Dzikella, Kaim, 2004

Hansen, Thomas, 2019, Gastropods from the Cretaceous-Palaeogene boundary in Denmark, Zootaxa 4654 (1), pp. 1-196 : 90-91

Dzikella ? sp.

Fig. 24L

Material. Specimen MGUH 33146 is a fragmentary teleoconch mould.

Occurrence. Lithified top of the Højerup Member of the Maastrichtian Tor Formation north of Kulsti Rende.

Description. Teleoconch broadly coeloconoid with weakly convex, nearly flattened whorls with a strongly angular abapical keel and separated by somewhat grooved sutures. Whorl height approximating 2/5 the width. Base weakly convex. Columella smooth with no columellar fold. Whorls subrectangular in cross section.

Early teleoconch sculpture consisting of 12 to 18 coarse transverse ribs and fine spiral lirae. Transverse ribs reaching from adapical two spiral lirae and abapically to keel. Later teleoconch whorls smooth except for two weak adapical spiral lirae and two similarly weak abapical spiral lirae located slightly adapically of keel. Growth lines strongly prosocline, slightly prosocyrt.

Measurements. Specimen MGUH 33146 is 7.2 mm high and 6.0 mm wide, consisting of 6 ½ teleoconch whorls.

Remarks. The Danish taxon resembles the late Maastrichtian D. chukinensis Kaim, Beisel & Kurushin, 2004 from Western Sibiria, but differs by the concave sided spire, the more flattened whorls with the abapically located keel and by a less convex base.

Figures

FIGURE 24. A. Tenagodus sp., Silicone cast of MGUH 33139. Tube diameter 5.6 mm. B–D. Campanile selandicum (Lundgren, 1867). B–C. Silicone cast of MGUH 33140. Width 11.4 mm. D. Silicone cast of MGUH 33141. Width 4.5 mm. E–F. Campanile sp. A. Silicone cast of MGUH 33142. Whorl height 2.1 mm. G. Campanile sp. B. Silicone cast of MGUH 33143. Height 4.2 mm. H–K. Metacerithium balticum (Ravn, 1902). H. Silicone cast of protoconch MGUH 33144. Width 0.45 mm. I. Silicone cast of MGUH 33145. Height 26.0 mm. J. Silicone cast of lectotype MGUH 91 figured by Ravn (1902, pl. I: 17). Width 11.7 mm. K. Silicone cast of MGUH 93, figured type for Cerithium sartorii Ravn, 1902. Height 7.1 mm. L. Dzikella? sp., Silicone cast of MGUH 33146. Width 6.0 mm. M–Q. Amaurellina ravni n. sp. M–N. Silicone cast of holotype MGUH 33147. Width 10.3 mm. O. The internal mould of paratype MGUH 33148. Width 13.2 mm. P. Paratype MGUH 33149, a mould with replaced shell. Height 12.8 mm. Q. Silicone cast of paratype MGUH 33150. Width of picture 3.0 mm. R. Trochocerithium sp., Silicone cast of MGUH 33151. Width 9.0 mm. S–W. Galericulus sp. S–T. Internal mould ØSM.10042-311. Length 5.8 mm. U. Internal mould MGUH 33152. Width 8.5 mm. V–W. Internal mould and external cast of MGUH 33153. Length 10.3 mm. Width of figure W 7.7 mm. X. Natica sp. A. Silicone cast of MGUH 33154. Width 7.9 mm.