Aubrey Jane Roberts

• Roberts, Aubrey Jane; Etches, Steve; Horton, Nicholas; Marshall, John E. A.; Harding, Ian & Rankin, Kathryn [Show all 7 contributors for this article] (2025). Description of new Kimmerosaurus langhami (Cryptoclididae, Plesiosauria) material recovered from the Kimmeridge Clay Formation, Dorset, U.K. Journal of Vertebrate Paleontology. ISSN 0272-4634. 45(1). doi: 10.1080/02724634.2025.2505520. Full text in Research Archive Show summary

  A new specimen of the cryptoclidid plesiosauroid Kimmerosaurus langhami (EC K2134) is described from the Upper Jurassic Kimmeridge Clay Formation, Kimmeridge Bay, Dorset, U.K. We provide new insights into the cranial morphology of this taxon, and significantly, we report the discovery of the first cryptoclidid hyoid, a useful comparative element for future studies. Comprehensive investigations into the anatomy and paleobiology of Kimmerosaurus langhami have been hampered by the scarcity of relevant fossil material. The previous cranial reconstruction of Kimmerosaurus was based on incomplete skull material consisting of part of the skull roof, brain case, dentary, teeth, and vertebrae. Using computed tomography (CT) scanning, we provide high-resolution 3D images of the new material, adding the rostrum, palate, and revised tooth count to the reconstruction. In addition, this new material provides significant insights into the cranial and anterior cervical morphology of K. langhami. Phylogenetic results support the referral of the specimen, placing EC K2134 in a polytomy with the North American taxon Tatenectes laramiensis and known material of K. langhami. This study highlights the use of computed tomography for description of Kimmeridge Clay fossil material.

• Saugen, Synnøve Mo; Roberts, Aubrey Jane; Engelschiøn, Victoria Sjøholt & Hurum, Jørn Harald (2025). A new assemblage of Lower Triassic neoselachians (Chondrichthyes) from the Grippia Bonebed of Spitsbergen, Norway. Journal of Vertebrate Paleontology. ISSN 0272-4634. 44(3). doi: 10.1080/02724634.2024.2426544. Full text in Research Archive Show summary

  This study reports the rich occurrence of a varied chondrichthyan assemblage from the Lower Triassic of Spitsbergen based on multiple well-preserved isolated teeth. Based on distinct tooth morphology and histology, two species of the genus Synechodus are described: Synechodus incrementum and a new species cf. Synechodus rotheliusi. The new species is diagnosed based on a smooth crown surface with a sharp cutting edge and lingually inclined cusps with acute apices, where the central cusp is considerably higher than the lateral cusplets. Another group of Synechodus teeth has ornamentation where the crests form longitudinal lines at the base of the mesio-distally elongated crown and is identified as S. incrementum. In addition, two new monotypic genera, Eorapax serrasis and Wimanodon marmieri, are described from the same bonebed. Eorapax serrasis has unique morphological features, such as a monocuspid crown with a serrated cutting edge. Whereas W. marmieri is distinguished based on unique apomorphic features such as a round bulgy crown that overhangs the crown-root junction—especially at the crown shoulder. Tooth histology, including enameloid microstructures, is described for the first time and shows that these taxa are distinctly different from other known comparable genera.

• Scharling, Thomas Holm; Roberts, Aubrey Jane; Foffa, Davide; Engelschiøn, Victoria Sjøholt & Hurum, Jørn Harald (2025). Dental and Dietary Disparity Among Marine Vertebrates from the Early Triassic (Spathian) of Svalbard – Life Bites the Dust, or A New Hope? Norwegian Journal of Geology. ISSN 2387-5844. 105. doi: 10.17850/njg105-1-4. Full text in Research Archive Show summary

  The Early Triassic saw the recovery of ecosystems after the most severe mass extinction event in Earth’s history. However, the ecosystems of the Early Triassic and their patterns of recovery after the Permian-Triassic mass extinction are poorly known due to a scarce fossil record. This study uses dental material to provide information on the taxonomic diversity and dietary strategies of marine micro- and macro-vertebrates from the late Early Triassic (Spathian) Grippia bonebed, Spitsbergen, Svalbard. We compiled a collection of over 5,000 teeth and additional tooth-bearing bone elements, which we studied under the microscope and used for systematic interpretations, classification into morphotypes and a qualitative assessment of dental disparity of this assemblage. Multivariate analysis was done on a representative sample of 198 teeth to subdivide the teeth into different morphotypes. The results were used to inform occupied feeding guilds. Nine tooth morphotypes were defined and found to represent a diverse fauna of actinopterygians, marine temnospondyls and marine reptiles. The marine vertebrates of the Grippia bonebed can be divided into at least five different feeding guilds based on their tooth shape and dental features. These include soft-prey piercers/graspers, durophagous hard-prey crushers/grinders, relatively large generalist-feeders, and heterodont omnivores. Additionally, marine reptiles appear to have had a well-established and ecologically diverse presence. This diverse assemblage of marine vertebrates and their dietary strategies show that the marine ecosystem of the Boreal Sea was rapidly diversifying and that complex dietary structures were already established just a few million years after the Permian-Triassic mass extinction. This fits with similar patterns observed in Early Triassic marine strata from China and North America.

