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
Zebinella selandica
n. sp.
Figs 25
S–U
Diagnosis.
Shell slender with rounded apex, moderately convex whorls and well defined transverse ribs terminating at the whorl periphery. Transverse ribs numbering around 20 on first teleoconch whorl. Suture line well impressed.
Derivation of name.
Refers to the Danish island Sealand from where it derives.
Type material.
Holotype
MGUH 33162
is a nearly complete external mould.
Additional material.
The collections at the Natural History Museum of
Denmark
includes 11 moulds with the unofficial sample numbers SH.12, SR.730, SR.745, SR.746.A, SR.748.B–C, SR.1043.A, SR.1047, SR.1063, SR.1089.A, SR.1093 and SR.1126.
Type
stratum and
type
locality.
Lithified
top of the
Højerup Member
of the
upper Maastrichtian Tor Formation
at
Rødvig
,
Stevns Klint
.
Occurrence.
Lithified top of the Højerup Member of the Maastrichtian Tor Formation at Rødvig and Højerup, Stevns.
Description.
Shell small to medium-sized, slender with an elongated conical spire. Protoconch obtusely conical,
0.55 mm
high and
0.55 mm
wide, consisting of approximately 3 ¾ smooth, convex whorls. Transition to teleoconch moderately sharp.
Teleoconch with weakly convex whorls more than twice as wide as high and divided by moderately deeply impressed linear suture located immediately abapically of preceding whorl periphery. Last whorl corresponding to less than half the shell height. Base convex. Aperture slightly flaring with thickened outer lip. Abapical part of aperture and columella not known. Teleoconch sculpture consisting of closely spaced, fine and slightly opisthocline, weakly opisthocyrt transverse ribs reaching from adapical suture to whorl periphery; number of ribs just surpassing 20 on first teleoconch whorl increasing to about 40 on third whorl. Base covered by weak spiral lirae, around nine on third whorl.
Measurements.
Holotype
MGUH
33162
0.8 mm
wide and
2.1 mm
high, consisting of protoconch and 3 ½ teleoconch whorls.
Remarks.
Zebinella selandica
n. sp.
differs from the two Selandian taxa figured by
Kollmann & Peel (1983)
as
Zebinella
sp. 1 and
Z
. sp. 2 from
Greenland
by the teleoconch sculpture with the transverse ribs terminating at the periphery and by the more rounded outline of the spire top. It differs from the Danian
Z
.
nuda
Briart & Cornet, 1887
and
Z
.
tenuicancellata
Briart & Cornet, 1887
from
Belgium
by the presence of distinct teleoconch sculpture and well impressed suture line (see
Cossmann 1924
;
Glibert 1973
). The lack of both of these characters may indicate that the two Belgian species most likely do not belong to this subgenus.