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Ebbestad, Jan Ove R.ORCID iD iconorcid.org/0000-0001-8769-3572
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Publications (10 of 158) Show all publications
Gubanov, A. P., Ebbestad, J. O., Männik, P. & Bogolepova, O. (2020). New data on the problematic mollusc Jinonicella from the early Silurian of east Siberia. GFF
Open this publication in new window or tab >>New data on the problematic mollusc Jinonicella from the early Silurian of east Siberia
2020 (English)In: GFF, ISSN 1103-5897, E-ISSN 2000-0863Article in journal (Refereed) Epub ahead of print
Abstract [en]

Jinonicella kolebabai Pokorný, 1978, a small problematic “mollusc” of unknown origin is described from the early Silurian (early to mid Llandovery) of east Siberia. This is the first record of Jinonicella from Siberia. Previous Silurian records of Jinonicella were from the late Llandovery (Telychian) of North America and the Wenlock to Ludlow of Europe (Bohemia, Gotland and the Carnic Alps of Austria). Jinonicella shows a wide range of geographic and stratigraphic distribution. It was reported from three palaeocontinents and several smaller terranes. It also demonstrates adaptation to different environments from shallow to deep-water settings, and spans several climatic zones from equatorial to temperate belts. The wide distribution and adaptation to a broad range of environments allow Jinonicella to subsist for about 100 my, i.e., from the Middle Ordovician to the Late Devonian surviving through two major extinction events.

Keywords
Silurian, Siberia, problematic mollusc, palaeogeography
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-403169 (URN)10.1080/11035897.2019.1708451 (DOI)
Available from: 2020-01-24 Created: 2020-01-24 Last updated: 2020-01-24Bibliographically approved
Meinhold, G., Jensen, S., Hoyberget, M., Arslan, A., Ebbestad, J. O., Hogstrom, A. E. S., . . . Taylor, W. L. (2019). First record of carbonates with spherulites and cone-in-cone structures from the Precambrian of Arctic Norway, and their palaeoenvironmental significance. Precambrian Research, 328, 99-110
Open this publication in new window or tab >>First record of carbonates with spherulites and cone-in-cone structures from the Precambrian of Arctic Norway, and their palaeoenvironmental significance
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2019 (English)In: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 328, p. 99-110Article in journal (Refereed) Published
Abstract [en]

We report for the first time carbonates from the upper Ediacaran sedimentary succession of Finnmark, Arctic Norway. Carbonates occur as calcareous siliciclastic beds, lenses, and concretions, some with calcite spherulites and cone-in-cone (CIC) calcite, in a mudrock to fine-grained sandstone succession from approximately 3 m to 26 m above the base of the 2nd cycle of the Manndrapselva Member of the Stahpogieddi Formation (Vestertana Group). They occur c. 40 m below the Ediacaran-Cambrian boundary, which is well defined by trace fossils. Thin-section petrography and scanning micro X-ray fluorescence elemental mapping reveal a layered composition of the calcareous sedimentary rocks. In some of those, well-developed nested cones of CIC calcite form the outer layer. Thin clay coatings outline individual cones. The inner layers are composed of (1) carbonate with calcite spherulites (grainstone) and (2) thinly laminated fine-grained calcareous siliciclastics (mudstone and wackestone) indicated by elevated concentrations of Al, Si, Fe, and Ti. The inner siliciclastic layers contain framboidal pyrite and probably organic matter. Formation of calcite spherulites took place probably at the sediment-water interface either in a coastal littoral environment or in situ in the sublittoral zone under high alkaline conditions whereas CIC calcite formed during burial diagenesis and clearly in pre-Caledonian time before metamorphism and cleavage formation. This new record of carbonates with calcite spherulites and CIC structures from the Ediacaran of Arctic Norway adds to their rare occurrences in the geological record.

