The Late Jurassic Slottsmøya Member Lagersta¨ tte on Spitsbergen offers a unique opportunity to study the relationships between vertebrate fossil preservation, invertebrate occurrences and depositional environment. In this study, 21... more
The Late Jurassic Slottsmøya Member Lagersta¨ tte 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.
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The Late Jurassic Slottsmøya Member Lagerstätte on Spitsbergen preserves a diverse array of marine reptiles, including four named taxa of ophthalmosaurid ichthyosaurs. One of these, Palvennia hoybergeti, is based on the single holotype... more
The Late Jurassic Slottsmøya Member Lagerstätte on Spitsbergen preserves a diverse array of marine reptiles, including four named taxa of ophthalmosaurid ichthyosaurs. One of these, Palvennia hoybergeti, is based on the single holotype specimen (SVB 1451) with an incomplete skull. A newly discovered specimen (PMO 222.669) with a disarticulated but largely complete skull and anterior postcranium is described, which considerably expands our knowledge of this taxon. Two additional new ophthalmosaurid specimens with pectoral girdles from the same member are described. The taxonomic utility of the ophthalmosaurid pectoral girdle is contentious, and an assessment of seven pectoral girdles from the Slottsmøya Member provides a basis for addressing this question via a 2D landmark principal component analysis of baracromian coracoids. The analysis reveals a taxonomic signal in the coracoids but also highlights the degree of individual variation. Commonly used phylogenetic characters do not f...
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ABSTRACT—Colymbosaurus is a genus of long-necked plesiosaurian represented by two valid species: C. megadeirus from the Upper Kimmeridge Clay Formation (Kimmeridgian–Tithonian) of the United Kingdom and C. svalbardensis from the... more
ABSTRACT—Colymbosaurus is a genus of long-necked plesiosaurian represented by two valid species: C. megadeirus from
the Upper Kimmeridge Clay Formation (Kimmeridgian–Tithonian) of the United Kingdom and C. svalbardensis from the
Slottsmøya Member of the Agardhfjellet Formation (Tithonian–Berriasian) of Svalbard, Norway. Due to the lack of
complete and articulated skeletons and a near absence of cranial material, Colymbosaurus has been problematic to
characterize morphologically. Here, we describe and conduct a phylogenetic analysis on an informative new specimen
referable to C. svalbardensis from the Slottsmøya Member, preserving a large portion of the axial and appendicular skeleton.
The new material contributes important new osteological data for the species and together with an extensive examination of
congeners in British museums, clarifies the diagnostic characters of the genus. We provide two new diagnostic characters of
the epipodials for the genus and reevaluate the utility of an anteroposteriorly oriented bisecting ridge on the distal end of the
propodials. We also present two new diagnostic features for C. svalbardensis regarding the neural canal and femoral
morphology. A phylogenetic analysis recovers a monophyletic and well-supported Colymbosaurus. The new specimen of C.
svalbardensis confirms that this species is not synonymous with other described Slottsmøya Member plesiosauroids, demonstrating considerable diversity of the clade at high latitudes close to the Jurassic–Cretaceous boundary.
the Upper Kimmeridge Clay Formation (Kimmeridgian–Tithonian) of the United Kingdom and C. svalbardensis from the
Slottsmøya Member of the Agardhfjellet Formation (Tithonian–Berriasian) of Svalbard, Norway. Due to the lack of
complete and articulated skeletons and a near absence of cranial material, Colymbosaurus has been problematic to
characterize morphologically. Here, we describe and conduct a phylogenetic analysis on an informative new specimen
referable to C. svalbardensis from the Slottsmøya Member, preserving a large portion of the axial and appendicular skeleton.
The new material contributes important new osteological data for the species and together with an extensive examination of
congeners in British museums, clarifies the diagnostic characters of the genus. We provide two new diagnostic characters of
the epipodials for the genus and reevaluate the utility of an anteroposteriorly oriented bisecting ridge on the distal end of the
propodials. We also present two new diagnostic features for C. svalbardensis regarding the neural canal and femoral
morphology. A phylogenetic analysis recovers a monophyletic and well-supported Colymbosaurus. The new specimen of C.
svalbardensis confirms that this species is not synonymous with other described Slottsmøya Member plesiosauroids, demonstrating considerable diversity of the clade at high latitudes close to the Jurassic–Cretaceous boundary.
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The palaeontology of the Lower to Middle Triassic succession in Spitsbergen has been studied for more than a century and a half. Our ability to properly interpret the evolutionary and ecological implications of the faunas requires precise... more
The palaeontology of the Lower to Middle Triassic succession in Spitsbergen has been studied for more than a century and a half. Our ability to properly interpret the evolutionary and ecological implications of the faunas requires precise stratigraphic control that has only recently become available. Within such a detailed stratigraphic framework, the Spitsbergen fossil material promises to contribute to our understanding of the faunal recovery after the end-Permian mass extinction.