Cirsotrema crassicostanomalum ( Sacco, 1891 )

Harzhauser, Mathias & Landau, Bernard M., 2025, The Epitoniidae (Gastropoda, Epitonioidea) of the Miocene Central Paratethys Sea-an overwhelming diversity, Zootaxa 5630 (1), pp. 1-142 : 38-40

publication ID	https://doi.org/10.11646/zootaxa.5630.1.1
publication LSID	lsid:zoobank.org:pub:89462472-D932-4255-880F-C6EF15220A31
persistent identifier	https://treatment.plazi.org/id/03D787A4-FFC0-FFC3-FF3F-FAAEFD9D9079
treatment provided by	Plazi
scientific name	Cirsotrema crassicostanomalum ( Sacco, 1891 )
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Treatment

Cirsotrema crassicostanomalum ( Sacco, 1891)

Figs 14A–C View FIGURE 14 , 15C–D View FIGURE 15

Scalaria lamellosa Lmk.— Hauer 1837: 420 View in CoL [non Cirsotrema lamellosum ( Brocchi, 1814) ].

Scalaria lamellosa Lam.— Hörnes 1848: 22 View in CoL [non Cirsotrema lamellosum ( Brocchi, 1814) ].

Scalaria lamellosa Brocc.—Hörnes 1856: 474 View in CoL , pl. 46, fig. 7 [non Cirsotrema lamellosum ( Brocchi, 1814) ].

* C. [irsotrema] Duciei var. crassicostanomala Sacc.— Sacco 1891: 49 , pl. 2, fig. 21.

C [irsotrema]. (C [irsotrema].) crassicostatum (Desh.) — Sieber 1958: 129 [non Cirsotrema crassicostatum (Deshayes, 1850) . [ Cirsotrema duciei ] var. crassicostanomala Sacco, 1891 —Ferrero-Mortara et al. 1984: 47, pl. 5, fig. 15.

non Cirsotrema crassicostanomala Sacco, 1891 View in CoL — Harzhauser et al. 2014: 92, pl. 3, figs 1a–1b [= Cirsotrema schneideri sp.

nov.].

Type material. Lectotype (designated herein): BS.030.08.016, SL: 25.5 mm, MD: 15.7 mm, Colli Tortonesi , illustrated in Ferrero-Mortara et al. (1984: pl. 5, fig. 15). The origin of the shell described by Sacco (1891) is unclear. The collection label indicated the Late Miocene locality Tortona but Sacco (1891) doubted this provenance and suggested that the specimen is derived from a “ facies elveziana ”, which would be Burdigalian or Langhian.

Illustrated material. NHMW 1872/0030/0080, SL: 46.8 mm, MD: 21.7 mm, Baden-Sooss ( Austria), Figs 14A View FIGURE 14 1 –A View FIGURE 1 2 View FIGURE 2 , 15C View FIGURE 15 . NHMW 1866/0040/0217, SL: 44.6 mm, MD: 22.8 mm, Baden-Sooss ( Austria), illustrated in Hörnes (1856: pl. 46, fig. 7), Figs 14B View FIGURE 14 1 –B View FIGURE 1 2 View FIGURE 2 , 15D View FIGURE 15 . NHMW 2013/0300/0137, SL: 44.4 mm, MD: 18.8 mm, Baden-Sooss ( Austria), Figs 14C View FIGURE 14 1 –C View FIGURE 1 2 View FIGURE 2 .

Additional material. 10 spec., NHMW 2013 View Materials /0078/0147, Baden ( Austria) ; 11 spec., NHMW 1863 View Materials /0015/1187, Baden-Sooss ( Austria) ; 8 spec., NHMW 1869 View Materials /0001/0111 Baden-Sooss ( Austria) ; 15 spec., NHMW 2013 View Materials /0300/0135, Baden-Sooss ( Austria) ; 12 spec., NHMW 2013 View Materials /0300/0136, Baden-Sooss ( Austria) ; 9 spec., NHMW 1846 View Materials /0037/0429, Möllersdorf ( Austria) ; 2 spec., NHMW 1973 View Materials /1615/0334, Bad Vöslau ( Austria) ; 4 spec., NHMW 2010 View Materials /0004/0521, Bad Vöslau ( Austria) ; 5 spec., NHMW 199 View Materials z0178/0809, Baden ( Austria) ; 1 spec., NHMW 1863 View Materials /0015/0799, Niederleis ( Austria) .

