Paleocene molluscs from Nuussuaq, West Greenland
In the course of 18 expeditions to West Greenland during the years 1938 - 1939
and 1946 - 1968 a large material of Paleocene molluscs was collected by the late
professor Alfred Rosenkrantz and his co-workers. Rosenkrantz (1971) established
a few new species. 1983 Kollmann & Peel published an inventory of the gastropod
fauna, without establishing new species. Pacaud & Schnetler (1999) established
three new species. Schnetler & petit (2010) published a revision of the gastropod
family Cancellariidae and established one new genus and 18 new species.
Kollmann, H.A. & Peel, J.S., 1985: Paleocene gastropods
from Nûgssuaq, West Greenland. – Grønlands Geologiske Undersøgelse, Bulletin No.
146. 115 pp.
Pacaud,
J.- M. & Schnetler, K.I., 1999: Revision of the gastropod family Pseudolividae from the Paleocene of
West Greenland and Denmark. – Bulletin of the Geological Society of Denmark, 46,
53–67, 3 figs, 4 pls.
Rosenkrantz, A., 1970: Marine Upper
Cretaceous and lowermost Tertiary deposits in West Greenland. Meddelelser fra
Dansk Geologisk Forening 19, 406–453.
Schnetler,
K.I., & Petit, R.E., 2010: Revision of the gastropod family
Cancellariidae from the Paleocene of Nuussuaq, West Greenland.
– Cainozoic Research
7(1-2), pp. 3–26.
New molluscs from the Gram Clay.
In the first volume of the book treating the fossils of the
Late Miocene of Gram the molluscs are treated. 128 species are recognized from
the Gram
Clay in the clay-pit and in the Gram 1 borehole 5.30 - 16.50 m. 7 new taxons are
introduced, and 5 new species are established:
* Mesopelex
anderseni
* Nassarius (Tritonella) ronaldjansseni
* Teretia guersi
* Daphnella abrahamssoni
* Turbonilla (Strioturbonilla) rothi
Leif Banke Rasmussen
(1968) suggested that the Turbonilla - species was undescribed,
without establishing a new species..
The new study separates the well-known Gram species Galeodea echinophora
from the Pliocene and Recent Mediterranean Galeodea
echinophora. The Gram species is interpreted as a subspecies of the Pliocæne Galeodea bicatenata from
the Nord Sea Basin. The new name of the Gram species is Galeodea bicatenata
marqueti. The name is honouring the Belgian palaeontologist Robert Marquet,
who was the first to suggest to separate the Gram species from the genuine Galeodea echinophora (established
by Linné).
Leif Banke Rasmussen (1968) described and illustrated an
unidentified gastropod species as Gastropoda non det. 1. I succeeded in
identifying this species with Skenea minuta A.W. Janssen, 1967 from the Miocene
at Dingden in Germany.
Unfortunately this name was already given to a Recent Mediterranean Skenea
species by Jeffreys (1883), and consequently a new name for the Miocene Skenea
was necessary. The Miocene species got the name Skenea ariejansseni.
5 new species:
Mesopelex
anderseni, Nassarius (Tritonella) ronaldjansseni, Turbonilla (Strioturbonilla) rothi, Daphnella abrahamssoni
and
Teretia guersi.
Litteratur:
Schnetler,
K.I. 2005: The
Mollusca from the stratotype of the Gram Formation (Late Miocene, Denmark).
– in: Roth, F. & Hoedemakers (eds.) The Geology and
Palaeontology of the Gram Formation (Late Miocene) in Denmark, 1. Palaeontos
7, 62–190. Mortsel.
New gastropods from Fakse
Previous work
Many gastropod species have been recorded from the classical locality Fakse
Chalkpit. In the corallian limestone gastropods as a rule are preserved as
external impressions and internal moulds. Previously especially the internal
moulds were collected, while the impressions were overlooked. For a
determination, however, the impressions are important, because they allow fine
silicone rubber casts.
The great Danish palaeontologist and for many years inspector of the Geological
Museum of Copenhagen, Dr J.P.J. Ravn, 1902 described gastropods, bivalves and
nautils from the Danish Cretaceous. Ravn considered the chalk from Fakse, as
well as the Cerithium Chalk in Stevns, as Cretaceous deposits. Schilder (1928)
described the Cypraeacea from Fakse.
An unconsolidated soft chalk, often informally named "nose-chalk", has been
encountered several times. It contains well preserved gastropods. The original
aragonite has been transformed into calcite. The amateurgeologist K. Brünnich Nielsen
was the first to mention this fauna of small gastropods (1919).
Ravn (1933) revided his 1902 paper, and in his paper he treated the "nose-chalk"
material, collected by K. Brünnich Nielsen and the later professor Alfred
Rosenkrantz. Ravn established many new species.
Sten Lennart Jakobsen and Søren Bo
Andersen collected a large material in 1972, and in the 1990es Alice Rasmussen
collected much more material. German palaeontologists also studied nose-chalk
material, and Alexander Nützel (1997) and Klaus Bandel (1998) established new
species from Fakse.
In cooperation with the French palaeontologists Pierre Lozouet and
Jean-Michel Pacaud I 2001 published a small paper, treating the family
Scissurellidae in Fakse. Now five species of this rare family are known. All
representatives are small (1 - 2 mm) with a selenizone. Ravn recognized only one
species, and Bandel (1998) established one further species. Thus we could
establish three new species.
Revision of the Cancellariidae
In 2006 I published a revision of the family Cancellariidae from Fakse, made
in cooperation with R.E. Petit, U.S.A.
The superfamily Cancellarioidea contains c. 100 genera with more than 1800
Recent or fossil species (Petit & Harasewych, 1990). Cancellaridae have 2 - 3 folds
on the columella and a sculpture of almost equal strong spiral and axial ribs,
resulting in a cancellate sculpture. Ravn (1933) referred three species to this
family, except for Admete ?
biplicata all very rare.
