Cirsotrema microperforata, Harzhauser & Landau, 2025
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publication ID |
https://doi.org/10.11646/zootaxa.5630.1.1 |
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publication LSID |
lsid:zoobank.org:pub:89462472-D932-4255-880F-C6EF15220A31 |
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persistent identifier |
https://treatment.plazi.org/id/03D787A4-FFCB-FFCA-FF3F-FF2EFF6093B1 |
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treatment provided by |
Plazi |
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scientific name |
Cirsotrema microperforata |
| status |
sp. nov. |
Cirsotrema microperforata sp. nov.
Figs 15I View FIGURE 15 , 18A View FIGURE 18 1 –A View FIGURE 1 2 View FIGURE 2
Type material. Holotype, NHMW 1863 View Materials /0015/0803, SL: 12.5 mm, MD: 5.7 mm, Niederleis ( Austria), Figs 15I View FIGURE 15 , 18A View FIGURE 18 1 –A View FIGURE 1 2 View FIGURE 2
Type locality. Niederleis ( Austria), Vienna Basin .
Type stratum. Baden Formation.
Age. Middle Miocene, middle Badenian (Langhian).
Etymology. Referring to the microperforate appearance of the crests of the varices.
Diagnosis. Medium-sized, robust, moderately slender, moderately gradate with faintly coronate last whorls, numerous broad, uniform, close-set varices with microperforated crests, narrower interspaced with numerous spiral threads, sharp basal angulation.
Description. Shell medium-sized, robust, moderately slender (apical angle ~30°), later whorls faintly coronate. Protoconch and first teleoconch whorls unknown. Teleoconch of about ten whorls. Early teleoconch whorls with narrow, moderately high varices and prominent spiral cords in interspaces, resulting in cancellate pattern. Later teleoconch whorls with broad, shallow, weakly concave subsutural ramp and weakly angled shoulder, subcylindrical below, with periphery placed above mid-whorl. Suture deeply impressed, largely covered by varices. Sculpture of numerous, uniform, densely spaced, broad, weakly prosocline varices, not aligned axially, separated by deep, narrower interspaces (~20: ~25: 28). Crests of varices with fine foliaceous crisscross pattern, resulting in microperforate surface appearance. Varices weakly coronate along shoulder, slightly concave on subsutural ramp. Interspaces with numerous spiral threads. Last whorl attaining 43% of total height, with marked basal angulation delimited by very prominent peribasal cord, basal disc slightly concave, varices prominent on base, spiral sculpture reduced. 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. Peristome duplex. No umbilicus.
Discussion. This species is unique within the Paratethyan Epitoniidae due to its elegant sculpture of regularly spaced, close-set and uniform varices. The finely pitted surface appearance of the varix tops we have not seen in any congener. Cirsotrema loerentheyi ( Boettger, 1902) differs in it cancellate sculpture and Cirsotrema crassicostanomalum ( Sacco, 1891) has broader varices overrun by spiral cords. We are not aware of comparable species from the Miocene of the northeastern Atlantic and Proto-Mediterranean Sea. Cirsotrema duciei ( Wright, 1855) , from the Langhian of Malta, has a comparable outline and close-set varices of similar width but differs in slenderer shell and spiral cords, which overrun the varices (see Wright 1855: pl. 7, fig. 3; Cilia 2024: pl. 3, figs J–M).
Paleoenvironment. At 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.