Gattendorfia costata Vöhringer, 1960

Fig. 76; Table 74

Gattendorfia costata Vöhringer, 1960: 152, pl. 5 fig. 7.

Gattendorfia costata – Bartzsch & Weyer 1982: 19, text-fig. 4.2. — Korn 1994: 73, text-fig. 65c.

non Gattendorfia costata Vöhringer 1960: 152, text-figs 27, 37 (only). — Weyer 1977: 173, pl. 1 figs 1, 7. — House 1985a: 126, pl. 6.7.14 fig. d. — Gordon 1986: 18, text-figs 6.1–6.3, 8.3. — Korn 1994: 73, text-figs 66d, 67a (only). — Dzik 1997: 107, text-fig. 28f. — Korn & Weyer 2003: 100, text-fig. 14h–i. — Korn et al. 2003b: 1125, text-fig. 3b. — Sprey 2002: pl. 4 fig. 7.

Diagnosis

Species of Gattendorfia with a conch reaching 50 mm diameter. Conch at 30 mm dm thickly pachyconic, evolute (ww/dm ~0.80; uw/dm ~0.45). Whorl profile at 30 mm dm extremely depressed (ww/wh ~2.85); coiling rate very low (WER ~1.48). Venter broadly rounded, umbilical margin narrowly rounded. Without constrictions on the shell surface and without internal shell thickenings, with short ribs on the umbilical margin.

Material examined

Holotype

GERMANY • Rhenish Mountains, Oberrödinghausen, railway cutting; Hangenberg Limestone, bed 2; Vöhringer Coll.; illustrated by (Vöhringer 1960: pl. 5 fig. 7), Korn (1994: text-fig. 65c) and Sprey (2002: pl. 4 fig. 7); re-illustrated here in Fig. 76; GPIT-PV-63941.

Description

Holotype GPIT-PV-63941 is a rather poorly preserved specimen with 32 mm diameter of the conch (Fig. 76). It is partly ground and therefore shows hardly any remains of the shell. The conch is barrelshaped (ww/dm = 0.84) with a very broadly rounded venter, a rather narrowly rounded umbilical margin and a convex umbilical wall. The umbilicus is rather wide (uw/dm = 0.44) and the coiling rate is very low (WER = 1.49). Little can be said about the ornament; short, blunt riblets are formed on the umbilical margin.

Remarks

Vöhringer (1960) merged at least three morphological easily distinguishable species under the name Gattendorfia costata . (1) The first of these, defined by the holotype, is characterised by a wide umbilicus (uw/dm ~0.45) and weak nodes on the raised umbilical margin. (2) The second of these species, described here as G. corpulenta sp. nov., has a much narrower umbilicus with a uw/dm ratio of ~0.30, such as the cross section which he published (Vöhringer 1960: text-fig. 27) and short backwardly directed ribs. (3) The third, not explicitly mentioned by Vöhringer (1960) and described here as Zadelsdorfia oblita sp. nov., also has a much narrower umbilicus (uw/dm = 0.30) and lacks ribs but possesses concavo-convex internal shell thickenings. Another separating criterion to distinguish between G. costata and G. corpulenta is the course of the constrictions, which are concavo-convex with a ventrolateral projection and a rather narrow ventral sinus in G. costata but with convex course without ventrolateral projection and with broad ventral sinus in the new species G. corpulenta .