• Roberts, Aubrey J.; Rucinski, Maciej Roman; Kear, Benjamin P.; Hammer, Øyvind; Engelschiøn, Victoria Sjøholt & Scharling, Thomas Holm [Show all 8 contributors for this article] (2025). Earliest oceanic tetrapod ecosystem reveals rapid complexification of Triassic marine communities. Science. ISSN 0036-8075. 390(6774), p. 727–727. doi: 10.1126/science.adx7390. Full text in Research Archive Show summary

  Tetrapods invaded oceanic environments after the cataclysmic end-Permian mass extinction (EPME), with temnospondyl amphibian to reptile-dominated assemblages succeeding across the Early Triassic [~251.9 to 247.2 million years ago (Ma)]. However, conflicting fossil occurrences, divergence estimates, and stratigraphic time averaging make the tempo of this landmark evolutionary transition uncertain. In this work, we describe an oceanic tetrapod ecosystem from a condensed mid–Early Triassic (early Spathian, ~249 Ma) bone bed on the arctic island of Spitsbergen. Apex predator ichthyosaurians, small-bodied ichthyopterygians, durophagous ichthyosauriforms, semiaquatic archosauromorphs, euryhaline temnospondyls, coelacanths, lungfish, ray-finned fish, and sharks formed an unexpectedly complex trophic network. Comparative diversity analyses further show that heterogeneous marine vertebrate communities were well established by the late-earliest Triassic (Dienerian-Smithian, ~251 Ma) and integrated fully variegate tetrapod niches by ~3 million years after the EPME.

• Sachs, Sven; Madzia, Daniel; Marx, Miguel; Roberts, Aubrey Jane; Hampe, Oliver & Kear, Benjamin P. (2025). The osteology, taxonomy, and phylogenetic placement of Seeleyosaurus guilelmiimperatoris (Plesiosauroidea, Microcleididae) from the Lower Jurassic Posidonia Shale of Germany. The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology. ISSN 1932-8486. doi: 10.1002/ar.25620. Full text in Research Archive
• Seon, Nicolas; Vincent, Peggy; Delsett, Lene Liebe; Poulallion, Eve; Suan, Guillaume & Lécuyer, Christophe [Show all 10 contributors for this article] (2025). Reassessment of body temperature and thermoregulation strategies in Mesozoic marine reptiles. Paleobiology. ISSN 0094-8373. 51(2), p. 323–343. doi: 10.1017/pab.2025.2. Full text in Research Archive Show summary

  Ichthyosauria, Plesiosauria, and Metriorhynchidae were apex predators in Mesozoic oceanic trophic networks. Previous stable oxygen isotope studies suggested that several taxa belonging to these groups were endothermic and that some of them were homeothermic organisms. However, these conclusions remain contentious owing to the associated uncertainties regarding the δ18O value and oxygen isotope fractionation relative to environmental seawater. Here, we present new bioapatite phosphate δ18O values (δ18Op) of Ichthyosauria, Plesiosauria, and Metriorhynchidae (Middle Jurassic to Early Cretaceous) recovered from mid- to high paleolatitudes to better constrain their thermophysiology and investigate the presence of regional heterothermies. The intraskeletal δ18Op variability failed to reveal distinct heterothermic patterns within any of the specimens, indicating either intrabody temperature homogeneity or an overriding diagenetic overprint of the original biological δ18Op bone record. Body temperature estimates have been reassessed from new and published δ18Op values of well-preserved isolated teeth, recently revised Mesozoic latitudinal δ18O oceanic gradients, and 18O-enrichment factors of fully aquatic air-breathing vertebrates. Our results confirm that Ichthyosauria were homeothermic endotherms (31°C to 41°C), while Plesiosauria were likely poikilothermic endotherms (27°C to 34°C). The new body temperature estimates of the Metriorhynchidae (25°C to 32°C) closely follow ambient temperatures and point to poikilothermic strategy with no or little endothermic ability. These results improve our understanding of Mesozoic marine reptile thermoregulation and indicate that due to their limited body temperature variations, the δ18Op values from Ichthyosauria fossil remains could be used as valuable archives of Mesozoic oceans δ18Osw values that may help improve paleoenvironmental and paleoclimatic reconstructions.

• Kear, Benjamin P.; Roberts, Aubrey Jane; Young, George; Terezow, Marianna; Mantle, Daniel J. & Barros, Isaias Santos [Show all 7 contributors for this article] (2024). Oldest southern sauropterygian reveals early marine reptile globalization. Current Biology. ISSN 0960-9822. 34(12), p. R562–R563. doi: 10.1016/j.cub.2024.03.035. Full text in Research Archive Show summary

  Sauropterygians were the stratigraphically longest-ranging clade of Mesozoic marine reptiles with a global fossil record spanning ∼180 million years1. However, their early evolution has only been known from what is now the Northern Hemisphere, extending across the northern and trans-equatorial western margins of the Tethys paleo-ocean1 after the late-Early Triassic (late Olenekian, ∼248.8 million years [Ma] ago2), and via possible trans-Arctic migration1 to the Eastern Panthalassa super-ocean prior to the earliest Middle Triassic (Olenekian–earliest Anisian3,4, ∼247 Ma). Here, we describe the geologically oldest sea-going reptile from the Southern Hemisphere — a nothosaur (basal sauropterygian5) from the Middle Triassic (Anisian, after ∼246 Ma6) of New Zealand. Time-scaled ancestral range estimations thus reveal an unexpected circum-Gondwanan high-paleolatitude (>60° S7) dispersal from a northern Tethyan origination center. This coincides with the adaptive diversification of sauropterygians after the end-Permian mass extinction8 and suggests that rapid globalization accompanied their initial radiation in the earliest Mesozoic.

