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Ornithopod tracksite from Lower Cretaceous of Svalbard (free pdf) + more Scandavian Arctic Mesozoic papers



Ben Creisler
bcreisler@gmail.com

Some recent papers not yet mentioned.

These papers are advance online versions for the following special
publication not yet published:

Geological Society Special Publication SP434:  Mesozoic Biotas of
Scandinavia and its Arctic Territories

Edited by B. P. Kear, J. Lindgren, J. H. Hurum, J. Milàn and V. Vajda

The Mesozoic is arguably the most spectacular interval of biotic
evolution. However, global biodiversity from this time interval is
incompletely documented. Scandinavia and its Arctic territories
represent a hitherto enigmatic geographical region that has recently
yielded many globally significant discoveries and offered new insights
into Mesozoic high-latitude ecosystems and environments.

http://sp.lyellcollection.org/online-first/434

==

Some are available in open access.

===


Jørn H. Hurum, Patrick S. Druckenmiller, Øyvind Hammer, Hans A.
Nakrem, and Snorre Olaussen (2016)
The theropod that wasn't: an ornithopod tracksite from the
Helvetiafjellet Formation (Lower Cretaceous) of Boltodden, Svalbard.
Geological Society Special Publications 434 (advance online publication)
doi:10.1144/SP434.10
http://sp.lyellcollection.org/content/early/2016/01/05/SP434.10.abstract?sid=ee8dc18c-1780-4526-beb9-1d29b1db6204

Free pdf:

http://sp.lyellcollection.org/content/early/2016/01/05/SP434.10.full.pdf+html?sid=ee8dc18c-1780-4526-beb9-1d29b1db6204


We re-examine a Lower Cretaceous dinosaur tracksite at Boltodden in
the Kvalvågen area, on the east coast of Spitsbergen, Svalbard. The
tracks are preserved in the Helvetiafjellet Formation (Barremian). A
sedimentological characterization of the site indicates that the
tracks formed on a beach/margin of a lake or interdistributary bay,
and were preserved by flooding. In addition to the two imprints
already known from the site, we describe at least 34 additional,
previously unrecognized pes and manus prints, including one trackway.
Two pes morphotypes and one manus morphotype are recognized. Given the
range of morphological variation and the presence of manus tracks, we
reinterpret all the prints as being from an ornithopod rather than a
theropod, as previously described. We assign the smaller (morphotype
A, pes; morphotype B, manus) to Caririchnium billsarjeanti. The larger
(morphotype C, pes) track is assigned to Caririchnium sp., differing
in size and interdigital angle from the two described ichnospecies C.
burreyi and C. billsarjeanti. The occurrence of a quadrupedal, small
to medium-sized ornithopod in Svalbard is puzzling, considering the
current palaeogeographical reconstructions and that such dinosaur
tracks have mainly been described from Europe but not North America.
====


Stephen F. Poropat, Elisabeth Einarsson, Johan Lindgren, Mohamad
Bazzi, Clarence Lagerstam, and Benjamin P. Kear (2015) [2016]
Late Cretaceous dinosaurian remains from the Kristianstad Basin of
southern Sweden.
Geological Society Special Publications 434 (advance online publication)
doi: 10.1144/SP434.8
http://sp.lyellcollection.org/content/early/2015/12/14/SP434.8.abstract

Mesozoic dinosaur fossils are exceptionally rare in Scandinavia. The
Swedish record is typically depauperate, with the Kristianstad Basin
of Skåne (Scania) yielding all of the known fossils from Swedish
Cretaceous strata. Although highly fragmentary, these body remnants
are important because they provide evidence of a relatively diverse
fauna, including previously recognized hesperornithiform birds and
leptoceratopsid ceratopsians, as well as indeterminate ornithopods
that are confirmed here for the first time. In this paper, we describe
three phalanges (from Åsen) and an incomplete right tibia (from
Ugnsmunnarna) from the Kristianstad Basin. One of the phalanges
appears to pertain to a leptoceratopsid ceratopsian, providing further
evidence of these small ornithischians in the Cretaceous sediments of
Sweden. The other two phalanges are interpreted as deriving from small
ornithopods similar to Thescelosaurus and Parksosaurus. The tibia
appears to represent the first evidence of a non-avian theropod
dinosaur in the Cretaceous of Sweden, with a previous report of
theropod remains based on fish teeth having been corrected by other
authors. The remains described herein provide important additions to
the enigmatic dinosaurian fauna that inhabited the Fennoscandian
archipelago during the latest Cretaceous.

