Maeotian, Fig. 10M.

Additional material. SMF 365919, SL: 15.3 mm, MD: 5.4 mm, Valea Sălcii ( Romania), early Maeotian. SMF 365919, SL. 15.6 mm, MD: 5.2 mm, Valea Sălcii ( Romania), early Maeotian.

Revised description. Small to medium sized (20–25 mm in height), moderately slender conical shell of about ten teleoconch whorls; apical angle ~25–30°. Protoconch of one smooth, convex whorl, terminated by thickened, slightly sinuous rim from teleoconch. Early teleoconch whorls convex with incised suture and two prominent, beaded spiral cords at mid-whorl and slightly above abapical suture. Later teleoconch whorls with three prominent spiral cords with rounded to rarely spirally elongated beads. Surface of early teleoconch whorls with fine spiral striae between beads. Sculpture typically rather blunt with wide axial interspaces but highly variable including almost smooth morphs. Whorls with three, rarely two spiral cords. Adapical spiral cord close to slightly wavy suture may be reduced; mid- and adapical spirals higher, more prominent and equal is size. Beads usually axially arranged without forming continuous axial ribs.About 9–15 (typically 11–14) beads on last whorl. Whorl profile usually convex. Last whorl convex, moderately constricted with convex base, bearing 4–5 further smooth or weakly beaded spiral cords over base. Aperture subquadrate-rounded. Columella excavated, smooth. Inner lip forming rim, well demarcated from base.Anal canal indistinct. Outer lip margin sigmoidal, concave in parietal part and protruded upwards in basal part, not thickened. Siphonal canal, moderately well delimited, relatively narrow, pointing distinctly to left, forming spout-like extension abapically.

Synonyms. This species was originally described by d’Orbigny (1844) as Cerithium taitboutii . Later, Sinzow (1897) and Stefanescu (1897) described conspecific specimens again as Cerithium constantiae Stefanescu, 1897 , Cerithium disjunctoides Sinzow, 1897 and Cerithium novorossicum Sinzow, 1897 . There is no doubt that Cerithium disjunctoides Sinzow, 1897 and Cerithium constantiae Stefanescu, 1897 are two names for the same species. The paper by Sinzow (1897) appeared on pages 39 to 88 in the second part of volume 21 of the Mémoires de la Société des naturalistes de la Nouvelle-Russie. The volume was published in 1897 without more exact dates for its parts. For the paper of Stefanescu (1897) the publication date is clearly stated as July 1897 on page 1082 of volume 25 of the Bulletin de la Société Géologique de France, série 3. Thus, we are not able to clearly decide, which paper would have priority. Sinzow (1897) separated Cerithium novorossicum based on the presence of only two spiral cords, but the number of spiral cords increases during ontogeny. Iljina et al. (1976: 91) observed many intermediate specimens, and therefore considered Cerithium disjunctoides Sinzow, 1897 and Cerithium novorossicum Sinzow, 1897 as two morphs of the same species. Specimens with prominent, slightly pointed beads were described as Cerithium (Potamides) plicata by Karlov, 1932, which is a junior homonym of Cerithium plicatum Bruguière, 1792 . Cerithium nefaris Kolesnikov, 1935 is based on a morph with strongly incised suture. For specimens with reduced sculpture, Barg (1966) introduced Potamides elegantus , P. hersonica and P. jagorlicus . Similarly, Potamides planum Ossaulenko, 1936 represents a morph with reduced beads. A specimen without axial sculpture but with raised, granulated spiral cords was described by Karlov (1932) as Cerithium rubiginosum bigranulata . Comparable morphs with weak to nearly absent sculpture were already treated as Potamides disjunctoides by Iljina et al. (1976: pl. 27, figs 16–17) and Roshka (1973: pl. 33, fig. 482). Pirenella maeotica represents a morph of Potamides taitboutii with strongly reduced sculpture. Cerithium istritzense Teisseyre, 1908 is a nomen nudum referring to specimens of Potamides disjunctoides .

Discussion. The stratigraphically oldest Potamides taitboutii populations comprise morphs with reduced axial sculpture (up to full reduction). Short and small disjunctus -like shells or shells with secondary spiral threads intercalated between spiral cords may also occur in the transitional interval leading from P. disjunctus to P. taitboutii . Early Maeotian occurrences are characterized by morphs with reduced spiral and axial sculpture (e.g., P. elegantus and P. jagorlicus of Barg 1966). These shells might represent distinct eco-morphs, which have been observed by us from Romania and Russia (Ciscaucasia). Shells with reduced subsutural cord occur or even predominate in some early Maeotian populations.

Potamides taitboutii differs from P. disjunctus in its smaller size, less slender and multispiral shell, lower number of spiral cords (2–3 spiral cords versus 3–5 in P. disjunctus ), and fewer axial ribs (typically 11–14 per whorl versus typically 17–19 in P. disjunctus ). Already Sinzow (1897: 66) interpreted this species to be a descendent of Potamides disjunctus (J. de C. Sowerby, 1932) , which was followed by all subsequent authors.

Own collections (A. G.) document a rapid shift in morphospace in Potamides disjunctus with the onset of the middle Sarmatian (Bessarabian). The shells became smaller attaining not more than 25–27 mm in height compared to 35 mm in early Sarmatian populations. Dwarf specimens of Potamides disjunctus from the early Bessarabian may display dense axial sculpture, which became generally rarer during the later Bessarabian.

