Acrilloscala propugnaculum, Harzhauser & Landau, 2025

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 : 23-24

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-FFF3-FFFC-FF3F-FF2EFD3B97DD
treatment provided by	Plazi
scientific name	Acrilloscala propugnaculum
status	sp. nov.

Treatment

Acrilloscala propugnaculum sp. nov.

Figs 2J View FIGURE 2 , 8F View FIGURE 8 , 9A–C View FIGURE 9

Scalaria (Fuscoscala) turtonis Turt. var.— Boettger 1902: 84 [non Fuscoscala turtonis ( Turton, 1819) ].

Scala (Fuscoscala) turtonis (Turt.) var. subulata Sacco— Boettger 1906: 91 View in CoL [non Fuscoscala subulata ( Sacco, 1891) ].

Acrilloscala subuloprisca Sacco— Cossmann 1912: 188 , pl. 6, figs 18–19 [non Acrilloscala subuloprisca ( Sacco, 1891) ].

Scala (Acrilloscala) terebralis (Michelin) — Kecskeméti-Körmendy 1962: 89, pl. 10, fig. 10 [non Acrilloscala terebralis ( Michelin, 1831) ].

Acrilla (Acrilloscala) terebralis ( Michelin, 1831) — Bałuk 1975: 178, pl. 21, figs 19–20 [non Acrilloscala terebralis ( Michelin, 1831) ].

Type material. Holotype, NHMW 1864 View Materials /0001/0616, SL: 7.7 mm, MD: 2.4 mm, Grund ( Austria), Figs 9B View FIGURE 9 1 – B View FIGURE 1 2 View FIGURE 2 . Paratypes, NHMW 2024 View Materials /0279/0001, SL: 12.1 mm , MD: 4.6 mm, Grund ( Austria), Figs 8F View FIGURE 8 1 –F View FIGURE 1 2 View FIGURE 2 . NHMW 2007 View Materials /0086/0165b, SL: 9.3 mm , MD: 3.2 mm, Baden ( Austria), Figs 2J View FIGURE 2 , 9A View FIGURE 9 1 –A View FIGURE 1 2 View FIGURE 2 . NHMW 2007 View Materials /0086/0165a, SL: 9.9 mm , MD: 3.3 mm, Baden ( Austria), Figs 9C View FIGURE 9 1 –C View FIGURE 1 2 View FIGURE 2 .

Type locality. Grund ( Austria), North Alpine-Carpathian Foreland Basin .

Type stratum. Grund Formation.

Age. Middle Miocene, early Badenian (Langhian).

Etymology. Propugnaculum (Latin for a rampart; figurative for a defense), noun in apposition.

Diagnosis. Medium-sized, turreted, slender shell with moderately impressed suture, multispiral protoconch, weakly angled teleoconch whorls and widely spaced, relatively broad, low, prosocline lamellae and delicate microsculpture of spiral cords in axial interspaces.

Description. Medium-sized small, turreted, slender (apical angle ~15°). Protoconch turreted of four smooth, weakly convex whorls (fide Bałuk 1975). Teleoconch whorls high, moderately convex, with steep, weakly concave subsutural ramp, angled at shoulder, convex below, periphery placed just below mid-whorl. Suture moderately impressed, linear. Sculpture of delicate, moderately broad, weakly raised, widely spaced, slightly prosocline lamellae, vaguely aligned axially (10: 11/12: 12). Tips of lamellae weakly alate, attached to preceding whorl. Faint spiral threads in axial interspaces only visible under strong magnification. Last whorl attaining ~35% of total height, bearing few more prominent varices formed by amalgamation of lamellae, weak basal angulation without clear peribasal cord, lamellae persisting over weakly convex base, strongly rolled over. Fasciole very short, broad, with prominent growth lines. Aperture elongate ovate, columella weakly convex. Outer lip not thickened. Columellar callus forming narrow, attached rim. Parietal callus delicate. Peristome simple. No umbilicus.