======

Hendrik Klein, Jesper Milàn, Lars B. Clemmensen, Nicolaj Frobøse,
Octávio Mateus, Nicole Klein, Jan S. Adolfssen, Eliza J. Estrup, and
Oliver Wings
Archosaur footprints (cf. Brachychirotherium) with unusual morphology
from the Upper Triassic Fleming Fjord Formation (Norian–Rhaetian) of
East Greenland.
Geological Society Special Publications 434 (advance online publication)
doi: 10.1144/SP434.1
http://sp.lyellcollection.org/content/early/2015/12/14/SP434.1.abstract


The Ørsted Dal Member of the Upper Triassic Fleming Fjord Formation in
East Greenland is well known for its rich vertebrate fauna,
represented by numerous specimens of both body and ichnofossils. In
particular, the footprints of theropod dinosaurs have been described.
Recently, an international expedition discovered several slabs with
100 small chirotheriid pes and manus imprints (pes length 4–4.5 cm) in
siliciclastic deposits of this unit. They show strong similarities
with Brachychirotherium, a characteristic Upper Triassic ichnogenus
with a global distribution. A peculiar feature in the Fleming Fjord
specimens is the lack of a fifth digit, even in more deeply impressed
imprints. Therefore, the specimens are assigned here tentatively to
cf. Brachychirotherium. Possibly, this characteristic is related to
the extremely small size and early ontogenetic stage of the
trackmaker. The record from Greenland is the first evidence of this
morphotype from the Fleming Fjord Formation. Candidate trackmakers are
crocodylian stem group archosaurs; however, a distinct correlation
with known osteological taxa from this unit is not currently possible.
While the occurrence of sauropodomorph plateosaurs in the bone record
links the Greenland assemblage more closer to that from the Germanic
Basin of central Europe, here the described footprints suggest a
Pangaea-wide exchange.

====

Lene L. Delsett, Linn K. Novis, Aubrey J. Roberts, Maayke J. Koevoets,
Øyvind Hammer, Patrick S. Druckenmiller, and Jørn H. Hurum (2015)
[2016]
The Slottsmøya marine reptile Lagerstätte: depositional environments,
taphonomy and diagenesis.
Geological Society Special Publications 434 (advance online publication)
doi:10.1144/SP434.2
http://sp.lyellcollection.org/content/early/2015/12/17/SP434.2.abstract

Free pdf:

http://sp.lyellcollection.org/content/early/2015/12/17/SP434.2.full.pdf+html


The Late Jurassic Slottsmøya Member Lagerstätte on Spitsbergen offers
a unique opportunity to study the relationships between vertebrate
fossil preservation, invertebrate occurrences and depositional
environment. In this study, 21 plesiosaurian and 17 ichthyosaur
specimens are described with respect to articulation, landing mode,
preservation, and possible predation and scavenging. The stratigraphic
distribution of marine reptiles in the Slottsmøya Member is analysed,
and a correlation between high total organic content, low oxygen
levels, few benthic invertebrates and optimal reptile preservation is
observed. A new model for 3D preservation of vertebrates in highly
compacted organic shales is explained.

====


Sven Sachs, Johan Lindgren, and Mikael Siversson (2015) [2016]
A partial plesiosaurian braincase from the Upper Cretaceous of Sweden.
Geological Society Special Publications 434 (advance online publication)
doi: 10.1144/SP434.7
http://sp.lyellcollection.org/content/early/2015/12/14/SP434.7.abstract

A partial exoccipital–opisthotic from the uppermost lower Campanian
(Upper Cretaceous) of the Åsen locality, Kristianstad Basin,
southernmost Sweden, is described and illustrated. The fossil
represents the first braincase element of a plesiosaur found in
Sweden. It includes the chamber for the ampulla and utriculus,
openings for the caudal vertical and horizontal semicircular canals,
and four foramina for cranial nerves. The incomplete braincase can be
referred to an elasmosaurid plesiosaur, and closely resembles the
exoccipital–opisthotic of Libonectes morgani and a referred specimen
of Aristonectes parvidens. Although we discuss putative postcranial
material of the elasmosaurid subfamily Aristonectinae in the uppermost
lower Campanian of southernmost Sweden, the exoccipital–opisthotic
from Åsen most likely belongs to a juvenile individual of a
non-aristonectine elasmosaur.

