Trigonostoma subsuturale ( d’Orbigny, 1852 )

Harzhauser, Mathias & Landau, Bernard, 2012, A revision of the Neogene Cancellariid Gastropods of the Paratethys Sea 3472, Zootaxa 3472, pp. 1-71 : 58-60

Trigonostoma subsuturale ( d’Orbigny, 1852)

Figs 3Y, 11C 1–C 3, 11D 1–D 3

Cancellaria suturalis Grateloup, 1832: 343 , nr. 374 [non Cancellaria suturalis G.B. Sowerby I, 1822 ].

Cancellaria acuminata Bellardi, 1841: 38 , pl. 4, figs 15–16 [non Cancellaria acuminata G.B. Sowerby I, 1832 ].

Cancellaria suturalis Grat. (non Sow.)— Grateloup 1846: pl. 25, figs 11–12 [non Cancellaria suturalis G.B. Sowerby I, 1822 ]. Cancellaria subsuturalis d’Orbigny, 1852: 10 , nr. 161.

Cancellaria subacuminata d’Orbigny, 1852: 56 , nr. 951.

Cancellaria canaliculata Hörnes, 1854: 324 , pl. 35, figs. 9–10.

Cancellaria canaliculata Hornes et Partsch — Crosse 1863: 247.

Cancellaria gainfarnensis n. f.— Handmann 1882: 262.

Cancellaria (b. Trigonostoma ) canaliculata M. Hoern. — Hoernes & Auinger 1890: 275.

Cancellaria (Trigonostoma) subacuminatum (d’Orb.) — Sacco 1894: 15, pl. 1, fig. 42.

Trigonostoma subsuturale d’Orbigny (emend.)— Peyrot 1928: 242, nr. 1140, pl. 13, figs 36–37.

Cancellaria (Trigonostoma) subacuminata d’Orb. — Sieber 1936: 81.

Trigonostoma canaliculata Hoernes — Mongin 1952: 94.

Trigonostoma (Trigonostoma) subacuminatum (Orb.) — Sieber 1956: 245

Trigonostoma subacuminatum (d’Orbigny) — Ferrero Mortara et al. 1984: 388, pl. 29, figs 9a–b.

Trigonostoma (Trigonostoma) subacuminatum (d’Orbigny) — Schultz 1998: 70, pl. 28, fig. 14.

? Genus subsuturale ( d’Orbigny, 1852) — Cahuzac et al. 2004: 230, figs 6 O–R.

non Trigonostoma (Trigonostoma) subacuminatum ( d’Orbigny, 1852) — Davoli 1982: 35, pl. 3, figs 6a–c [=?].

Type material. lectotype 65-2-98 designated by Cahuzac et al. (2004), Université de Bordeaux-1 ( France); Saint- Jean-de-Marsacq ou Saubrigues ( France), Burdigalian or Langhian (Early or Middle Miocene) .

Studied material. 17 spec. Grund ( Austria) NHMW 2009 z0098/0020, NHMW A894 , NHMW A889 , NHMW 1852 / 0012/0028, NHMW 1855 /0045/0740; 1 spec. Niederleis ( Austria) NHMW 1863 /0015/0703; 7 spec. Baden ( Austria) NHMW A373 ; 2 spec. Baden–Sooss ( Austria) NHMW 2011 /0357/0001; 2 spec. Möllersdorf ( Austria) NHMW 1863 /0015/1206.

Illustrated material. Fig. 3Y: Baden–Sooss ( Austria), height: 16.9 mm, width: 10.5 mm, NHMW 1869/0001/ 0990. Figs 11C 1–C 3: specimen illustrated in Hörnes (1854, pl. 35, figs 9a–c), Grund ( Austria), height: 44.5 mm, width: 32 mm, NHMW 2009z0098/0020. Figs 11D 1–D 3: Baden–Sooss ( Austria), height: 60.6 mm, width: 42 mm, NHMW 2011/0357/0001.

The second specimen illustrated in Hörnes (1854, pl. 35) as fig. 10 cannot be clearly identified and it might be an idealised drawing of a second, slightly worn specimens from Grund.