• Kear, Benjamin P.; Engelschiøn, Victoria Sjøholt; Hammer, Øyvind; Roberts, Aubrey Jane & Hurum, Jørn Harald (2023). Earliest Triassic ichthyosaur fossils push back oceanic reptile origins. Current Biology. ISSN 0960-9822. 33(5), p. R178–R179. doi: 10.1016/j.cub.2022.12.053. Full text in Research Archive
• Engelschiøn, Victoria Sjøholt; Roberts, Aubrey Jane; With, Ruben & Hammer, Øyvind (2023). Exceptional X-Ray contrast: Radiography imaging of a Middle Triassic mixosaurid from Svalbard. PLOS ONE. 18(5), p. e0285939–e0285939. doi: 10.1371/journal.pone.0285939. Full text in Research Archive
• Roberts, Aubrey Jane; Engelschiøn, Victoria Sjøholt & Hurum, Jørn Harald (2022). First three-dimensional skull of the Middle Triassic mixosaurid ichthyosaur Phalarodon fraasi from Svalbard, Norway. Acta Palaeontologica Polonica. ISSN 0567-7920. 67(1), p. 51–62. doi: 10.4202/app.00915.2021. Full text in Research Archive Show summary

  The marine Middle Triassic sediments of Svalbard are rich in fossiliferous material and are particularly well-known for marine reptile fossils. Here, we present a new specimen of the small-bodied mixosaurid ichthyosaur Phalarodon fraasi from the Botneheia Formation. PMO 235.393 is unusual in being the first three-dimensional mixosaurid skull recovered from this formation, allowing us to use computed tomography to reconstruct the obscured right side of the cranium, resulting in the first 3D model available for a mixosaurid ichthyosaur. Although separated into different slabs, the specimen preserves most of the dermatocranium as well as some partial post-cranial elements. In particular, the rostrum, external naris, dentition, quadrate and sclerotic ring are well-preserved. This methodology gave new insights into the adaptations this taxon has to durophagy, as well as a detailed look at the heterodont dentition present in PMO 235.393. After comparing with other Phalarodon specimens, it was clear that the maxillary heterodonty of this genus is a synapomorphy. As such this was added as a new character in our phylogenetic analysis, supporting the separation of Phalarodon and Mixosaurus.

• Roberts, Aubrey Jane; Druckenmiller, Patrick; Cordonnier, Benoit; Delsett, Lene Liebe & Hurum, Jørn Harald (2020). A new plesiosaurian from the Jurassic–Cretaceous transitional interval of the Slottsmøya Member (Volgian), with insights into the cranial anatomy of cryptoclidids using computed tomography. PeerJ. doi: 10.7717/peerj.8652. Full text in Research Archive Show summary

  Cryptoclidids are a major clade of plesiosauromorph plesiosaurians best known from the Middle—Late Jurassic, but little is known regarding their turnover into the Early Cretaceous. Of the known cryptoclidid genera, most preserve only a limited amount of cranial material and of these Cryptoclidus eurymerus , displays the most complete, but compressed cranium. Thus, the lack of knowledge of the cranial anatomy of this group may hinder the understanding of phylogenetic interrelationships, which are currently predominantly based on postcranial data. Here we present a nearly complete adult cryptoclidid specimen (PMO 224.248) representing a new genus and species Ophthalmothule cryostea gen et sp. nov., from the latest Jurassic to earliest Cretaceous part of the Slottsmøya Member, of central Spitsbergen. The holotype material preserves a complete cranium, partial mandible, complete and articulated cervical, pectoral and anterior to middle dorsal series, along with the pectoral girdle and anterior humeri. High resolution microcomputed tomography reveals new data on the cranial anatomy of this cryptoclidid, including new internal features of the braincase and palate that are observed in other cryptoclidids. A phylogenetic analysis incorporating new characters reveals a novel tree topology for Cryptoclididae and particularly within the subfamily Colymbosaurinae. These results show that at least two cryptoclidid lineages were present in the Boreal Region during the latest Jurassic at middle to high latitudes.

• Delsett, Lene Liebe; Druckenmiller, Patrick Scott; Hammer, Øyvind; Hryniewicz, Krzysztof; Knutsen, Espen Madsen & Koevoets, Maayke Jacqueline [Show all 9 contributors for this article] (2019). Mesozoic marine reptiles from Spitsbergen and their ecosystems. Geology Today. ISSN 0266-6979. 35(1), p. 20–25. doi: 10.1111/gto.12256. Full text in Research Archive Show summary

  In the Mesozoic seas, the apex predators were reptiles. From the Arctic archipelago of Svalbard, the Spitsbergen Mesozoic Research Group has excavated numerous well preserved marine reptile skeletons in order to understand the biology of these animals and the environment they lived in. The work of eleven field seasons has made this one of the largest and most productive palaeontological research projects in the high Arctic world‐wide. The initial eight seasons focused on one of the richest occurrences of Late Jurassic—earliest Cretaceous (c. 150–139 Ma) marine reptiles in the world, and nearly sixty specimens have been collected, together with a diverse assemblage of invertebrates, some of which are associated with methane seeps. The last three seasons were spent investigating events further back in time, as Spitsbergen preserves the remains from some of the first marine reptile radiations in the wake of the most devastating extinction in the history of the Earth, at the Permian–Triassic boundary (c. 252 Ma).