===

Benjamin P. Kear, Stephen F. Poropat, and Mohamad Bazzi (2015) [2016]
Late Triassic capitosaurian remains from Svalbard and the
palaeobiogeographical context of Scandinavian Arctic temnospondyls.
Geological Society Special Publications 434 (advance online publication)
doi: 10.1144/SP434.11
http://sp.lyellcollection.org/content/early/2015/12/16/SP434.11.abstract?sid=ee8dc18c-1780-4526-beb9-1d29b1db6204


The Norwegian Arctic Svalbard archipelago is famous for its prolific
record of Early–Middle Triassic vertebrate fossils. These represent
mainly marine amniotes, together with sharks, bony fishes and
temnospondyl amphibians, the latter providing an important faunal
correlate with coeval assemblages from the Danish autonomous region of
Greenland. However, substantial biostratigraphical gaps exist in the
Upper Triassic strata of Svalbard, which are marked by pronounced
facies shifts from marine to deltaic systems and intermittent
depositional hiatuses. These are accompanied by a dearth of documented
vertebrate remains, a notable exception being the partial skull of the
capitosaurian Capitosaurus polaris and a few isolated stereospondylian
intercentra probably from the middle–late Carnian De Geerdalen
Formation of Spitsbergen. Reassessment of this material, which
incorporates the only undisputed capitosaurian fossil from Svalbard,
indicates affinity with Cyclotosaurus, known elsewhere from the late
Norian–early Rhaetian Fleming Fjord Formation of Greenland. The
Scandinavian Arctic temnospondyls constituted components of sympatric
assemblages that inhabited the Boreal margin of Pangaea throughout the
Triassic.
==



Lars B. Clemmensen, Jesper Milàn, Jan Schulz Adolfssen, Eliza Jarl
Estrup, Nicolai Frobøse, Nicole Klein, Octávio Mateus, and Oliver
Wings (2015) [2016]
The vertebrate-bearing Late Triassic Fleming Fjord Formation of
central East Greenland revisited: stratigraphy, palaeoclimate and new
palaeontological data.
Geological Society Special Publications 434 (advance online publication)
doi: 10.1144/SP434.3
http://sp.lyellcollection.org/content/early/2015/12/14/SP434.3.abstract


In Late Triassic (Norian–Rhaetian) times, the Jameson Land Basin lay
at 40° N on the northern part of the supercontinent Pangaea. This
position placed the basin in a transition zone between the relatively
dry interior of the supercontinent and its more humid periphery.
Sedimentation in the Jameson Land Basin took place in a lake–mudflat
system and was controlled by orbitally forced variations in
precipitation. Vertebrate fossils have consistently been found in
these lake deposits (Fleming Fjord Formation), and include fishes,
dinosaurs, amphibians, turtles, aetosaurs and pterosaurs. Furthermore,
the fauna includes mammaliaform teeth and skeletal material. New
vertebrate fossils were found during a joint vertebrate
palaeontological and sedimentological expedition to Jameson Land in
2012. These new finds include phytosaurs, a second stem testudinatan
specimen and new material of sauropodomorph dinosaurs, including
osteologically immature individuals. Phytosaurs are a group of
predators common in the Late Triassic, but previously unreported from
Greenland. The finding includes well-preserved partial skeletons that
show the occurrence of four individuals of three size classes. The new
finds support a late Norian–early Rhaetian age for the Fleming Fjord
Formation, and add new information on the palaeogeographical and
palaeolatitudinal distribution of Late Triassic faunal provinces.

==


S. McLoughlin and C. Strullu-Derrien (2015) [2016]
Biota and palaeoenvironment of a high middle-latitude Late Triassic
peat-forming ecosystem from Hopen, Svalbard archipelago.
Geological Society Special Publications 434 (advance online publication)
doi: 10.1144/SP434.4
http://sp.lyellcollection.org/content/early/2015/12/22/SP434.4.abstract

Free pdf:

http://sp.lyellcollection.org/content/early/2015/12/22/SP434.4.full.pdf+html

A siliceous permineralized peat block recovered from Hopen in the
Svalbard archipelago hosts a low-diversity Late Triassic flora
dominated by autochthonous roots and stems of bennettitaleans and
lycophytes, and parautochthonous leaves, sporangia, spores and pollen
from a small range of pteridophytes and gymnosperms. Some
parenchymatous bennettitalean root cells show interactions with
chytrid fungi and bacteria; the remains of other fungi and fungi-like
organisms are dispersed within the peat's detrital matrix. Cavities
excavated through some roots and compacted detritus contain abundant
coprolites probably derived from sapro-xylophagous oribatid mites,
although no body fossils have yet been identified. Sparse larger
coprolites containing leaf fragments attest to the presence of
invertebrate folivores in the ancient ecosystem. The low-diversity
flora, relatively few trophic levels and simple nutritional web,
together with sedimentological aspects of the host formation and the
peat structure, collectively favour accumulation of the organic mass
as a fibric (root-dominated) peat within a temperate (high
middle-latitude), well-aerated mire.