Wormsina, Harzhauser & Landau, 2021

Harzhauser, Mathias & Landau, Bernard, 2021, The Mitridae (Gastropoda: Neogastropoda) of the Miocene Paratethys Sea, Zootaxa 4983 (3), pp. 1-72 : 49

Genus Wormsina nov. gen.

Type species. Mitra (Cylindra) transsylvanica Hoernes & Auinger 1880 . Middle Miocene , Romania, Paratethys Sea .

Diagnosis. Mitridae of medium size, ovoid, with low dome-shaped spire, high last whorl, cancellate sculpture on early spire whorls, pitted spiral grooves on adapical part of last whorl, columella with four folds, callus restricted to area from siphonal canal to adapical columellar fold.

Description. See description of type species.

Etymology. Referring to the World Register of Marine Species WoRMS (http://www.marinespecies.org/).

Included species. Only the type species is known.

Stratigraphic and geographic range. Only known so far from middle Miocene (Badenian) deposits of the southern Central Paratethys Sea, recorded from Romania.

Palaeoenvironment. Unknown.

Discussion. The Miocene type species of Wormsina was placed in the genus Dibaphimitra Cernohorsky, 1970 by Cernohorsky (1970, 1976). Mitra florida Gould, 1856 , the type species of Dibaphimitra, is an extant species living in Florida and the Caribbean, and is the only living representative of the genus. The systematic status of Dibaphimitra within the Mitridae is so far unsolved ( Fedosov et al. 2018). Morphologically, Dibaphimitra is reminiscent of Wormsina concerning the unusual ovoid outline, which might have been the main reason for Cernohorsky (1970, 1976) to discuss the Paratethyan species under Dibaphimitra. Aside from this superficial similarity, however, the genera differ substantially. The spire of Wormsina is cyrtoconoid dome-shaped, as opposed to conical and comparatively high in Dibaphimitra. Wormsina attains only half the height of Dibaphimitra, its columella bears a conspicuous callus extending from the adapical fourth columellar to the siphonal canal, whereas the columella in Dibaphimitra is not callused and bears six to seven folds, which are “ rather small for the size of the shell ” ( Cernohorsky 1976: 473). In addition, the axial sculpture on early spire whorls and the pitted spiral grooves of Wormsina are unknown from Dibaphimitra. Lastly, its colour pattern of spirally arranged dots and dashes ( Figs 10F 1 –F 2 , G 1 –G 2 )differs from the large blotches of Wormsina .

Hoernes & Auinger (1880) placed this species in Cylindra Schumacher, 1917 [non Illiger, 1802, Coleoptera ], which is currently treated as Pterygia Röding, 1798 ( Fedosov et al. 2018). The genus Pterygia differs from Wormsina in its proportionally higher last whorl and the deeply incised anal canal. In addition, it bears six to eight columellar folds.

Figures

FIGURE 1. A. Map of central and south–eastern Europe, representing the area that was partly covered by the Central Paratethys Sea (for detailed maps with the localities mentioned in the text see Kroh (2005) and Nosowska (2020). The white insert corresponds to the area that is restored in the palaeogeographic map below. B. Palaeogeography of the Middle Miocene Paratethys Sea (modified from Harzhauser & Landau 2017) showing the most important sedimentary basins (NAFB: North Alpine Foreland Basin, E–Sopr B: Eisenstadt–Sopron Basin).

FIGURE 2. Measurements for shell morphology and whorl profiles. SL: shell length, MD: maximum diameter, AA: apical angle, LWH: last whorl height, AH: aperture height. AL: aperture length. AW: aperture width. S: length of siphonal canal.

FIGURE 10. A1–A2. Fraudiziba mathiasi (Bałuk, 1997), Lăpugiu de Sus (Romania), NHMW 1854/0035/0085. B1–B2. Fraudiziba subcarinata (Bellardi, 1887), Modra-Kráľová (Slovakia), NHMW 2020/002/0001. C. Fraudiziba subcarinata (Bellardi,