Description: This is one of the largest cancellariids in the Paratethys Sea, attaining a total height of up to 60 mm. The high conical shell consists of up to six strongly convex teleoconch whorls. The protoconch is multispiral dome-shaped, consisting of three whorls with a small nucleus. The early teleoconch bears 4 to 6 spiral cords and weaker axial ribs. A weak secondary spiral sculpture appears already on the first teleoconch whorl. It consists of several secondary spiral threads, which are intercalated in the interpaces, joined by threads of tertiary strength from the second teleoconch whorl onwards. About 12 moderately prominent primary cords appear on the last whorl. All spirals have a somewhat scaly microsculpture at the intersections with the delicate growth lines. Blunt, wide spaced, prosocline axial ribs predominate, and are accentuated by slight thickenings of the primary spiral cords where they overrun the ribs. The most characteristic features are the deep and canaliculated suture and the deep and wide umbilicus, which shows the bases of the preceding whorls. Two strong columellar folds may be accompanied by an insignificant accessory fold next to the upper fold. The ovoid aperture has a weak posterior angulation, a shallow siphonal canal and a wide, slightly flared outer lip. Some faint lirae appear in the lower part of the outer lip.

Discussion. Already Hörnes (1854) recognised that the Paratethyan shells are conspecific with those described by Grateloup (1832, 1846) from France and proposed Cancellaria canaliculata as replacement name for the preoccupied suturalis . Unfortunately, he was not aware that d’Orbigny (1852) had already proposed Cancellaria subsuturalis as replacement name for the very same taxon. Hörnes (1854) was also the first to list the Italian Cancellaria acuminata Bellardi with question mark in the synonymy of Cancellaria canaliculata . Crosse (1863) considered all these taxa, including the two replacement names of d’Orbigny (1852), to represent a single species and selected Cancellaria canaliculata Hörnes as valid name. This first revision, however, is invalid according to the modern rules of the ICZN as Hörnes’s name is a junior synonym in any case. Later authors, such as Sacco (1894) and Davoli (1982), were not fully convinced of the identity of the French and Italian shells and Peyrot (1928) even refuted it. The holotypes of Cancellaria subsuturalis d’Orbigny1852 and Cancellaria subacuminata d’Orbigny, 1852 have now been re-illustrated in Cahuzac et al. (2004) and Ferrero– Mortara et al. (1984), verifying that they represent a single species with some variability in spire height and apical angle, ranging from 55° to 60°. Therefore, we choose Trigonostoma subsuturale ( d’Orbigny, 1852) as valid name for this species, respecting the clear reference to Grateloup’s species by Hörnes (1854).

Handmann (1882) described Cancellaria gainfarnensis as new species from Gainfarn in the Vienna Basin. He states the similarity with Cancellaria canaliculata and distinguishes his species based on the presence of a third columellar fold. As this fold, although very weak, may occur in typical Trigonostoma canaliculata as well and because this rare species is unique in its morphology, we consider C. gainfarnensis a synonym. The Late Miocene shells identified by Davoli (1982) as Trigonostoma subacuminata represent a different, yet unnamed, species. It differs clearly in its crowded axial ribs, the coalescing spire and the narrower suture.

Distribution. This species seems to be restricted to deeper water deposits. It is known so far only by two specimens from the Burdigalian of Italy and southern France, another singleton from the Burdigalian or Langhian of northern France and few shells from the early Middle Miocene of Austria. It seems to be absent in late Badenian assemblages.

Paratethys —Badenian: North Alpine Foreland Basin ( Austria: Grund); Vienna Basin ( Austria: Niederleis, Baden–Sooss, Baden, Möllersdorf, Gainfarn); Eisenstadt–Sopron Basin ( Austria: Forchtenau). North East Atlantic —Burdigalian or Langhian: Aquitaine Basin ( France: Saint–Jean–de–Marsacq ou Saubrigues). Proto –Mediterranean Sea —Burdigalian: Colli Torinesi: ( Italy; exact locality unknown), Rhône Basin (Provence, France).