• Delsett, Lene Liebe; Roberts, Aubrey Jane; Druckenmiller, Patrick Scott & Hurum, Jørn Harald (2019). Osteology and phylogeny of Late Jurassic ichthyosaurs from the Slottsmøya Member Lagerstätte (Spitsbergen, Svalbard). Acta Palaeontologica Polonica. ISSN 0567-7920. 64(4), p. 717–743. doi: 10.4202/app.00571.2018. Full text in Research Archive Show summary

  Phylogenetic relationships within the important ichthyosaur family Ophthalmosauridae are not well established, and more specimens and characters, especially from the postcranial skeleton, are needed. Three ophthalmosaurid specimens from the Tithonian (Late Jurassic) of the Slottsmøya Member Lagerstätte on Spitsbergen, Svalbard, are described. Two of the specimens are new and are referred to Keilhauia sp. and Ophthalmosauridae indet. respectively, whereas the third specimen consists of previously undescribed basicranial elements from the holotype of Cryopterygius kristiansenae. The species was recently synonymized with the Russian Undorosaurus gorodischensis, but despite many similarities, we conclude that there are too many differences, for example in the shape of the stapedial head and the proximal head of the humerus; and too little overlap between specimens, to warrant synonymy on species level. A phylogenetic analysis of Ophthalmosauridae is conducted, including all Slottsmøya Member specimens and new characters. The two proposed ophthalmosaurid clades, Ophthalmosaurinae and Platypterygiinae, are retrieved under some circumstances, but with little support. The synonymy of three taxa from the Slottsmøya Member Lagerstätte with Arthropterygius is not supported by the present evidence.

• Roberts, Aubrey Jane; Funke, May-Liss Knudsen; Engelschiøn, Victoria Sjøholt & Hurum, Jørn Harald (2019). The excavation of high arctic, Late Jurassic - Early Cretaceous marine reptiles and their virtual and manual preparation. Geological curator. ISSN 0144-5294. 11, p. 69–79. Full text in Research Archive
• Ekeheien, Christina Pokrie; Delsett, Lene Liebe; Roberts, Aubrey Jane & Hurum, Jørn Harald (2018). Preliminary report on ichthyopterygian elements from the Early Triassic (Spathian) of Spitsbergen. Norwegian Journal of Geology. ISSN 2387-5844. 98(2), p. 219–238. doi: 10.17850/njg98-2-07. Full text in Research Archive Show summary

  Jaw elements of Omphalosaurus sp. are described from the Early Triassic (Spathian) of Marmierfjellet, Spitsbergen. The elements are from the Grippia and the Lower Saurian niveaus in the Vendomdalen Member of the Vikinghøgda Formation. In the Grippia niveau a bonebed was excavated in 2014–15 and a large number of ichthyopterygian elements were recovered. Together with the omphalosaurian jaw elements a collection of large vertebral centra were recognized as different from the smaller Grippia centra and more than 200 large vertebral centra are referred to Ichthyopterygia indet. and tentatively assigned to regions of the vertebral column. We refrain from further assignment due to the systematic position and the difficulty of defining criteria for recognizing postcranial elements of Omphalosaurus.

• Hurum, Jørn Harald; Engelschiøn, Victoria Sjøholt; Økland, Inghild Halvorsen; Bratvold, Janne; Ekeheien, Christina Pokrie & Roberts, Aubrey Jane [Show all 12 contributors for this article] (2018). The history of exploration and stratigraphy of the Early to Middle Triassic vertebrate-bearing strata of Svalbard (Sassendalen Group, Spitsbergen). Norwegian Journal of Geology. ISSN 2387-5844. 98(2), p. 165–174. doi: 10.17850/njg98-2-04. Full text in Research Archive Show summary

  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.

• Økland, Inghild Halvorsen; Delsett, Lene Liebe; Roberts, Aubrey Jane & Hurum, Jørn Harald (2018). A Phalarodon fraasi (Ichthyosauria: Mixosauridae) from the Middle Triassic of Svalbard. Norwegian Journal of Geology. ISSN 2387-5844. 98(2), p. 267–288. doi: 10.17850/njg98-2-06. Full text in Research Archive Show summary

  A new specimen of Phalarodon from the Middle Triassic Botneheia Formation on Svalbard, although not complete, is well preserved with both cranial and postcranial elements. Uncompressed preservation of the rostrum reveals the dental groove divided by alveolar bone between the teeth. The right opisthotic has a thin and plate-like paroccipital process, a structure which has only been observed in Mixosaurus cornalianus among mixosaurids. The rare preservation of the atlas-axis complex, being nearly complete and articulated, is very similar to that of Phalarodon callawayi. The interclavicle, although not complete, is preserved with detailed structures which have previously not been described in Mixosauridae. Contrary to earlier studies, the shoulder girdle, with an articulated scapula and coracoid, reveals a coracoid facet on the scapula. Using comparative morphological and phylogenetic analyses, similarities between the new specimen and the known species of Mixosauridae are addressed. We assign the new specimen to Phalarodon fraasi. With its uncompressed preservation, the new specimen contributes to the knowledge of our morphology of the species. This study suggests a reassignment of the specimen PMO 219.250 to the genus Mixosaurus, and opens up for the possibility of Mixosaurus on Svalbard. This would imply a wider geographical distribution of the genus than previously recognised. Additionally, it would prove the coexistence of Mixosaurus and Phalarodon in a shared habitat at the same point in time, a hypothesis that is strengthened by the differences in dentition which reflects separate feeding habits, and thus different niches.