Discussion. Acrilloscala subuloprisca ( Sacco, 1891) , from the Tortonian of the Proto-Mediterranean Sea, has strongly angled whorls that are more constricted below the periphery. In addition, A. subuloprisca has narrower lamellae (see Ferrero Mortara et al. 1984: pl. 6, fig. 8b). Acrilloscala terebralis ( Michelin, 1831) (= Acrilloscala degrangei De Boury in Cossmann, 1912), from the Serravallian of France, is slenderer and has slightly less angled and higher whorls (see Ivolas & Peyrot 1900: pl. 2, figs 6–8; Cossmann 1912: pl. 3, figs 17–19; Cossmann & Peyrot 1922: pl. 4, figs 114–115).

The extant Acrilloscala lamyi (de Boury, 1909) differs in its greater number of lamellae and much weaker shoulder angulation ( Bouchet & Warén 1986: figs 1219–1221) but is otherwise similar to Acrilloscala propugnaculum sp. nov. in shape and the delicate spiral sculpture. The Pliocene type species Acrilloscala geniculata ( Brocchi, 1814) is much larger (SL up to 28.9 mm, own data B.L.), higher, slenderer and has evenly convex whorls (see Bouchet & Warén 1986: figs 1222–1223).

Paleoenvironment. At the locality Grund channels formed in middle to outer neritic environments and were filled with allochthonous assemblages uniting coastal-mudflat faunas with inner neritic ones (Zuschin et al. 2005; Roetzel 2009). The occurence in the Baden Formation suggests middle to outer neritic environments.

Distribution in Central Paratethys. Badenian (Middle Miocene): Korytnica Basin: Korytnica ( Poland) ( Bałuk 1975); North-Alpine Carpathian Foreland Basin: Grund ( Austria (hoc opus); Vienna Basin: Baden ( Austria) (hoc opus); Pannonian Basin: Várpalota ( Hungary) ( Kecskeméti-Körmendy 1962); Făget Basin: CoŞteiu de Sus ( Romania) ( Cossmann 1912).

Genus Adiscoacrilla Sacco, 1890

Type species. Acrilla coppii de Boury, 1890 , original designation by Sacco (1890: 321). Pliocene, Italy.

Diagnosis. Small, moderately slender to slightly stocky conical shells with evenly convex to faintly shouldered whorls, deeply incised suture, moderately close-set to moderately wide-spaced, thin, moderately raised lamellae, not aligned axially, crests weakly rolled over or straight, adapical tips often slightly alate. Interspaces with delicate spiral cords or threads. More or less distinct basal angulation, often with weak peribasal cord and flattened basal disc bearing distinct, low lamellae or ribs. Aperture ovate with thin peristome.

Discussion. The original diagnosis by Sacco (1890: 321) is very brief and misguiding because Sacco emphasized the absence of a “real basal disc”, which is obviously incorrect. This statement, however, led Cossmann (1912: 58) to reject Adiscoacrilla and to synonymize it with Acrilla . Consequently, Adiscoacrilla herthae ( Boettger, 1906) was placed by Zilch (1934) and subsequent authors in Acrilla H. Adams, 1860 [type species Scalaria acuminata G. B. Sowerby II, 1844 ; present-day, Strait of Malacca]. However, Acrilla is very slender with delicate thread-like lamellae ( Weil et al. 1999: 206) and is not very similar to the species placed herein in Adiscoacrilla . The genus comprises Adiscoacrilla anticoppii sp. nov., A. herthae , A. laticostata ( Bałuk, 1975) and A. walaszczyki sp. nov. from the Langhian and Serravallian of the Central Paratethys Sea, A. silentiosa ( Cossmann & Peyrot, 1922) , from the Serravallian of the northeastern Atlantic, A. libassii ( Seguenza, 1876) and A. interposita ( Sacco, 1891) , from the Tortonian of the Po Basin, and A. coppii (de Boury, 1890) [= A. lacunocostata ( Sacco, 1891) , A. depressocoppi ( Sacco, 1891) ], A. opaliaeformis ( Sacco, 1891) , A. stefanii (De Boury, 1890) and A. villalvernensis ( Sacco, 1891) from the Pliocene of the Mediterranean Sea.