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
Fusinus schnetleri
n. sp.
Figs 30
L–M
Diagnosis.
Teleoconch moderately slender with eight strongly convex and rounded transverse ribs per whorl, the ribs forming weak rounded shoulder. Transverse ribs crossed by sharp spiral riblets with moderately broad interspaces.
Derivation of name.
In honour of K.I. Schnetler, who has contributed much to our knowledge of the Cainozoic gastropod faunas from
Denmark
.
Type material.
Holotype
MGUH 33251
is an external and internal mould lacking protoconch
.
Paratype
MGUH 33252
is a teleoconch from the dead layer in
Dania Quarry
,
Northern Jutland
.
Additional material.
Five external moulds from Stevns Klint are located in the collections of the National History Museum of
Denmark
. A mould catalogued by the informal sample number DN.9.A–B comes from Dania Quarry, Northern Jutland. Another three specimens from the same locality and belonging to the private collection of K.I. Schnetler have been examined.
Type
stratum and
type
locality.
Cerithium Limestone Member
south of
Stevns Fyr
,
Stevns Klint
.
Occurrence.
Sporadically occurring in the
Cerithium Limestone Member
along the southern part of Stevns Klint (Skeldervig to slightly south of Stevns Fyr) and contemporaneous dead layer in Dania Quarry, Northern Jutland.
Description.
Protoconch unknown. Teleoconch moderately high-spired, consisting of weakly convex whorls; whorls low, their height corresponding to nearly half their width. Narrow suture located in distinct angle between succeeding whorls, or slightly below widest part of preceding whorl. Height of last whorl corresponding to around 60 % of shell. Aperture elongated ovoid with moderately gradual transition to narrow siphonal canal. Inner and outer lips and columella smooth, with no folds.
Teleoconch sculpture dominated by around eight strong, rounded transverse ribs partly aligned from whorl to whorl. Ribs giving the whorls a more convex outline. Interstices wider than ribs. Spiral riblets strong and sharp; strongest and least crowded four ribs running at whorl periphery. Around four smaller ribs are located between these and adapical suture on some specimens, while others have fewer and stronger ribs. Transverse ribs fading out at transition to base, which is dominated by close lying spiral riblets, becoming gradually finer towards distal end of canal.
Measurements.
Most complete specimen,
MGUH
33252,
13.6 mm
high and
6.2 mm
wide, consisting of initial six teleoconch whorls, but lacking tip of siphonal canal.
Remarks.
This taxon differs from the middle Danian
Fusinus faxensis
(
Ravn, 1902
)
from Faxe Quarry,
Denmark
, by the slightly stronger and more closely spaced transverse ribs and the less crowded spiral riblets. It resembles the Early Palaeocene
Fusinus
sp. (sensu
Kollmann & Peel 1983
) from
Greenland
, but differs by a less tapering siphonal canal and a slightly more compact spire.
It appears distinctly more common in the ‘dead layer’ of Northern Jutland than in the
Cerithium Limestone
of Stevns Klint, suggesting a preference for a more deep-water and muddy environment than inhabited by most of the gastropods from the Danish area.