• Engelschiøn, Victoria Sjøholt; Delsett, Lene Liebe; Roberts, Aubrey Jane & Hurum, Jørn Harald (2018). Large-sized ichthyosaurs from the Lower Saurian niveau of the Vikinghøgda Formation (Early Triassic), Marmierfjellet, Spitsbergen. Norwegian Journal of Geology. ISSN 2387-5844. 98(2), p. 239–266. doi: 10.17850/njg98-2-05. Full text in Research Archive Show summary

  Humeri of Pessopteryx nisseri and vertebrae referred to Cymbospondylus sp. are described from the Lower Saurian niveau at Marmierfjellet, Spitsbergen. This is the most well-preserved Cymbospondylus material described from the Early Triassic so far, and the first description of new material of Pessopteryx nisseri since the species was established. The taxa are not represented by articulated or overlapping material. Herein, the most diagnostic material of both taxa is described and discussed, and the possibility that there is only one large-sized taxon present is suggested. Several specimens of Ichthyosauria indet. are also described. Comparisons are made to previously described specimens from the Lower Saurian niveau, including the disputed Merriamosaurus hulkei. The Boreal Ocean of Svalbard is of particular interest due to its position at the northern margin of Pangea, between the Early Triassic localities of today’s British Colombia and Nevada, and South China. More than 2000 three-dimensional and disarticulated fragments show that large-sized ichthyosaurs had evolved and were numerous by the Early Triassic. This is the first time since the collections of Carl Wiman that the Lower Saurian niveau has been systematically sampled and placed in the modern stratigraphy.

• Delsett, Lene Liebe; Druckenmiller, Patrick Scott; Roberts, Aubrey Jane & Hurum, Jørn Harald (2018). A new specimen of Palvennia hoybergeti: implications for cranial and pectoral girdle anatomy in ophthalmosaurid ichthyosaurs. PeerJ. p. 1–57. doi: 10.7717/peerj.5776. Full text in Research Archive Show summary

  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 fully encapsulate the degree of variation seen in coracoids and in some cases combine analogous features.

• Delsett, Lene Liebe; Roberts, Aubrey Jane; Druckenmiller, Patrick Scott & Hurum, Jørn Harald (2017). A new ophthalmosaurid (ichthyosauria) from Svalbard, Norway, and evolution of the ichthyopterygian pelvic girdle. PLOS ONE. 12:e0169971(1), p. 1–39. doi: 10.1371/journal.pone.0169971. Full text in Research Archive Show summary

  In spite of a fossil record spanning over 150 million years, pelvic girdle evolution in Ichthyopterygia is poorly known. Here, we examine pelvic girdle size relationships using quantitative methods and new ophthalmosaurid material from the Slottsmøya Member Lagerstätte of Svalbard, Norway. One of these new specimens, which preserves the most complete ichthyosaur pelvic girdle from the Cretaceous, is described herein as a new taxon, Keilhauia nui gen. et sp. nov. It represents the most complete Berriasian ichthyosaur known and the youngest yet described from the Slottsmøya Member. It is diagnosed on the basis of two autapomorphies from the pelvic girdle, including an ilium that is anteroposteriorly expanded at its dorsal end and an ischiopubis that is shorter or subequal in length to the femur, as well as a unique character combination. The Slottsmøya Member Lagerstätte ichthyosaurs are significant in that they represent a diverse assemblage of ophthalmosaurids that existed immediately preceding and across the Jurassic–Cretaceous boundary. They also exhibit considerable variation in pelvic girdle morphology, and expand the known range in size variation of pelvic girdle elements in the clade.

• Roberts, Aubrey Jane; Druckenmiller, Patrick S.; Delsett, Lene Liebe & Hurum, Jørn Harald (2017). Osteology and relationships of Colymbosaurus Seeley, 1874, based on new material of C. svalbardensis from the Slottsm?ya Member, Agardhfjellet Formation of central Spitsbergen. Journal of Vertebrate Paleontology. ISSN 0272-4634. 37(1). doi: 10.1080/02724634.2017.1278381. Full text in Research Archive Show summary

  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.

• Hurum, Jørn Harald; Roberts, Aubrey Jane; Dyke, Gareth J.; Grundvåg, Sten-Andreas; Nakrem, Hans Arne & Midtkandal, Ivar [Show all 8 contributors for this article] (2016). Bird or maniraptoran dinosaur? A femur from the Albian strata of Spitsbergen. Palaeontologia Polonica. ISSN 0078-8562. 67, p. 137–147. doi: 10.4202/pp.2016.67_137. Full text in Research Archive
• Delsett, Lene Liebe; Novis, Linn Kristin; Roberts, Aubrey Jane; Koevoets, Maayke Jacqueline; Hammer, Øyvind & Druckenmiller, Patrick Scott [Show all 7 contributors for this article] (2015). The Slottsmøya marine reptile Lagerstätte: depositional environments, taphonomy and diagenesis. Geological Society Special Publication. ISSN 0305-8719. doi: 10.1144/SP434.2. Full text in Research Archive Show summary

  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.

• Hurum, Jørn Harald; Roberts, Aubrey Jane; Nakrem, Hans Arne; Stenløkk, Jan A. & Mørk, Atle (2014). The first recovered ichthyosaur from the Middle Triassic of Edgeoya, Svalbard. Norwegian Petroleum Directorate Bulletin. ISSN 0808-1409. p. 97–110. Full text in Research Archive
• Roberts, Aubrey Jane; Druckenmiller, Patrick Scott; Sætre, Glenn-Peter & Hurum, Jørn Harald (2014). A new upper jurassic ophthalmosaurid ichthyosaur from the Slottsmøya Member, Agardhfjellet Formation of central Spitsbergen. PLOS ONE. 9(8). doi: 10.1371/journal.pone.0103152. Full text in Research Archive Show summary

