Perrona loetschi Harzhauser & Landau & Janssen 2022, nov. sp.
Creators: name: Harzhauser, Mathias
name: Landau, Bernard
name: Janssen, Ronald
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Neogastropoda
Clavatulidae
Perrona
Perrona loetschi

description: Perrona loetschi nov. sp.   
 Figs 32A 1 –A 3, B 1 –B 2, C 1 –C 3, D 1 –D 2, 5, 7   
 Pleurotoma Jouanneti [sic] Des Moul.— Hörnes 1854: 346 (partim), pl. 38, figs 4a–b [non Tomellana jouannetii (Des Moulins, 1842)].   
 Pleurotoma (Clavatula) descendens Hilb. — Hoernes & Auinger 1891 (partim): 355, pl. 48, figs 7–8 [non Perrona descendens (Hilber, 1879)].   
 Type material. Holotype: NHMW 1949 /0005/0102a, SL: 30.1 mm, MD: 13.5 mm, Grund (Austria), illustrated in Hoernes & Auinger (1891, pl. 48, fig. 8), Figs 32A 1 –A 3. Paratypes: NHMW 1949 /0005/0102b, SL: 28.4 mm, MD: 12.1 mm, Grund (Austria), illustrated in Hoernes & Auinger (1891, pl. 48, figs 7a–b), figs 32B 1 –B 2; NHMW 1855 /0045/0752, SL: 28.0 mm, MD: 12.1 mm, Grund (Austria), illustrated in Hörnes (1854, pl. 38, figs 4a–b), figs 32D 1 –D 2; NHMW 2021 /0153/0001, SL: 31.3 mm, MD: 13.6 mm, Grund (Austria), figs 32C 1 – C 3; NHMW 2021 /0153/0002, 31 spec., Grund (Austria); NHMW 1855 /0045/0752, 15 spec., Grund (Austria); NHMW1860 /0050/0059, 2 spec., Neuruppersdorf (Austria), SMF 351872 /5, Grund (Austria).   
 Type locality. Grund (Austria); North Alpine-Carpathian Foreland Basin.   
 Type stratum. Silty sand of the Grund Formation.   
 Age. Middle Miocene, early Badenian (early Langhian).   
 Etymology. In honor of Bernd Lötsch, Director General of the Natural History Museum in Vienna from 1994 to 2009.   
 Diagnosis. Perrona species of medium size, very solid, broad fusiform, with gradate spire, subcylindrical whorls with strongly swollen, weakly tuberculose subsutural collar. Absence of well-defined suprasutural cord. Much reduced spiral sculpture and relatively short siphonal canal.   
 Description. Shell medium-sized, very solid, broad fusiform with markedly gradate spire; apical angle 38–45°. Protoconch not preserved. Teleoconch of nine whorls. Early teleoconch whorls weakly concave with two narrow, adsutural spiral cords separated by weakly concave central part with close-set opisthocline, comma-shaped axial riblets. Axial riblets fading out on fourth whorl. Later whorls subcylindrical with prominent, sharply-delimited, swollen, rounded subsutural collar bearing poorly defined tubercles, weakly convex below, suprasutural cord very weak, almost entirely covered by succeeding whorl. Delicate spiral cords on spire whorls (rarely preserved in available material). Suture narrowly incised, linear. Last whorl ~65% of total height, subcylindrical. Subsutural collar very broad and swollen, rounded, weakly beaded. Subsutural ramp very narrow, weakly concave. Shoulder rounded, weakly convex below, weakly angled at moderately constricted and concave base. Siphonal fasciole moderately swollen with prominent growth increments. Sculpture extremely weak, fine indistinct cords over base and fasciole. Aperture moderately wide, pyriform. Outer lip not thickened, smooth within; anal sinus moderately deep, moderately narrow, asymmetrically U-shaped, with apex mid-ramp. Siphonal canal moderately long, moderately wide, only slightly deflected to the left with shallowly notched tip. Columella excavated in upper third, straight below, weakly twisted at fasciole, smooth. Columellar and parietal callus thick, sharply delimited, forming broad rim and narrow pseudumbilical chink.   
 Discussion. This species was confused by Hörnes (1854) with Tomellana jouannetii (Des Moulins, 1842), from the Burdigalian of Mérignac in France, and by Hoernes & Auinger (1891) with Perrona descendens (Hilber, 1879) from the Badenian of the Paratethys Sea. The separation from Tomellana jouannetii is obvious based on the gradate spire, the irregularly beaded subsutural collar (see Peyrot 1931, pl. 8, figs 43, 61, 62, 66, 71) and the early teleoconch sculpture (see discussion on Tomellana). The separation from Perrona descendens is less obvious at first sight. Nevertheless, Perrona loetschi differs in its more solid, broader shell, shorter spire, the broader ‘shelf’ of the subsutural collar, the lower penultimate whorl and higher last whorl, and the much reduced spiral sculpture. The broad outline and the absence of distinct spiral cords on the entire teleoconch allow also a separation from Perrona vindobonensis (Quenstedt, 1884) and P. ilonae nov. nom. Perrona louisae (Hoernes & Auinger, 1891) has even broader whorls and differs in its pointed beads.   
 Paleoenvironment. At the locality Grund fossiliferous channel fills, which formed in middle to outer neritic environments bear allochthonous assemblages uniting coastal-mudflat faunas with inner neritic ones (Zuschin et al. 2005; Roetzel 2009). Preservation and color of the shells, suggest, that Perrona loetschi belonged to the allochthonous shallow water fauna and not to the autochthonous deep-water fauna.   
 Distribution in Central Paratethys. Karpatian (early Miocene): North Alpine-Carpathian Foreland Basin: Neuruppersdorf (Austria) (hoc opus); Badenian (middle Miocene): North Alpine-Carpathian Foreland Basin: Grund (Austria) (Hoernes & Auinger 1891).
description: Published as part of Harzhauser, Mathias, Landau, Bernard & Janssen, Ronald, 2022, The Clavatulidae (Gastropoda, Conoidea) of the Miocene Paratethys Sea with considerations on fossil and extant Clavatulidae genera, pp. 1-172 in Zootaxa 5123 (1) on page 109, DOI: 10.11646/zootaxa.5123.1.1, http://zenodo.org/record/6399827