Scalptia dertoparva ( Sacco, 1894 ) Harzhauser & Landau, 2012

Harzhauser, Mathias & Landau, Bernard, 2012, A revision of the Neogene Cancellariid Gastropods of the Paratethys Sea 3472, Zootaxa 3472, pp. 1-71 : 38-39

Scalptia dertoparva ( Sacco, 1894) nov. comb.

Figs 3N, 8C 1–C 3

Cancellaria scabra Desh. —Hörnes 1856: 681, pl. 52, figs 7a–b [non Cancellaria scabra Deshayes, 1830 ].

Cancellaria (M. Trigonostoma) scabra Desh. — Hoernes & Auinger 1890: 277 [non Cancellaria scabra Deshayes, 1830 ]. Cancellaria (Trigonostoma) scabrum variet dertoparva Sacco, 1894: 7 .

Cancellaria (Trigonostoma) scabra Desh. — Sieber 1936: 87 [non Cancellaria scabra Deshayes, 1830 ].

Cancellaria (Trigonostoma) scabra Desh. — Sieber 1947: 157 [non Cancellaria scabra Deshayes, 1830 ].

Trigonostoma sp. — Brunetti et al. 2011: 114, fig. 16E.

Type material. NHM Vienna ( Austria); see below for details .

Studied material. 4 spec. Gainfarn ( Austria) NHMW 2009 z0098/0022, NHMW 1866 /0001/1246.

Illustrated material. Fig. 3N: Gainfarn ( Austria), height: 23.6 mm, width: 17.2 mm, NHMW 1866/0001/1246.

Figs 8C 1–C 3: specimen illustrated in Hörnes (1854, pl. 52, figs 7a–b), Gainfarn ( Austria), height: 26.1 mm, width: 20.5 mm, NHMW 2009 z0098/0022, holotype of Trigonostoma scabrum var. dertoparva Sacco, 1894 .

Discussion. The shells are characterised by a rather stocky outline with gradate spire. The slightly prosocline axial ribs are strongly raised and crossed by sharp and raised spiral cords, intercalated by secondary and tertiary threads. The axials cause a conspicuous spoke-wheel-like sculpture in apical view and develop weak spines at the shoulder. Three prominent folds appear on the columella and the deep posterior canal is bordered medially by a prominent parietal denticle and laterally by the adapical lira on the outer lip. This species was erroneously treated as Cancellaria scabra Deshayes, 1830 by most authors. The Pliocene C. scabra is a junior synonym of Voluta umbilicaris Brocchi, 1814 (= Trigonostoma umbilicare ) and differs distinctly in its much wider umbilicus and the predominant spiral sculpture, lacking the strong and oblique axial ribs of the Miocene species [see Chirli (2002) and Landau et al. (2006) for comparison]. Without defining any conchological features, Sacco (1894) proposed the variety-name dertoparva for the Viennese shell, referring explicitly to the specimen illustrated as fig. 7 in Hörnes (1856, pl. 52). The narrow umbilicus and the presence of three strong columellar folds suggest a generic assignment within Scalptia rather than within Trigonostoma ( Petit 1980, Beu & Raine 2009).

Scalptia dertoparva is probably closely related to Scalptia burdigalensis ( Peyrot, 1928) from the Burdigalian of the Aquitaine Basin in France (see Cahuzac et al. 2004). Both species agree in overall shape and sculpture but can be distinguished based on the narrower umbilicus and the stronger columellar folds of Scalptia dertoparva ( Sacco, 1894) . The specimen illustrated by Mikuž (2009) as Trigonostoma umbilicaris ( Brocchi, 1814) from the Badenian of the Krka Basin in Slovenia is neither conspecific with the Pliocene species nor with Scalptia dertoparva from which it differs in its high and scalate spire and the wider umbilicus. It might rather represent a still undescribed Paratethyan Trigonostoma species.

Distribution. A very rare species known so far only from the Paratethys.

Paratethys —Badenian: North Alpine Foreland Basin ( Austria: Windpassing); Vienna Basin ( Austria: Gainfarn).