Hemiacirsa incusa, Harzhauser & Landau, 2025
|
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-FFA6-FFA0-FF3F-FF2EFF60959D |
|
treatment provided by |
Plazi |
|
scientific name |
Hemiacirsa incusa |
| status |
sp. nov. |
Hemiacirsa incusa sp. nov.
Figs 24D View FIGURE 24 , 25E–H View FIGURE 25
Type material. Holotype, NHMW 1863 View Materials /0015/0803a, SL: 6.3 mm, MD: 1.8 mm, Niederleis ( Austria), Figs 24D View FIGURE 24 , 25E View FIGURE 25 1 –E View FIGURE 1 2 View FIGURE 2 . Paratypes, NHMW 1863 View Materials /0015/0803b, SL: 7.2 mm , MD: 2.1 mm, Niederleis ( Austria), Figs 25F View FIGURE 25 1 –F View FIGURE 1 2 View FIGURE 2 . NHMW 1863 View Materials /0015/0803c, SL: 5.9 mm , MD: 1.9 mm, Niederleis ( Austria), Figs 25G View FIGURE 25 1 –G View FIGURE 1 2 View FIGURE 2 . NHMW 1863 View Materials /0015/0803d, SL: 6.5 mm , MD: 1.9 mm, Niederleis ( Austria), Fig. 25H View FIGURE 25 .
Additional paratypes. 4 spec., NHMW 1863 View Materials /0015/0803e, Niederleis ( Austria) .
Type locality. Niederleis ( Austria), Vienna Basin.
Type stratum. Baden Formation.
Age. Middle Miocene, middle Badenian (Langhian).
Etymology. After incusus, Latin for ‘hammered out’, referring to the sculpture.
Diagnosis. Small, moderately slender subulate, glossy shell with slightly cyrtoconoid outline, weakly impressed, undulating suture, weakly convex whorls, sculpture of prominent, somewhat fold-like, opisthocline axial ribs, weak to subobsolete spiral sculpture in interspaces, aperture ovate, simple.
Description. Shell small, moderately slender subulate, glossy with slightly cyrtoconoid spire (apical angle ~25°). Protoconch largely missing; last protoconch whorl convex, smooth. Teleoconch of up to eight weakly convex whorls, with periphery placed below mid-whorl. Suture weakly impressed, undulating. Sculpture of moderately prominent, weakly delimited, fold-like, opisthocline axial ribs, vaguely obliquely arranged axially, separated by wider interspaces (8/9: 8/9: 8), about one rib per whorl varicose. Spiral sculpture of subobsolete spiral cords, barely visible in interspaces. Last whorl attaining about 35% of total height, with rounded basal angulation delimited by up to three weak peribasal cords, often strongly reduced, base weakly convex, almost smooth, bearing subobsolete spiral cords. Aperture relatively small, elongate ovate. Columella weakly convex. Outer lip slightly thickened by terminal varix close to thin peristome. Columellar callus forming narrow rim, detached from base. Parietal callus delicate. Umbilicus reduced to narrow chink.
Discussion. This species could be mistaken for Hemiacirsa drevermanni (de Boury in Cossmann, 1912) but differs in its cyrtoconoid spire, subobsolete spiral sculpture and the relatively more rounded basal angulation. Hemiacirsa miocenica ( Seguenza, 1880) is much larger and differs in its prominent spiral sculpture. We are not aware of any other species from the circum-Mediterranean Miocene with comparable shape and sculpture. Hemiacirsa oscari (De Boury in Cossmann, 1912) differs in its more convex whorls.
Paleoenvironment. The Niederleis section, sediment and biota from coastal and lagoonal environments not exceeding 30 m water depth were transported by tempestites into offshore settings ( Mandic et al. 2002).
Distribution in Central Paratethys. Badenian (Middle Miocene): Vienna Basin: Niederleis ( Austria) (hoc opus).
| MD |
Museum Donaueschingen |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.