Sveltia suessi ( Hoernes, 1875 )

Harzhauser, Mathias & Landau, Bernard, 2012, A revision of the Neogene Cancellariid Gastropods of the Paratethys Sea 3472, Zootaxa 3472, pp. 1-71 : 52

Sveltia suessi ( Hoernes, 1875)

Figs 10C 1–C 3, 10D 1–D 3

Cancellaria Suessi Hoernes, 1875: 355 , pl. 11, figs 22–23.

Cancellaria (c. Narona ) Suessi R. Hoern. — Hoernes & Auinger 1890: 279, pl. 35, figs 8–9.

Cancellaria (Sveltia) suessi R. Hörn. — Sieber 1956: 317.

Cancellaria (Sveltia) suessi R. Hoern. — Aberer 1958: 57.

Narona (Sveltia) suessi (R. Hoernes et Auinger) — Hölzl 1973: 194.

Narona (Sveltia) suessi (R. Hoernes, 1875) — Steininger 1973: 435, pl. 8, figs 1–2.

Sveltia suessi Hoernes — Rupp 2008: 19.

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

Studied and illustrated material. Figs 10D 1–D 3: syntype illustrated in Hoernes (1875, pl. 11, figs 22a–b) and in Hoernes and Auinger (1890, pl. 35, figs 8a–b), Ottnang ( Austria), height: 27.8 mm, width: 13.3 mm, GBA 1875/ 001/0019/1. Figs 10C 1–C 3: syntype illustrated in Hoernes (1875, pl. 11, figs 23a–b) and in Hoernes and Auinger (1890, pl. 35, figs 9a–b), Ottnang ( Austria), height: 22.9 mm, width: 14.1 mm, GBA 1875/001/0019/2 (= holotype of Sveltia Suessi var. postypica Sacco, 1894, p. 58 ).

Discussion. This species is clearly closely related to Sveltia dertovaricosa Sacco, 1894 . A separation is based on the fusiform outline, which lacks an angulation, on the shorter spire and on the reduced axial ribs, which bear small nodes at the intersections with the spiral ribs. This sculpture is comparable with that of Sveltia colpodes Cossmann, 1899 , from the Langhian of the Aquitaine Basin, which is more slender and has a higher spire.

A further argument to treat this taxon as valid species is the fact that the Paratethys was strongly isolated during middle Burdigalian times, resulting in a high Ottnangian endemism rate ( Harzhauser & Piller, 2007; Landau et al., 2009). It is thus not surprising that Sveltia suessi might have formed as offshoot from the Sveltia lyrata -group. Middle Miocene occurrences as mentioned by Kittl (1887) need confirmation.

The material from the Ottnangian of Upper Austria as described by Hoernes (1875) is always slightly deformed and poorly preserved. The specimen illustrated as fig. 9 by Hoernes and Auinger (1890, pl. 35) is deformed as well and lacks the anterior termination. Therefore, a separation as a distinct taxon postypica Sacco, 1894 is superfluous and was probably caused by the misleading illustration in Hoernes and Auinger (1890).

Distribution. Seemingly restricted to the Ottnangian (Middle Burdigalian) of the Paratethys.

Paratethys —Ottnangian: North Alpine Foreland Basin ( Austria: Ottnang and various other localities in Upper Austria; Bavaria: Gernergraben, Kaltenbachgraben).