P. taitboutii becomes more frequent during the middle Sarmatian and prevails during the late middle Sarmatian and the late Sarmatian. These shells differ from early Maeotian shells of P. taitboutii only in their slightly larger shells and always well-developed subsutural cord. The lectotype of Potamides taitboutii was collected from the Bessarabian of Chişinău and represents such morphotype. Thus, we observe an anagenetic evolution from P. disjunctus into P. taitboutii during the early middle Sarmatian and propose to treat the middle and late Sarmatian shells as early P. taitboutii .

The early Maeotian P. galidzgensis has a geographically restricted distribution and is treated herein as offshoot of P. taitboutii . Potamides galidzgensis displays a morphological atavism because it is reminiscent of P. disjunctus due to the three prominent spiral cords and dense axial ribs, forming reticulate sculpture, but is noticeable smaller and less slender.

P. taitboitii was also mentioned as Pirenella disjuncta nefaris from a lower half of the Chersonian of Moldavian Platform and the Black Sea Lowland ( Muratov & Nevesskaja 1986: p. 104, 114).

Distribution. Potamides taitboutii occurred in the Eastern Paratethys Sea from the middle Sarmatian to the early Maeotian.

Museum Saint-Petersburg , Letychiv (Ternopil Region, Ukraine), Sarmatian (Bessarabian), lectotype of Cerithium nefaris

Kolesnikov, 1935. C. PIN 5861 /2, Novobogdanivka ( Ukraine, Mykolaiv Region) , early Maeotian, paralectotype of Cerithium novorossicum Sinzow, 1897 . D. PIN 5861 /3, Novobogdanivka ( Ukraine, Mykolaiv Region) , early Maeotian, syntype of Cerithium disjunctoides Sinzow, 1897 . E 1 –E 2. PIN 5861 /1, Kerch (Crimea) , early Maeotian, lectotype of Cerithium novorossicum Sinzow, 1897 . F 1 –F 2. PIN 5872 /10, coast between former fishing village Nasyr and Cape Krasnyi Kut (Crimea) , early Maeotian. G. PIN 5872 /11, coast between former fishing village Nasyr and Cape Krasnyi Kut (Crimea) , early Maeotian. H. PIN 5872 /12, Crimea ,

coast between former fishing village Nasyr and Cape Krasnyi Kut; early Maeotian. I. PIN 2984/166, Trebujeni ( Moldova),

Sarmatian (Bessarabian). J. PIN 2984/167, Trebujeni ( Moldova), Sarmatian (Bessarabian). K. PIN 5872/13, Tohani ( Romania,

Judeţul Prahova), early Maeotian. L. PIN 5872 /3, borehole near Podil’s’k ( Ukraine, Odessa Region), Sarmatian ( Bessarabian ) .

M. PIN 5872/2, Semenovka (Crimea), early Maeotian.

Eastern Paratethys. During the Bessarabian it is recorded only from the western part of the Eastern Paratethys. Sarmatian, Bessarabian (Late Miocene): Moldavian Platform: Letychiv (Khmel'nytskyi Region), Podil's'k (Odessa Region, Ukraine) ( Kolesnikov 1935; own data), Bohotin, Capu-Dealului, IaȘi, Nigoteşti, Nisipurile de Buzdugana, Răducăneni, Repedea, Şcheia, Ungheni at IaȘi ( Romania) ( Văscăuţanu 1929; Simionescu & Barbu 1940; Ionesi et al. 2005); Bujor, Chişinău, Coropceni ( Moldova) ( Simionescu & Barbu 1940); Dacian Basin: Alfatar, Boinitsa, Deleina, Perilovets ( Bulgaria) ( Kojumdgieva 1969). Sarmatian (Chersonian): Tsar Simeonovo ( Bulgaria) (own data).

Late Khersonian. Slănicul de Buzău ( Romania), Dacian Basin ( Lazarev et al. 2020).

Early Maeotian. Dacian Basin: Dylgodeltsi, Gomotartsi, Gromshin, Mikhailovo, Oryakhovo, Yarlovitsa, Gomotartsi, Vidin ( Bulgaria) (Kojumdgieva 1960); Coada Malului ( Wenz 1942), Ploieşti, Tohani ( Romania); Black Sea Lowland : Beryslav, Yagorlyts'kyi Kut peninsula (where was former Svobodnyi Port) (Kherson Region); Berezneguvate, Bila Krynytsya, Novobogdanivka, Novorosiiske (Mykolaiv Region); Chornomors'k (Odessa Region); Crimea: Kerch, Krasnyi Kut, Naberezhnoe, Nasyr, Semenovka, Zavetnoe, Zolotoe. Ciscaucasia: Apchas River near Kutais, Cape Popov Kamen', Tsitse River (Krasnodar Region), Aksai River near Meskety and Sogunty, Gums River between Yalkhoi-Mokkh and Akhkinchu-Borzoi (Chechnya) ( Russia) (own data); Transcaucasia: Galidzga and Gedzhiri rivers (Abkhazia) ( Badzoshvili 1979; own data); Tiblisi /Vake ( Georgia) ( Okromchedlidze 1971).