Clathrus corrugatus, Harzhauser & Landau, 2025

Clathrus corrugatus sp. nov.

Figs 15K View FIGURE 15 , 17A View FIGURE 17 1 –A View FIGURE 1 2 View FIGURE 2

Cirsotrema aff. crassicostatum ( Deshayes, 1839) —Harzhauser 2002: 93, pl. 12, fig. 6.

Type material. Holotype, NHMW 2000 View Materials z0092/0008, SL: 21.8 mm, MD: 9.9 mm, Karnabrunn ( Austria), Figs 15K View FIGURE 15 , 17A View FIGURE 17 1 –A View FIGURE 1 2 View FIGURE 2 .

Type locality. Karnabrunn ( Austria), Korneuburg Basin .

Type stratum. Korneuburg Formation

Age. Early Miocene, Karpatian (late Burdigalian).

Etymology. Corrugatus (Latin for wrinkled, corrugated).

Diagnosis. Large, robust, moderately broad, gradate, weakly coronate shell with very prominent, trigonal varices with slightly rolled over crests and seven prominent but low spiral cords giving surface corrugated appearance.

Description. Shell large, robust, moderately broad (apical angle ~30°), weakly coronate. Protoconch unknown. Early teleoconch whorls convex with, strongly raised varices, separated by slightly wider interspaces.Later teleoconch whorls gradate, nearly subcylindrical, with moderately broad subsutural shelf. Suture deeply impressed. Sculpture of moderately broad, prosocline, widely spaced, weakly trigonal, internally slightly lamellose varices, not aligned axially, separated by slightly wider interspaces (10: 12: 12). Crests of varices weakly rolled over. Interspaces with seven prominent but low, convex spiral cords separated by slightly narrower interspaces, giving surface corrugated appearance. Secondary spiral cords appear especially close to the suture. Last whorl attaining about 45% of total height, with rounded basal angulation delimited by broad, prominent peribasal cord, relatively narrow basal disc, varices weak on base. Fasciole short, broad, with very prominent growth lines. Aperture subcircular, columella concave. Outer lip not preserved. Columellar callus forming moderately broad, adherent rim, parietal callus thin, attached. No umbilicus.

Discussion. Some Cirsotrema species are reminiscent of Clathrus corrugatus sp. nov. but all differ in their lamellose varices and continuous peribasal cord. [e.g.: Cirsotrema crassicostatum (Deshayes (1850), from the Early Miocene of France, is slenderer, is more weakly coronate, and has more numerous and lamellose varices (see Cossmann 1912: pl. 3, figs 1–3). A specimen from the Early Miocene of France, illustrated by Cossmann & Peyrot (1922: pl. 4, figs 97–98), as Cirsotrema crassicostatum is much slenderer, has more numerous varices and has a narrower subsutural shelf. Cirsotrema subaspromontanum ( Sacco, 1891) , from the Tortonian of Italy, differs in its broader varices, which are overrun by spiral cords, the more superficial suture, distinctly subcylindrical whorls and markedly angled base].

Paleoenvironment. Shallow marine, lagoonal in vicinity of mangroves ( Harzhauser et al. 2002). Distribution in Central Paratethys. Karpatian (Early Miocene): Korneuburg Basin: Karnabrunn ( Austria)

(Harzhauser 2002).

Genus Claviscala de Boury, 1909

Type species. Scalaria richardi Dautzenberg & de Boury, 1897 View in CoL ; original designation by de Boury (1909a: 256). Present-day, Azores.

Diagnosis. “ Fairly large size ; narrow, slender shape; very long, subulate spire; concavo-convex, elevated whorls, separated by sutures bordered or even framed by two small cords; sculpture made up of slightly flexuous axial ribs, which do not extend from one suture to the next or even cease without reaching the sutural cord, but which nevertheless correspond from one whorl to the next, forming a slightly twisted pyramid around the axis; they are crossed by very fine, very regular spiral striae, which persist right up to the cords. Last whorl at most equal to one-fifth or one-sixth of the total height; base slightly excavated towards the periphery, where it is bordered by a projecting cord, while in the center it is slightly convex; the entire surface of the basal disc is decorated with spiral striations, even finer than those on the whorls of the spire, which are not latticed. Narrow opening, with an upwardly indented lip, where the basal cord ends.” (translated from Cossmann 1912: 92–93).

Discussion. MolluscaBase eds (2024d) currently lists twelve species under Claviscala de Boury, 1909 . A comparison of these species with the type species suggests that this genus is misinterpreted by most authors. The Atlanto-Mediterranean type species and the Miocene Paratethyan Claviscala norica Harzhauser & Landau, 2014 are characterized by weakly convex whorls with a weakly impressed suture, fold-like axial ribs terminating abapically in an adsutural spiral cord and reaching adapically close to a weaker subsutural cord. Claviscala terebraloides ( Kilburn, 1975) from the Indian Ocean, and the IWP-species Claviscala kuroharai Kuroda in Habe, 1961 agree well with the type, except for their slightly more convex whorls. In contrast, the Miocene Claviscala shimajiriensis MacNeil, 1961 and the extant C. dushaneae Brown, 2019 , C. midwayensis Habe & Kosuge, 1970 , C. nagaii Nakayama, 2000 , C. nodulosa Nakayama, 2000 , C. pellisanserina García, 2003 , C. subulae Nakayama, 2000 and C. vivienneae García, 2003 all differ from the type species in their convex whorls, comparatively more deeply incised suture and in their prominent spiral sculpture. These species should probably be excluded from Claviscala . Another potential fossil Claviscala species was described by Hutton (1885) from the Tertiary of New Zealand as Scalaria marginata . We have not seen this species but the description by Hutton (1885: 330) does not exclude placement in this genus. In the European Neogene we are not aware of any further species, except for the Paratethyan Claviscala norica Harzhauser & Landau, 2014 .