Gastropods from the Cretaceous-Palaeogene boundary in Denmark
Author
Hansen, Thomas
text
Zootaxa
2019
2019-08-12
4654
1
1
196
journal article
26049
10.11646/zootaxa.4654.1.1
9ce1d103-9234-4fbe-9544-f1c294bb8783
1175-5326
3365803
CFD82CC0-3110-472E-972B-7ADC0C523A04
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.