  Abundant new ichthyosaur material has recently been documented in the Slottsmøya Member of the Agardhfjellet Formation from the Svalbard archipelago of Norway. Here we describe a partial skeleton of a new taxon, Janusaurus lundi, that includes much of the skull and representative portions of the postcranium. The new taxon is diagnosed by a suite of cranial character states including a very gracile stapedial shaft, the presence of a dorsal process on the prearticular and autapomorphic postcranial features such as the presence of an interclavicular trough and a conspicuous anterodorsal process of the ilium. The peculiar morphology of the ilia indicates a previously unrecognized degree of morphological variation in the pelvic girdle of ophthalmosaurids. We also present a large species level phylogenetic analysis of ophthalmosaurids including new and undescribed ichthyosaur material from the Upper Jurassic of Svalbard. Our results recover all Svalbard taxa in a single unresolved polytomy nested within Ophthalmosaurinae, which considerably increases the taxonomic composition of this clade. The paleobiogeographical implications of this result suggest the presence of a single clade of Boreal ophthalmosaurid ichthyosaurs that existed during the latest Jurassic, a pattern also reflected in the high degree of endemicity among some Boreal invertebrates, particularly ammonoids. Recent and ongoing descriptions of marine reptiles from the Slottsmøya Member Lagerstätte provide important new data to test hypotheses of marine amniote faunal turnover at the Jurassic-Cretaceous boundary. This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

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• Jemterud, Torkild; Roberts, Aubrey Jane; Sandve, Geir Kjetil Ferkingstad & Vestre, Katharina (2026). Hva er greia med hestesko? - Abels tårn - NRK Radio. [Radio]. NRK. Full text in Research Archive Show summary

  Når vet en stamcelle hva den skal bli? Hvordan belønne KI? Er jeg mer av min mormor enn av min mor? Hadde dinosaurene pandemier? Hvor fargeblinde er hunder?

