Claviscala, Boury, 1909

Hansen, Thomas, 2019, Gastropods from the Cretaceous-Palaeogene boundary in Denmark, Zootaxa 4654 (1), pp. 1-196 : 129

Claviscala sp.

Fig. 29R

Material. A single external mould, MGUH 33238, lacking protoconch and aperture.

Occurrence. The Cerithium Limestone at Vokslev Quarry in northern Jutland.

Description. Teleoconch spire acutely conical, whorls weakly convex, relatively high, the height corresponding to 65 % of the width; whorls constricted just above abapical suture. Suture located just abapically of outer sharp margin of basal disc. Transition to smooth flat basal disc sharp, marked by subperipheral carination. Aperture not known.

Teleoconch sculpture consisting of sharp crested, inverted sigmoid transverse ribs numbering around 16 on sixth whorl, while increasing to 30 on 11 th whorl; ribs starting slightly abapically of adapical suture, reaching all the way down to the basal disc. A shoulder or adapical tubercle appears on adapical end of ribs on later whorls. No spiral ribs present.

Measurements. Preserved teleoconch 7.1 mm high and 1.4 mm wide, consisting of 11 teleoconch whorls.

Remarks. The taxon differs from the Maastrichtian C. minor n. sp. described above by the wide spiral band without transverse ribs on the adapical part of the whorls and the more sigmoid form of the transverse ribs.

Figures

FIGURE 29. A–B. Ageria skeldervigensis n. sp., Silicone cast of holotype MGUH 33226. Width 3.8, 4.5 mm respectively. C–E. Ageria laxa n. sp. C–D. Silicone cast of holotype MGUH 33227. Width 4.6 mm for teleoconch, 0.3 mm for protoconch. E. Silicone cast of paratype MGUH 33228. Width 6.7 mm. F–G. Ageria sp. F. Silicone cast of seemingly mislaid specimen MGUH 33229. Width 3.7 mm. G. Silicone cast of MGUH 33230. Width 0.6 mm. H–K. Coniscala umbilica n. sp. H. Silicone cast of paratype MGUH 33231. Width 1.4 mm. I–J. Holotype MGUH 33232. Width 19.6 mm. K. Paratype MGUH 33233. Width 12.4 mm. L–N. Opalia sp. L–M. Silicone cast of MGUH 33234. Width 1.3 mm. N. Silicone cast of MGUH 33235. Width 0.5 mm. O–Q. Claviscala minor n. sp. O–P. Silicone cast of holotype MGUH 33236. Width of teleoconch 0.9 mm. Width of protoconch 0.4 mm. Q. Silicone cast of paratype MGUH 33237. Width 1.3 mm. R. Claviscala sp., Silicone cast of MGUH 33238. Width 1.4 mm. S–V. Amaea aliceae n. sp. S–U. Silicone cast and inner mould of holotype MGUH 33239. Width 2.7, 2.0 and 3.1 mm respectively. V. Silicone cast of paratype MGUH 33240. Width 1.7 mm. W. Amaea stevniensis n. sp., Silicone cast of holotype MGUH 33241. Width 1.0 mm. X. Amaea sp. A. Silicone cast of MGUH 33242. Width of teleoconch 1.1 mm.