Viennella, Harzhauser & Landau, 2019

Harzhauser, Mathias & Landau, Bernard, 2019, Turritellidae (Gastropoda) of the Miocene Paratethys Sea with considerations about turritellid genera, Zootaxa 4681 (1), pp. 1-136 : 77

Genus Viennella new gen.

Type species: Turritella incisaeformis Csepreghy-Meznerics, 1956 . Middle Miocene , Hungary .

Diagnosis. Shell small to moderately small, moderately slender. Protoconch comprising about 2.5 low, smooth, convex whorls of ~250 μm diameter. Order of appearance of primary spirals B-C-A. Secondary spiral cords rivalling primary cords in strength resulting in close-set spiral sculpture of 7–10 cords. Whorl profile flat sided to moderately convex on late teleoconch whorls with maximum diameter below mid-whorl; suture distinctly incised. Lateral sinus angle low to moderately steep; simple with faint inflection points, shallow to moderately deep. Discontinuous palatal and basal spiral lirae present in all known species.

Etymology. A combination of Vienna (referring to the occurrence in the Vienna Basin) and Turritella .

Included species. Turritella incisaeformis Csepreghy-Meznerics, 1956 (middle Miocene, Hungary, Austria); Viennella ignorata new sp. (middle Miocene, Hungary, Austria). Turritella bellardii Mayer, 1866 and T. laevissima Mayer, 1866 from the Burdigalian of the Torino Hills ( Italy) might belong here as well, but we have not seen the type specimens.

Stratigraphic and geographic range. Middle Miocene (Badenian) of the Central Paratethys. All records are reported so far only from the Vienna Basin ( Austria) and the Pannonian Basin ( Hungary).

Paleoenvironment. From the inner neritic with marly sand bottoms and seagrass to middle-outer neritic softbottom environments.

Discussion. The type species Viennella incisaeformis Csepreghy-Meznerics, 1956 has been placed in Turritella Lamarck, 1799 by Csepreghy-Meznerics (1956), Strausz (1966), and Báldi & Kókay (1970), which is surely incorrect. Aside from the distinctly smaller size of Viennella , the lateral sinus of Turritella is wider with steeper angle and lacks the faint inflection points of Viennella . Moreover, the order of appearance of primary spiral cords is B-A-C in Turritella but B-C-A in Viennella . This formula differs also from Oligodia and Peyrotia (B-D), Ptychidia (B-A-C) and Zaria and Haustator (C-B-A). Only Helminthia has the same order of appearance of primary spirals but differs in its larger size, the presence of three primary spiral cords and the characteristic secondary spiral sculpture covering the prominent primary cords. Turritellinella new gen. comprises also small to moderately small species but differs in its convex whorls and strongly differentiated primary, secondary and tertiary spiral sculpture. Viennella ignorata new sp. is provisionally placed in Viennella , based on ity similarity with the type species in sculpture, size and overall morphology; neanic whorls, however, are unknown so far.