• Roberts, Aubrey Jane; Erlien, Wenche; Sørborg, Øystein; Hammer, Øyvind & Hurum, Jørn (2025). Bringing paleontology into the classroom: a digital teaching unit on evolution using ongoing research. Full text in Research Archive
• Hurum, Jørn; Roberts, Aubrey Jane; Hammer, Øyvind; Sørborg, Øystein & Erlien, Wenche (2025). Fossils and evolution - the viten.no program. doi: https:/www.viten.no/filarkiv/evolution/#%2F. Full text in Research Archive
• Hurum, Jørn; Hammer, Øyvind; Roberts, Aubrey Jane & Rucinski, Maciej Roman (2025). Dinosaurene lever! doi: https:/www.verdenskulestedag.no/. Full text in Research Archive
• Hurum, Jørn; Roberts, Aubrey Jane & Sørborg, Øystein (2025). Det nye viten.no programmet. Full text in Research Archive
• Roberts, Aubrey Jane & Hurum, Jørn (2025). Gigantisk samling av fossiler skjulte eldgammel overraskelse. [Internet]. forskning.no. doi: https:/www.forskning.no/dinosaurer-paleontologi-svalbard/se-bildene-gigantisk-norsk-fossil-funn-skjulte-eldgammel-overraskelse/2576299. Full text in Research Archive
• Hurum, Jørn; Roberts, Aubrey Jane & Rucinski, Maciej Roman (2025). The Oldest Sea Where Reptiles Ruled. Now an article in the prestigious journal Science!!! doi: https:/norpal.wordpress.com/2025/11/13/the-oldest-sea-where-reptiles-ruled-now-an-article-in-the-prestigious-journal-science/. Full text in Research Archive
• Hurum, Jørn; Roberts, Aubrey Jane & Rucinski, Maciej Roman (2025). Det eldste havet der reptilene hersket. Nå en artikkel i det prestisjefylte tidsskriftet Science!!! doi: https:/norpal.wordpress.com/2025/11/13/det-eldste-havet-der-reptilene-hersket-na-en-artikkel-i-det-prestisjefylte-tidsskriftet-science/. Full text in Research Archive
• Hurum, Jørn Harald; Roberts, Aubrey Jane; Hammer, Øyvind; Erlien, Wenche & Sørborg, Øystein (2025). fossiler og evolusjon. doi: https:/www.viten.no/filarkiv/evolusjon/#%2F. Full text in Research Archive
• Hurum, Jørn Harald & Roberts, Aubrey Jane (2024). Best practice fieldwork and collections. Full text in Research Archive
• Hurum, Jørn Harald; Nakrem, Hans Arne; Hammer, Øyvind; Roberts, Aubrey Jane; Delsett, Lene Liebe & Engelschiøn, Victoria Sjøholt (2024). 20 years of Arctic excavations and research – Spitsbergen Mesozoic Research Group (SMRG). Full text in Research Archive
• Jemterud, Torkild; Roberts, Aubrey Jane; Görbitz, Carl Henrik & Einevoll, Gaute (2024). Abels tårn. [Radio]. NRK P2. Full text in Research Archive
• Roberts, Aubrey Jane; Aass, Hanne Cecilia & Hurum, Jørn Harald (2024). Dinosaurprat i Abels tårn om Zara og Zelda. [Radio]. Radio NRK P2. Full text in Research Archive
• Roberts, Aubrey Jane (2024). Mesozoic Monsters from the Frozen North. Full text in Research Archive
• Roberts, Aubrey Jane; Etches, Steve; Horton, Nicholas; Stokke, Maren; Marshall, John E. A. & Harding, Ian [Show all 9 contributors for this article] (2024). Two new specimens of Kimmerosaurus expand geographic range and morphological understanding of the genus. Full text in Research Archive
• Roberts, Aubrey Jane; Engelschiøn, Victoria Sjøholt; Kear, Benjamin P. & Hurum, Jørn Harald (2024). Triassic Treasures: New Insights into Svalbard's Marine Reptile Heritage. Full text in Research Archive
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• Nordenhaug, Petter; Engelschiøn, Victoria Sjøholt; Roberts, Aubrey Jane; With, Ruben & Hammer, Øyvind (2024). Deeply rooted — a study of heterodontid mixosaurids from Svalbard using radiography. Full text in Research Archive
• Roberts, Aubrey Jane (2023). Frozen fossils - introduction to my work. Full text in Research Archive
• Roberts, Aubrey Jane; Etches, Steve; Horton, Nicholas; Stokke, Maren; Marshall, John & Harding, Ian [Show all 9 contributors for this article] (2023). Two new Kimmerosaurus specimens expand geographic range and morphological understanding of the genus. Full text in Research Archive
• Roberts, Aubrey Jane (2023). What is a palaeontologist? Full text in Research Archive
• Roberts, Aubrey Jane (2023). Omvisning på Geologisk Museum. Full text in Research Archive
• Bjorå, Charlotte Sletten; Elven, Hallvard; Roberts, Aubrey Jane & Jemterud, Torkild (2023). Sommeravslutning Abels Tårn. [Radio]. NRK P2. Full text in Research Archive
• Roberts, Aubrey Jane; Görbitz, Carl Henrik; Mossige, Joachim; Samset, Bjørn Hallvard & Uggerud, Einar (2023). Abels Tårn. [Radio]. NRK P3 EKKO. Full text in Research Archive
• Roberts, Aubrey Jane; Hurum, Jørn Harald; Kear, Benjamin P. & Foffa, Davide (2023). New archosauriform records from the marine Early Triassic of Svalbard. Full text in Research Archive
• Roberts, Aubrey Jane (2023). Lydene til forhistoriske dyr. [Internet]. ung forskning. Full text in Research Archive
• Roberts, Aubrey Jane (2023). Hvordan jobbe som en dinoforsker. Full text in Research Archive
• Roberts, Aubrey Jane (2023). Morgennytt intervju med NRK om ny NHM dinosaur. [TV]. NRK TV og NRK P3. Full text in Research Archive
• Roberts, Aubrey Jane (2023). Denne havøglen var kongen av havet for 170 millioner år siden. [Internet]. Internett ung forskning. Full text in Research Archive
• Roberts, Aubrey Jane & Simonsen, Vanja (2023). There aint nothing like a sh*t surprise. Full text in Research Archive
• Roberts, Aubrey Jane & Simonsen, Vanja (2023). There aint nothing like a sh*t surprise. Full text in Research Archive
• Roberts, Aubrey Jane (2023). Hva gjør paleontologer på jobb? Paleobloggen. Full text in Research Archive
• Roberts, Aubrey Jane (2022). Hvordan jobber en dinoforsker? Full text in Research Archive
• Roberts, Aubrey Jane (2022). Frozen Fossils. Full text in Research Archive
• Roberts, Aubrey Jane (2022). Hva er en dinosaur? Full text in Research Archive
• Jemterud, Torkild & Roberts, Aubrey Jane (2022). Abels Tårn + ukens makker - Dino spesial. [Radio]. Blindern. Full text in Research Archive
• Seon, Nicolas; Vincent, Peggy; Roberts, Aubrey Jane; Suan, Guillame; Lécuyer, Christophe & Fourel, Francois [Show all 9 contributors for this article] (2022). Intra-skeletal variability in phosphate oxygen isotope composition of marine vertebrates as a tool to track regional heterothermies in mesozoic marine reptiles. Full text in Research Archive