Keywords
Carbonates, Calcite spherulites, Cone-in-cone structures, Ediacaran, Norway, Baltica
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-388756 (URN)10.1016/j.precamres.2019.04.014 (DOI)000470941100007 ()
Funder
The Research Council of Norway, 231103
Available from: 2019-08-14 Created: 2019-08-14 Last updated: 2019-08-14Bibliographically approved
Agić, H., Högström, A. E. S., Moczydlowska, M., Jensen, S., Palacios, T., Meinhold, G., . . . Höyberget, M. (2019). Organically-preserved multicellular eukaryote from the early Ediacaran Nyborg Formation, Arctic Norway. Scientific Reports, 9, Article ID 14659.
Open this publication in new window or tab >>Organically-preserved multicellular eukaryote from the early Ediacaran Nyborg Formation, Arctic Norway
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2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 14659Article in journal (Refereed) Published
Abstract [en]

Eukaryotic multicellularity originated in the Mesoproterozoic Era and evolved multiple times since, yet early multicellular fossils are scarce until the terminal Neoproterozoic and often restricted to cases of exceptional preservation. Here we describe unusual organically-preserved fossils from mudrocks, that provide support for the presence of organisms with differentiated cells (potentially an epithelial layer) in the late Neoproterozoic. Cyathinema digermulense gen. et sp. nov. from the Nyborg Formation, Vestertana Group, Digermulen Peninsula in Arctic Norway, is a new carbonaceous organ-taxon which consists of stacked tubes with cup-shaped ends. It represents parts of a larger organism (multicellular eukaryote or a colony), likely with greater preservation potential than its other elements. Arrangement of open-ended tubes invites comparison with cells of an epithelial layer present in a variety of eukaryotic clades. This tissue may have benefitted the organism in: avoiding overgrowth, limiting fouling, reproduction, or water filtration. C. digermulense shares characteristics with extant and fossil groups including red algae and their fossils, demosponge larvae and putative sponge fossils, colonial protists, and nematophytes. Regardless of its precise affinity, C. digermulense was a complex and likely benthic marine eukaryote exhibiting cellular differentiation, and a rare occurrence of early multicellularity outside of Konservat-Lagerstatten.

Place, publisher, year, edition, pages
NATURE PUBLISHING GROUP, 2019
National Category
Other Earth and Related Environmental Sciences Evolutionary Biology
Identifiers
urn:nbn:se:uu:diva-396716 (URN)10.1038/s41598-019-50650-x (DOI)000489556200037 ()31601898 (PubMedID)
Funder
Swedish Research Council, VR2016-06810Swedish Research Council, VR6212012-1669The Research Council of Norway, 231103
Available from: 2019-11-08 Created: 2019-11-08 Last updated: 2019-11-08Bibliographically approved
Høyberget, M., Ebbestad, J. O. & Funke, B. (2019). Re-evaluation of the stratigraphically important olenellid trilobite Holmia cf. mobergi from the Cambrian Series 2, Stage 3 and its implications for the lower Cambrian stratigraphy in the Mjøsa area, Norway. Norwegian Journal of Geology, 99(1), 1-30
Open this publication in new window or tab >>Re-evaluation of the stratigraphically important olenellid trilobite Holmia cf. mobergi from the Cambrian Series 2, Stage 3 and its implications for the lower Cambrian stratigraphy in the Mjøsa area, Norway
2019 (English)In: Norwegian Journal of Geology, Vol. 99, no 1, p. 1-30Article in journal (Refereed) Published
Abstract [en]

The olenellid trilobite Holmia cf. mobergi, known from a single cephalon in the upper lower Cambrian strata from a river section in Flagstadelva, Hamar, has played a significant stratigraphic role in interpreting the lower Cambrian informal Series 2, Stage 3 in the Mjøsa area, Norway, sinceits discovery in the early 1950s. It was considered one of the oldest trilobite taxa in the lower Cambrian of Scandinavia, but the stratigraphic leveland biozonation of the cephalon were problematic and a matter of discussion for decades. Moreover, organic-walled microfossil biostratigraphyquestioned the supposed age of the trilobite. New specimens of this taxon collected from the type locality show that the species occurs at a differentstratigraphic level than first reported, prompting a new description of the species and a re-evaluation of the taxon’s biostratigraphic significance.Holmia cf. mobergi is compared with new and well-preserved topotype material of Holmia inusitata, a very rare taxon hitherto known from onesingle outcrop in an autochthonous setting in Norway. Holmia cf. mobergi and Holmia inusitata are here considered conspecific.

