Tiarapirenella bicincta ( Brocchi, 1814 )

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 : 137-138

Tiarapirenella bicincta ( Brocchi, 1814)

Figs 27A–J, 26K

* Murex bicinctus nob. — Brocchi, 1814: 446, pl. 9, fig. 13.

? Cerithium discolor — Dujardin 1837: 288.

Cerithium articulatum Cos. — Costa 1855: 172

C [erithium]. articulatum Costa — Seguenza 1880: 155, pl. 11, figs 24–24a.

[ Potamides ] Tiarapirenella bicincta (Br.) — Sacco 1895: 60, pl. 3, fig. 52.

[ Potamides ] T [iarapirenella]. bicincta var. dertobicincta Sacc. — Sacco 1895: 60, pl. 3, fig. 52 bis.

[ Potamides ] T [iarapirenella]. bicincta var. pseudocarinata Sacc. — Sacco 1895: 60, pl. 3, fig. 53.

[ Potamides ] T [iarapirenella]. bicincta var. turritogracilis Sacc. — Sacco 1895: 60, pl. 3, fig. 54.

[ Potamides ] T [iarapirenella]. bicincta var. propinquicincta Sacc. — Sacco 1895: 61, pl. 3, fig. 55.

[ Potamides ] T [iarapirenella]. bicincta var. sexcincta Sacc. — Sacco 1895: 61, pl. 3, fig. 56.

[ Potamides ] T [iarapirenella]. bicincta ? var. pergranulina Sacc. — Sacco 1895: 61, pl. 3, fig. 57.

? Pirenella discolor Dujardin — Cossmann & Peyrot 1922: 276, pl. 6, figs 51 – 52.

Pirenella bicincta Brocchi var. turritogracilis Sacco — Sieber 1937: 482, pl. 24, figs A3, 5, 6.

? Potamides (Pirenella) discolor ( Dujardin, 1837) — Glibert 1949: 137, pl. 9, figs 14a–b.

Pirenella bicincta moravicaeformis n. ssp. — Papp 1952: 113, pl. 2, figs 27–33.

Pirenella bicincta turritogracilis (Sacco) — Papp 1952: 112, pl. 2, figs 13–19, 20–26.

Pirenella bicincta (Brocchi) 1814 —Rossi Ronchetti 1955: 125, fig. 60.

P [otamides]. bicincta turritogracilis Sacc.— Sieber 1958: 136.

Murex bicinctus Brocchi, 1814 — Pinna & Spezia 1978: 145, pl. 32, fig. 3.

Pirenella bicincta turritogracilis (Sacco) —Tejkal et al. 1969: 194, pl. 9B, figs 15–21

Granulolabium bicinctum ( Brocchi, 1814) — Harzhauser 2003: 194, pl. 1, fig. 3.

Granulolabium bicinctum ( Brocchi, 1814) — D’Amico et al. 2012: 162 (pars), pl. 1, fig. 11, pl. 2, figs 12–13, 16.

For a chresonymy including erroneous records of this species see Tiaracerithium pictum ( Basterot, 1825) .

Type material. Lectotype, No. 5244, SL: 28.0 mm, MD: 10.5 mm, illustrated in Rossi Ronchetti (1955: 125, fig. 60) and Pinna & Spezia (1978: 145, pl. 32, fig. 3) Note that Rossi Ronchetti (1955) considered this specimen to be the holotype, but it was not stated by Brocchi (1814) that only a single specimen was available. Therefore, the specimen has to be treated as lectotype according to ICZN 1999 Article 74.6; Figs 27A 1 –A 2.

Type locality. Piacenza region ( Italy) .

Stratigraphy. Neogene; most probably Tortonian.

Illustrated material. NHMW 2022/0063/0001, SL: 19.7 mm, MD: 6.6 mm, Kleinebersdorf ( Austria), Early Miocene, Karpatian, Figs 27B 1 –B 2. NHMW 2022/0063/0002, SL: 17.6 mm, MD: 6.1 mm, Kleinebersdorf ( Austria), Early Miocene, Karpatian, Figs 27C 1 –C 2. NHMW 2022/0063/0003, SL: 18.4 mm, MD: 6.7 mm, Kleinebersdorf ( Austria), Early Miocene, Karpatian, Figs 27D 1 –D 2. NHMW 2022/0063/0004, SL: 19.6 mm, MD: 6.6 mm, Kleinebersdorf ( Austria), Early Miocene, Karpatian, Figs 27E 1 –E 2. NHMW 1999z0004/0006, SL: 17.6 mm, MD: 6.1 mm, Gebmanns ( Austria), illustrated in Sieber (1937: pl. 24, fig. A5), Figs 27F 1 –F 2. MPUR7-3816, SL: 26.0 mm, SL: 10.4 mm, Cessaniti ( Italy), Tortonian, Late Miocene, Fig 27G. MPUR7-3815 (Senckenberg Museum), SL: 20.0 mm, SL: 7.8 mm, Cessaniti ( Italy), Tortonian, Late Miocene, Fig 27H. MPUR Museum of Paleontology, University of Rome, SL: 26.0 mm, SL: 8.9 mm, Cessaniti ( Italy), Tortonian, Late Miocene, Figs 27I 1 –I 2. MPUR7- 3666 (Senckenberg Museum), SL: 25.0 mm, SL: 9.1 mm, Cessaniti ( Italy), Tortonian, Late Miocene, Figs 27J 1 –J 2. NHMW 2022/0063/0005, SL: 11.6 mm, MD: 5.1 mm, Kleinebersdorf ( Austria), Early Miocene, Karpatian, Fig. 26K.