• Engelschiøn, Victoria Sjøholt; Hammer, Øyvind; Hurum, Jørn Harald; Bernhardsen, Sofie; Wesenlund, Fredrik & Roberts, Aubrey Jane [Show all 7 contributors for this article] (2020). Large-scale lateral trends in palaeoenvironment and oxygenation in the Middle Triassic Botneheia Fm. on Svalbard. Full text in Research Archive
• Roberts, Aubrey Jane; Engelschiøn, Victoria Sjøholt; Delsett, Lene Liebe & Hurum, Jørn Harald (2020). The Early Triassic ‘Grippia’ bone bed of Spitsbergen and its implications for taxonomy and palaeobiogeography of vertebrates after the P‐T extinction event. Full text in Research Archive
• Roberts, Aubrey Jane & Krüger, Frida (2020). Monsteret i fjellet. [Internet]. nrk.no/viten. Full text in Research Archive
• Roberts, Aubrey Jane; Russo, Paolo & English, Jan (2020). From Jurassic Oceans to the Wildlife Photographer of the Year. Full text in Research Archive
• Roberts, Aubrey Jane & Rosoman, Beck (2020). A new genus and species of long-neck plesiosaur from the Arctic: Author interview with Aubrey Roberts. [Internet]. PeerJ Community. Full text in Research Archive
• Engelschiøn, Victoria Sjøholt; Bernhardsen, Sofie; Wesenlund, Fredrik; Hurum, Jørn Harald; Hammer, Øyvind & Roberts, Aubrey Jane [Show all 9 contributors for this article] (2019). Mass death by anoxia - or an exceptional preservation interval? The Middle Triassic bivalve beds of Svalbard. Full text in Research Archive
• Maidment, Susannah; Roberts, Aubrey Jane; Dodwell, Lottie & Chapman, Sandra (2019). Jurassic Oceans: Monsters of the Deep. Full text in Research Archive
• Roberts, Aubrey Jane; Delsett, Lene Liebe; Druckenmiller, Patrick Scott; Bratvold, Janne; Ekeheien, Christina & Nash, Victoria Engelschiøn [Show all 7 contributors for this article] (2017). The Early Triassic bone beds of Spitsbergen - marine ecosystem recovery after the P/T extinction event. Full text in Research Archive
• Delsett, Lene Liebe; Roberts, Aubrey Jane; Druckenmiller, Patrick Scott & Hurum, Jørn Harald (2017). Ophthalmosaurid basicranium material from Spitsbergen. Full text in Research Archive
• Delsett, Lene Liebe; Koevoets, Maayke Jacqueline; Hammer, Øyvind; Novis, Linn Kristin; Roberts, Aubrey Jane & Druckenmiller, Patrick Scott [Show all 7 contributors for this article] (2017). Marine reptiles from death to discovery. Full text in Research Archive
• Delsett, Lene Liebe; Koevoets, Maayke Jacqueline; Hammer, Øyvind; Novis, Linn Kristin; Roberts, Aubrey Jane & Druckenmiller, Patrick Scott [Show all 7 contributors for this article] (2017). A model for marine reptile taphonomy in the Late Jurassic Slottsmøya Member Lagerstätte. Full text in Research Archive
• Hurum, Jørn Harald; Økland, Inghild Halvorsen; Ekeheien, Christina; Bratvold, Janne; Nash, Victoria Engelschiøn & Roberts, Aubrey Jane [Show all 14 contributors for this article] (2017). Death and survival in the Early Triassic – Svalbard revisited. Full text in Research Archive
• Vogt, Yngve; Delsett, Lene Liebe; Hurum, Jørn Harald; Roberts, Aubrey Jane; Braathen, Alvar & Bjorå, Charlotte Sletten (2016). Jakten på monsterøglenes forfedre. [Journal]. Aftenposten Historie. Full text in Research Archive
• Roberts, Aubrey Jane; Druckenmiller, Patrick Scott; Delsett, Lene Liebe & Hurum, Jørn Harald (2016). A fresh look at Colymbosaurus (Seeley, 1874), with new information from the Slottsmøya Member, Agardhfjellet Formation, Svalbard. Full text in Research Archive
• Delsett, Lene Liebe; Novis, Linn Kristin; Roberts, Aubrey Jane; Koevoets, Maayke Jacqueline; Hammer, Øyvind & Druckenmiller, Patrick Scott [Show all 7 contributors for this article] (2015). Ichthyosaurs from the Late Jurassic - Early Cretaceous on Spitsbergen. Full text in Research Archive
• Delsett, Lene Liebe; Hurum, Jørn Harald; Bjorå, Charlotte Sletten & Roberts, Aubrey Jane (2015). Graver frem forfedrene til monsterøglene. [Journal]. Apollon. Full text in Research Archive
• Roberts, Aubrey Jane; Druckenmiller, Patrick Scott; Delsett, Lene Liebe & Hurum, Jørn Harald (2015). A fresh look at Colymbosaurus (Owen, 1840) with new nformation from the Slottsmøya Member, Agardhfjellet Formation, Svalbard. Full text in Research Archive
• Hurum, Jørn Harald; Roberts, Aubrey Jane; Nakrem, Hans Arne; Stenløkk, Jan Arne & Mørk, Atle (2015). ODA - The first recovered ichthyosaur from the Middle Triassic of Edgeøya, Svalbard. Full text in Research Archive
• Hurum, Jørn Harald; Roberts, Aubrey Jane; Bjorå, Charlotte Sletten & Delsett, Lene Liebe (2015). Graver fram monsterøglenes forfedre. [Journal]. Plot. Full text in Research Archive
• Roberts, Aubrey Jane; Druckenmiller, Patrick Scott; Delsett, Lene Liebe & Hurum, Jørn Harald (2014). The Slottsmøya Member - A diverse, Upper Jurassic boreal marine reptile Lagerstätte. Full text in Research Archive
• Roberts, Aubrey Jane; Hurum, Jørn Harald & Druckenmiller, Patrick (2013). A new Upper Jurassic ophthalmosaurid ichthyosaur from central Spitsbergen. 61st Symposium on Vertebrate Palaeontology and Comparative Anatomy. Full text in Research Archive
• Hurum, Jørn Harald; Roberts, Aubrey Jane; Nakrem, Hans Arne; Stenløkk, Jan Arne & Mørk, Atle (2013). A first report on a nearly complete Middle Triassic mixosaurid ichthyosaur from Edgeøya, Svalbard archipelago. 61st Symposium on Vertebrate Palaeontology and Comparative Anatomy. Full text in Research Archive
• Roberts, Aubrey Jane; Hurum, Jørn Harald & Sætre, Glenn-Peter (2013). Characterization of a new Ophthalmosaurid ichthyosaur from the Upper Jurassic of Spitsbergen. NGF Abstracts and Proceedings of the Geological Society of Norway. p. 110–110. Full text in Research Archive
• Roberts, Aubrey Jane (2012). Characterization of a new Ophthalmosaurid ichthyosaur from the Upper Jurassic of Spitsbergen. Full text in Research Archive
• Bjorå, Charlotte Sletten; Roberts, Aubrey & Hurum, Jørn Harald (2011). Spitsbergen expedition - blogs on National Geographic News watch. [Internet]. newswatch.nationalgeographic.com. Full text in Research Archive
• Hammer, Øyvind; Hurum, Jørn Harald; Roberts, Aubrey Jane; Engelschiøn, Victoria Sjøholt; Nakrem, Hans Arne & Delsett, Lene Liebe [Show all 8 contributors for this article] (2024). EAVP 2024 Short introduction to the vertebrate paleontology of Svalbard, with excursions to the Triassic and Jurassic. Norsk Geologisk Forening. Full text in Research Archive

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