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
Eulima
?
danica
Ravn, 1933
Figs 26
Y–Z
1933
Eulima
(
Polygyreulima
)
danica
n. sp.
Ravn: 41, pl. IV, figs 1a–b, 2a–b.
2014
Eulima
(
Polygyreulima
)
danica
Ravn, 1933
—Lauridsen & Schnetler: 68, fig. 83A–D.
Diagnosis.
Shell relatively high, straight, with highly flattened whorls separated by nearly invisible sutures. Transition to base moderately convex.Aperture relatively high and narrow with very sharp upper angle and gently sigmoid inner side. Columellar lip distinct with evenly rounded outer margin. Outer lip gently sigmoid.
Material.
Material examined herein consists of
holotype
MGUH
3148 and
paratype
MGUH
3149 from the Danian ‘Naesekalk’, specimens
MGUH
33180,
MGUH
33181,
ØSM
.10042-313-a and b, three specimens from the informally catalogued samples SR.575, SH.141.A–B and SH.169.B, and five uncatalogued moulds from the lower Danian
Cerithium Limestone. The
latter specimens are deposited in the old collections at the Natural History Museum of
Denmark
.
Type
stratum and
type
locality.
The
middle
Danian
‘
Naesekalk’
at
Faxe Quarry
,
Sealand
,
Denmark
.
Occurrence.
Eulima
?
danica
is known from an unspecified level within the lower Danian
Cerithium Limestone Member
at Skeldervig and from the lower
10 cm
of the
Cerithium Limestone Member
at Højerup Church, Stevns Klint. The
type
material belongs to the middle Danian ‘Naesekalk’ in Faxe Quarry,
Denmark
. In addition a single specimen,
ØSM
.10042-313-a + b, is known from the ‘Krabbelaget’, a hardground located two metres up in the Korsnaeb Member. A further specimen in the collections of C. Heinberg comes from the lower Danian ‘dead layer’ at Vokslev, Northern Jutland.
Description.
Slender shell generally nearly straight, awl-shaped conical with a height corresponding to around 3.7 times the width. Protoconch consisting of 1 3/4 smooth and moderately convex whorls. Protoconch differing only slightly from teleoconch by a distinctly stronger whorl convexity. Teleoconch whorls relatively high and flat with a smooth surface except for the weak growth lines. A few moderately weak incremental scars may be present, while a false suture is absent or at most very faintly developed slightly below the shallow suture. Aperture high and narrow, the height corresponding to nearly 2.6 times the width. Outer lip straight in frontal view, in lateral view slightly prosocline, strongly projecting with strongest projection below mid-line. Base of aperture slightly pointed. Parietal callus thin but distinct. Umbilicus absent.
Measurements.
Shell of most complete specimen from the
Cerithium Limestone
,
MGUH
33180,
9.2 mm
high and
2.5 mm
wide with an aperture measuring
3.1 mm
in height and
1.2 mm
in width and consisting of 7 ½ teleoconch whorls. Last whorl
4.8 mm
in height.
Remarks.
Eulima
?
danica
could also belong to the closely related genus
Melanella
Bowdich, 1822
, but differs by the relative height of the aperture corresponding to nearly 2.6 times the width, whereas
Melanella
typically is characterized by an aperture H/W ratio of less than 2.4 (
Bouchet & Waren 1986
) and by a more convex outer lip profile (pers. comm. A. Warén, 2009). Another possible genus is
Polygyreulima
Sacco, 1892
, which generally is characterized by a relatively slender spire like the present species, but the very straight outer lip profile would rather suggest an assignment to
Eulima
(pers. comm. A. Warén, 2009).
Eulima
?
danica
resembles the Late Cretaceous
Eulima gracilistylis
Sohl, 1964a
and
E. persimplicata
(
Wade, 1926
)
from
Mississippi
,
USA
, but differs in the narrower aperture and, with regard to
E. gracilistylis
also in a less curved inner lip.
Recently
Lauridsen and Schnetler (2014
: p. 68) listed
paratype
MGUH 3149 figured in
Ravn (1933
: pl. IV: 2a–b) as the
holotype
. This is probably an error as
Ravn (1933)
himself stated the
holotype
to be the one figured on plate IV, fig. 1 (in other words specimen MGUH 3148).