During the study of the Selandian (Paleocene) molluscs of Sundkrogen, Copenhagen
I was contacted by Mr R.E. Petit, and soon the study of the family
Cancellariidae was started. The Sundkrogen fauna contained several common
representatives of the Cancellariidae. Richard E. Petit from South Carolina, U.S.A.
has for more than 35 years been studying the family Cancellariidae. The revision
of the Cancellariidae from Fakse confirms that representatives of this family
are rare. Yet 8 species were recognized, 6 of them were undescribed.
Plesiotriton steni and Unitas aliceae. Left photo by Leif Rasmussen, Fakse.
The SEM-photo to the right by Erik Thomsen, Geologisk Institut, Århus. Both
specimens collected by Alice Rasmussen.
The illustrated specimens above made an establishment of the new species
possible, as other adult specimens had no well preserved protoconchs. The two
specimens became paratypes and in 2005 they were designated "danekræ". A
remarkable sinistral gastropod of the family Cirroidea, also collected by Alice
Rasmussen, was the first Fakse gastropod among the "danekræ".
Three specimens of the new species Tatara danica. To the left the
holotype,
in the middle a specimen from the collection of Alice Rasmussens, Fakse and to
the right a silicone rubber cast of a paratype (height 25 mm, two other
specimens have a height of c. 10 mm). The holotype and the paratype were
collected by Søren Bo
Andersen in 1972. The genus Tatara has a very characteristic aperture
with denticles on both the columella and the internal of the labrum.
The genus Tatara was until now only known
from the Eocene and Miocene of New Zealand. The genus
Semitriton was until now known from the Eocene of Australia and France only.
These two genera have consequently their oldest representatives in the Danian of
Fakse. A possible explanation of the appearence of these two genera might be a
sea connection between the North Sea Basin and the Australian-New Zealandic
region during the Danian time. This connection thus is considerably older than
the connection between Tasmania and Crown Prince Frederik!
Semitriton biplicatus (Ravn, 1902), Admetula faksensis, Admetula
rosenkrantzi, Unitas anderseni and Unitas aliceae. Heights 9.8 mm, 10.3 mm, 6.7 mm, 7.5 mm og 8.8 mm
respectively.
Frequency of the 6 new species
Semitriton biplicatus (Ravn, 1902) is rather common, whereas only one
specimen of the last species of the 8 Cancellariidae (a Unitas)
is known.
Acknowledgements
Alice Rasmussen, Fakse, Søren Bo Andersen, Århus and Sten Lennart Jakobsen,
København kindly placed their collections at my disposal.
Litteratur
Bandel. K. 1998:
Scissurellidae als Modell für die Variationsbreite einer natürlichen Einheit
der Schlitzbandschnecken (Mollusca, Archaeogastropoda). Mitteilungen aus dem
Geologisch-Paläontologischen Institut der Universität Hamburg 81, 1-120.
Nielsen, K.B. 1919:
En Hydrocoralfauna fra Faxe. Meddelelser fra Dansk geologisk Forening 19, 5-63.
Nützel, A. 1997:
Über die Stammgeschichte der Ptenoglossa (Gastropoda). Berliner Geowissenschaftliche Abhandlungen E 26, 229 pp., 35 plates.
Petit, R.E. & Harasewych, 1990:
Catalogue of the Superfamily Cancellarioidea Forbes & Hanley, 1851 (Gastropoda: Prosobranchia). The Nautilus, Supplement 1 (Issued with Volume
103): 69 pp.
Ravn, J.P.J. 1902:
Molluskerne i Danmarks Kridtaflejringer. I. Lamellibranchiater. Det Kongelige Danske Videnskabernes Selskabs Skrifter, 6. Række, naturvidenskabelig og mathematisk Afdeling XI. 4: 70 pp.
Ravn, J.P.J. 1902:
Molluskerne i Danmarks Kridtaflejringer. II Scaphopoder, Gastropoder og Cephalopoder. Det Kongelige Danske Videnskabernes Selskabs Skrifter, 6. Række, naturvidenskabelig og mathematisk Afdeling XI 4: 5-66 pp., pls. 1-5.
Ravn, J.P.J. 1933:
Études sur les Pélécypodes et Gastropodes du Calcaire de Faxe. Det Kongelige Danske Videnskabernes Selskabs Skrifter, naturvidenskabelig og mathematisk
Afdeling, 9. Række, V 2. 1-74.
Schilder, F.A. 1928:
Die Cypraeacea des Daniums von Dänemark und Schonen. Danmarks geologiske Undersøgelse IV. Række 2(3): 27 pp.
Schnetler, K.I., Lozouet, P. & Pacaud, J.- M. 2000:
Revision of the gastropod family Scissurellidae from the Middle Danian (Paleocene) of Denmark. Bulletin of the
Geological Society of Denmark 48: 79-90. Copenhagen.
Schnetler, K.I. 2001:
The Selandian (Paleocene) mollusc fauna from Copenhagen: the Poul Harder 1920 Collection. Geology of Denmark Survey Bulletin 37: 85 pp.
Schnetler,
K.I., & Petit, R.E.
2006:
Revision of the gastropod family Cancellariidae from the Danian (Early Paleocene)
of Fakse, Denmark. – Cainozoic Research
4(1–2), pp.97–108.
A new chiton from Fakse
Sigwart, J., Andersen, S.B., & Schnetler, K.I.
2007:
First record of a chiton from
the Palaeocene of Denmark (Polyplacophora: Leptochitonidae)
and its phylogenetic affinities. – Journal of Systematic Palaeontology 5 (2),
123–132.