Additional material. Karpatian (Early Miocene): 1 spec. NHMW 1999z0004/0009, Niederkreuzstetten ( Austria), illustrated in Sieber (1937: pl. 24, fig. A6) as Pirenella bicincta turritogracilis Sacco, 1895 ; 1 spec. NHMW 1999z0004/0030, Gebmanns ( Austria), illustrated in Sieber (1937: pl. 24, fig. B6) as Pirenella bicincta turritogracilis Sacco, 1895 ; 47 spec., NHMW 1859/0045/0069, Niederkreuzstetten ( Austria); 48 spec., NHMW 1861/0050/0090, Niederkreuzstetten ( Austria);> 100 spec., NHMW 1859/0010/0022, Kleinebersdorf ( Austria).

Revised description. Shell slender pyriform, of about 11 teleoconch whorls, with high, weakly gradate, slender conical spire; apical angle ~35°. Protoconch unknown. Early teleoconch whorls with two broad spiral cords with rounded beads. Third weak spiral cord at abapical suture largely or fully covered by subsequent whorl. Later whorls typically with two spiral rows of widely spaced, rounded or subquadratic beads at adapical suture and at or slightly above abapical suture. Adapical spiral cord often forming weak keel. Weak spiral cord of beads occasionally appearing mid-whorl. Whorl profile subcylindrical to shallowly concave. Last whorl subcylindrical to slightly conical with slowly contracting, weakly convex base. Sculpture often weakening on last whorl. Weak secondary spiral cords may be intercalated between primaries. Periphery often faintly angulated coinciding with two weakly beaded peribasal spiral cords. Aperture elongated ovoid; outer lip thin, without inner granulae; anal canal narrowly incised; siphonal canal short, moderately wide, only slightly deflected to the left. Columella strongly excavated in adapical half, strongly twisted in abapical part. Columellar callus forming broad rim, fully adherent to base. Marked color pattern of reddish squares and rectangles on beads. Squares often elongate, prosocline on adapical beads, following growth lines. Similarly, beads at abapical suture slightly opisthocline following growth lines.

Synonyms. Cerithium articulatum Costa, 1855 was established for morphs with a color pattern of axially elongate squares ( Figs 27I–J). Based on the illustrations in Cossmann & Peyrot (1922), Cerithium discolor Dujardin, 1837 from the Langhian of France might represent a subjective junior synonym of Tiarapirenella bicincta , but we have not seen material to confirm this hypothesis. Potamides (Tiarapirenella) bicincta dertobicincta Sacco, 1895 is a slightly less slender morph, whereas P. (T.) bicincta turritogracilis Sacco, 1895 is a very slender morph. Potamides (T.) bicincta pseudocarinata Sacco, 1895 represents a morph with slightly carinate adapical spiral cord of beads. P. (T.) bicincta sexcincta Sacco, 1895 and P. (T.) bicincta pergranulina Sacco, 1995 represent stocky shells with distinct secondary spiral cords on the last whorl. All these “varieties” co-occur at Stazzano and S. Agata in Italy. Sacco (1895) also listed Cerithium undatopictum Mayer, 1878b as variety of Tiarapirenella bicincta . We have not seen the type specimen ( Mayer 1878b: 182, pl. 4, fig. 10) and preliminarily exclude this taxon from the synonymy.

Cerithium bicinctum Eichwald, 1852 is a secondary homonym of Cerithium bicinctum ( Brocchi, 1814) but is a subjective junior synonym of Tiaracerithium pictum ( Basterot, 1825) .

Discussion. This is a surprisingly rare species, and its true distribution is obscured by the numerous misidentifications of Tiaracerithium pictum in the literature.A separation of both species is based on early teleoconch sculpture (two broad spiral cords with beads in T. bicincta versus delicate spiral cords in T. pictum ), the generally more delicate and reduced sculpture of T. bicincta , its pyriform shape, its higher and less gradate spire and the wider siphonal canal of T. bicincta . Both species are readily distinguished by the prominent color pattern of T. bicincta .

Distribution. Only known from the Late Burdigalian (Karpatian) to the Langhian (early Badenian) of the Central Paratethys and the Tortonian (Late Miocene) of the Proto-Mediterranean Sea. In addition, it might have been present along the coast of the northeastern Atlantic during the Langhian (described as Cerithium discolor ).

Central Paratethys. Karpatian (Early Miocene); Korneuburg Basin: Kleinebersdorf, Gebmanns, Niederkreuzstetten ( Austria), Slup ( Czech Republic) (hoc opus). Badenian (Middle Miocene): North Alpine-Carpathian Foreland Basin: Grund ( Austria); Pannonian Basin: Várpalota ( Hungary) (hoc opus).

Proto-Mediterranean Sea. Tortonian (Late Miocene): Po Basin: Montegibbio, Stazzano, S. Agata ( Italy) ( Sacco, 1895). Pliocene occurrences from the Po Basin mentioned by Sacco (1895) will need verification.

? Northeastern Atlantic. Langhian (Middle Miocene): Aquitanian Basin: Manciet ( France); Loire Basin: Pontlevoy, Manthelan, Paulmy ( France).