Description. Shell large, very robust, moderately slender (apical angle ~25°). Protoconch and early teleoconch whorls unknown.Teleoconch of about ten low whorls. Early teleoconch whorls with narrow, moderately high lamellae and prominent spiral cords in interspaces forming cancellate sculpture. Later teleoconch whorls moderately convex with steep, weakly concave subsutural ramp and rounded shoulder, periphery placed just below mid-whorl. Suture moderately impressed, nearly completely obscured by lamellae. Sculpture ofclose-set, weakly prosocline, extremely broad, densely lamellose varices, not aligned axially, separated by deep, narrow interspaces (~20: ~12: 12/13). Crests of varices and interspaces with five to six prominent spiral cords. Spiral cords and interspaces with numerous delicate spiral threads causing delicately granulose crests. Last whorl attaining 45% of total height, basal angulation delimited by moderately prominent peribasal cord, flattened basal disc. Varices prominent on base with reduces spiral sculpture. Fasciole short, broad with very prominent growth lines. Aperture circular. Columella concave. Outer lip strongly thickened by varix, basal lip broad. Columellar callus forming moderately broad rim, detached from base, parietal callus delicate. Short, poorly developed abapical spout. Peristome duplex. No umbilicus.

Discussion. Cirsotrema crassicostanomala ( Sacco, 1891) is characterized by its change in sculpture from cancellate early whorls to extremely broad,lamellose varices on late teleoconch whorls. In addition, it is comparatively broad and has a relatively weakly incised suture. Hörnes (1856) confused it with Cirsotrema lamellosum ( Brocchi, 1814) , form the Pliocene of the Mediterranean Sea. Cirsotrema lamellosum has a slightly gradate outline, less convex whorls and a weakly coronate shoulder (see Pinna & Spezia 1978: pl. 58, fig. 2; Landau et al. 2006: pl. 12, figs 5–6). Later, Sieber (1958) identified the Paratethyan species as Cirsotrema crassicostatum (Deshayes, 1850) from the early Miocene of France. Although C. crassicostatum was recently discussed by Cilia (2024) and Van der Voort (2024), it is still a poorly understood species. Its understanding was distorted by numerous illustrations of specimens from the Miocene of the North Sea Basin, which in our opinion are not conspecific with C. crassicostatum . Deshayes (1850: 42, pl. 70, figs 1–3) depicted a moderately slender species with gradate spire, subcylindrical whorls with weakly convex periphery, distinct subsutural shelf and broad, orthocline, internally lamellose varices (about 16 varices on last whorl). This morphology is quite different from C. crassicostanomala and they are clearly not conspecific. Specimens shown by Cossmann (1912: pl. 3, figs 1–3) as Cirsotrema crassicostatum are slenderer, weakly coronate, have wider spaced varices and a very deep suture. A specimen from the Early Miocene of France, illustrated by Cossmann & Peyrot (1922: pl. 4, figs 97–98), as C. crassicostatum , is much slenderer and has a narrower subsutural shelf. Specimens from the Langhian of Malta described by Cilia (2024: pl. 2, figs A–N) as Cirsotrema crassicostatum (Deshayes, 1850) differ from the Paratethyan species in the slenderer outline, less convex whorls with their periphery below mid-whorl being slightly angled, and the varices are wider spaced. The Miocene Maltese specimens are quite different from Cirsotrema crassicostatum and should be treated as Cirsotrema obliquatus Cowper Reed in Baldacchino, 1939. Similarly, the specimen from the Hemmoorian of the North Sea illustrated by Janssen (1984: pl. 60, fig. 15) differs from the Paratethyan specimens in its wider spaced and narrower varices and in its deeply incised suture. Other specimens from the Miocene of the North Sea Basin, illustrated by Van der Voort (2024: fig. 1) as Cirsotrema crassicostatum differ from the Paratethyan specimens in their very broad varices and strongly convex whorls with deeply incised suture. The early teleoconch whorls of this North Sea species bear narrow axial ribs and lack the cancellate sculpture of the Paratethyan specimens. Cirsotrema taurina ( Sacco, 1891) (including its synonyms Cirsotrema pedemontanum ( Sacco, 1891) and Cirsotrema rotundicosta ( Sacco, 1891) is reminiscent of the Paratethyan species in its sculpture but differs in its incised suture and slenderer outline (see Sacco 1891: pl. 2 figs 12–15). Specimens from the Tortonian of Calabria, identified by Carone & Ardovini (2008) as C. crassicostatum might also represent C. taurina .

In summary, we recognize a partly unresolved complex of large robust Cirsotrema species in the Circum-Mediterranean region of which C. crassicostanomala is the Paratethyan representative, C. crassicostatum is found in the early Miocene of France, C. obliquatus in the Miocene Proto-Mediterranean of Malta, C. taurina the early Miocene and possibly Tortonian of Italy, and at least two species occurred in the Miocene North Sea Basin.

Paleoenvironment. Occurrences in the Baden Formation of the Vienna Basin suggest middle to outer neritic settings in up to 250 m water depth ( Kranner et al. 2021).

Distribution in Central Paratethys. Badenian (Middle Miocene): Vienna Basin: Baden, Baden-Sooss, Bad Vöslau, Möllersdorf, Niederleis ( Austria) (Hörnes 1856).

Proto-Mediterranean Sea. Tortonian (Late Miocene) of Colli Tortonesi ( Italy) or Burdigalian/Langhian of Colli Torinesi ( Italy) ( Sacco 1891).