Clathroscala xeniae ( Boettger, 1906 )

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 : 52-54

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-FFD6-FFD1-FF3F-FE47FDA99549
treatment provided by	Plazi
scientific name	Clathroscala xeniae ( Boettger, 1906 )
status

Treatment

Clathroscala xeniae ( Boettger, 1906)

Fig 20A View FIGURE 20 , 21A View FIGURE 21

* Scala (Acrilla) xeniae n. sp. — Boettger 1906: 93.

Clathroscala xeniae (Boettger) — Cossmann 1912: 71, pl. 5, figs 16–17.

Scala (Clathroscala) xeniae (Boettger) — Zilch 1934: 230, pl. 10, fig. 80.

Clathroscala (Clathroscala) xeniae Boettger— Korobkov 1955 : pl. 15, figs 30–31.

Scala (Clathroscala) xeniae (Boettger) — Csepreghy-Meznerics 1969a: 22, pl. 4, fig. 2.

non Scala (Clathroscala) xeniae (Boettger) — Csepreghy-Meznerics 1969b: 75, pl. 1, fig. 24.

Type material. Lectotype (designated by Zilch 1934: 230), SMF 380171_12-1450a ( XII 1450 a), SL: 9.5 mm, MD: 3.5 mm, CoŞteiu de Sus ( Romania), illustrated in Zilch (1934: pl. 10, fig. 80), Fig 20A View FIGURE 20 , 21A View FIGURE 21 .

Revised description. Small, moderately slender conical shell of at least nine teleoconch whorls (apical angle 22°). Protoconch and first teleoconch whorls unknown. Teleoconch whorls convex with indistinct, weakly concave subsutural ramp, evenly rounded periphery placed just above mid-whorl, separated by deeply impressed suture. Sculpture on early teleoconch whorls of very weak, close-set axial ribs (~26: ~24: ~24). No spiral sculpture. Later whorls with slightly wider spaced, low, convex axial ribs, separated by wider interspaces, with five slightly weaker spiral cords, forming regularly cancellate pattern. Delicate spiral threads and growth lines in interspaces forming finely punctate surface. About one prominent varix per whorl. Last whorl about 35% of total height, weak basal angulation delimited by narrow peribasal cord, axial ribs terminate at peribasal cord, base flattish bearing weak spiral cords. Aperture ovate, columella weakly concave. Columellar callus forming moderately broad rim, weakly detached from base. Parietal callus delicate. Peristome duplex with thin inner layer; outer lip thickened by varix. Umbilicus reduced to narrow chink.

Discussion. Clathroscala cancellata ( Brocchi, 1814) , from the Pliocene of the Mediterranean Sea, is much larger (SL: 30 mm) and has more spiral cords (see Pinna & Spezia 1978: pl. 60, fig. 1; Landau et al. 2006: pl. 13, figs 3–4; Chirli 2009: pl. 18, figs 2–7). Clathroscala woodi (Deshayes, 1864) , from the Pliocene of the North Sea, is more delicate and more elongate (see Harmer 1920: pl. 68, fig. 9). The Paratethyan species is very similar to the apical fragment from the Tortonian of France figured by Landau et al. (2023: pl. 11, fig. 2) as C. cancellata . The French specimen has one more spiral cord and a slightly wider apical angle. Clathroscala bureaui de Boury in Cossmann, 1912 has a much narrower apical angle and differs in its taller and turreted shape, its cords are narrower and alternate in strength, and the basal sculpture is more pronounced.

Paleoenvironment. Unknown.

Distribution in Central Paratethys. Badenian (Middle Miocene): Bükk Mountains: Borsodbóta ( Hungary) ( Csepreghy-Meznerics 1969a, b); Făget Basin: CoŞteiu de Sus ( Romania) ( Boettger, 1906).

Genus Clathrus Agassiz, 1837

Type species. Scalaria acuta J. Sowerby, 1812 View in CoL , subsequent designation by Brown & Neville (2015: 21). Eocene, British Isles

Diagnosis. Medium-sized, moderately stocky conical, gradate, often coronate, with weakly convex to subcylindrical whorls, moderately wide, weakly concave subsutural shelf. Suture deeply impressed. Moderately close-set, prominent, prosocline robust, strongly raised lamellae with rolled over crests. Interspaces with broad, low, convex spiral cords. Lamellae not aligned axially, disconnected along suture. Last whorl with sub-angled base without continuous peribasal cord, lamellae prominent on base, strongly rolled over. Short, broad fasciole with prominent growth lines. Aperture subcircular, columellar callus forming broad rim detached from base, parietal callus weak, peristome thickened, duplex.

Discussion. Clathrus was originally introduced by Oken (1815: 255) but his work was placed on the Official Index by Opinion 417 ( ICZN 1956). Later, the name was made available by Agassiz (1837: 35). The complex nomenclatorial history was reviewed by Brown & Neville (2015: 21), who clarified the situation by the subsequent designation of Scalaria acuta J. Sowerby, 1812 from the Late Eocene of the British Isles as type species [for illustrations see Sowerby (1812: pl. 16, lower two figs), Duerr 2004: fig. 9 and Savazzi & Saski (2004: fig 11A–B, H)].

Sacco (1891) used Clathrus for several Miocene species from Italy and Cossmann (1912: 36) gave a first detailed diagnosis for Clathrus but this was based on an incorrect type species [ Scalaria communis Lamarck, 1822 , = Scala clathrus ( Linnaeus, 1758) ]. Therefore, Clathrus sensu Cossmann 1912 is an objective synonym of Scala Mörch, 1852 . This erroneous concept was also adopted by Weil et al. (1999). Therefore, the understanding of Clathrus varied greatly in the literature and no diagnosis was available so far for Clathrus sensu Brown & Neville (2015) .

Duerr (2004) placed Scalaria acuta J. Sowerby, 1812 in Cirsotrema , which would made Cirsotrema Mörch, 1852 a subjective junior synonym of Clathrus Agassiz, 1837 . Indeed, Clathrus as understood herein comprises a group of extant species, which are currently placed in Cirsotrema or Boreoscala Kobelt, 1902 by most authors (e.g., Boreoscala ponderosa Garcia, 2003 , Elegantiscala fimbriatula Masahito, Kuroda & Habe in Kuroda, Habe & Oyama, 1971, Epitonium (Boreoscala) blainei Clench & R. D. Turner, 1953 ), Scalaria latecostata Strebel, 1905 , Scalaria zelebori Dunker in Dunker & Zelebor, 1866). However, these species differ from Cirsotrema in their simple, non-lamellose lamellae/varices and their lamellae do not fuse laterally as seen in many Cirsotrema species. The lamellae of Clathrus are also not fused across the suture as in Boreoscala and several Cirsotrema species. Therefore, we consider Clathrus a valid genus with the type species Scalaria acuta J. Sowerby, 1812 , and not a synonym of Scala Mörch, 1852 with the type species Turbo clathrus Linnaeus, 1758 nor Cirsotrema , type species Scalaria varicosa Lamarck, 1822 .

SMF	Forschungsinstitut und Natur-Museum Senckenberg
MD	Museum Donaueschingen

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Taxonomy

Kingdom	Animalia
Phylum	Mollusca
Class	Gastropoda
Family	Epitoniidae
Genus	Clathroscala