Keywords
Cambrian Series 2, biostratigraphy, Holmia, ontogeny, Mjøsa area, Norway
National Category
Other Earth and Related Environmental Sciences
Research subject
Earth Science with specialization in Historical Geology and Palaeontology
Identifiers
urn:nbn:se:uu:diva-398899 (URN)10.17850/njg99-1-04 (DOI)
Available from: 2019-12-11 Created: 2019-12-11 Last updated: 2019-12-18Bibliographically approved
Fryda, J., Ebbestad, J. O. & Friydova, B. (2019). The oldest members of porcellioidea (gastropoda): A new link between baltica and perunica. PAPERS IN PALAEONTOLOGY, 5(2), 281-297
Open this publication in new window or tab >>The oldest members of porcellioidea (gastropoda): A new link between baltica and perunica
2019 (English)In: PAPERS IN PALAEONTOLOGY, ISSN 2056-2799, Vol. 5, no 2, p. 281-297Article in journal (Refereed) Published
Abstract [en]

The strata of Gotland, Sweden, provide one of the richest records of Silurian gastropod faunas in the world. Recent re-evaluation of museum collections revealed for the first time the presence of gastropods of the superfamily Porcellioidea (Archaeogastropoda) in the Silurian strata of Gotland (Baltica). Additionally, the porcellioideans from Gotland represent the oldest record of the superfamily, members of which were an element of marine gastropod communities from Silurian to Cretaceous time, a period of more than 350 million years. The morphology of the sinistrally coiled teleoconchs in the oldest porcellioidean gastropods supports an existing hypothesis that the pseudo-bilaterally symmetrical teleoconch and the mid-whorl position of the selenizone in the post-Silurian porcelliids is a derived shell character. The occurrence of porcellioidean gastropods in the Silurian strata of Baltica also represents a new faunal link between Baltica and Perunica which corresponds well with published palaeobiogeographical and palaeogeographical models. Six taxa are described, including the Sheinwoodian (early Wenlock) Gotlandiela contraria (Lindstrom), the Gorstian (early Ludlow) Mannegaardina hedei gen. et sp. nov., the Ludfordian (late Ludlow) Gotlandiela sp. and Pernericirrus lindstroemi sp. nov., as well as two agnesiid species.

Keywords
Gastropoda, Porcellioidea, early phylogeny, faunal affinity, Silurian, Baltica
National Category
Other Earth and Related Environmental Sciences
Identifiers
urn:nbn:se:uu:diva-387298 (URN)10.1002/spp2.1241 (DOI)000467885500004 ()
Available from: 2019-06-24 Created: 2019-06-24 Last updated: 2019-06-24Bibliographically approved
Gubanov, A. P., Ebbestad, J. O. & Bogolepova, O. K. (2018). A new record of the enigmatic mollusc Jinonicella from the Silurian of the Carnic Alps, Austria. Estonian journal of earth sciences, 67(2), 158-164
Open this publication in new window or tab >>A new record of the enigmatic mollusc Jinonicella from the Silurian of the Carnic Alps, Austria
2018 (English)In: Estonian journal of earth sciences, ISSN 1736-4728, E-ISSN 1736-7557, Vol. 67, no 2, p. 158-164Article in journal (Refereed) Published
Abstract [en]

The small enigmatic mollusc Jinonicella kolebabai Pokorny, 1978 is described from the upper Silurian Cardiola Formation at the Rauchkofel Sud section of the Carnic Alps, Austria. The associated conodonts suggest a late Ludlow (Ludfordian) Polygnathoides siluricus conodont Zone. Previous Silurian records of Jinonicella are known from the Wenlock to Ludlow of the Czech Republic, USA, Gotland of Sweden and the Carnic Alps of Austria. The wide distribution of this taxon across different climatic zones and widely separated areas in the Silurian is problematic, and it is unclear whether Jinonicella was present in high-latitude areas before the end-Ordovician cooling and mass extinction or was dispersed during the Silurian. Possible planktotrophy in Jinonicella and Silurian ocean circulation patterns may explain the dispersal, but within the framework of current palaeogeographical reconstructions the model does not adequately explain an equatorial to polar distribution of other contemporaneous benthic faunas from these areas.

Place, publisher, year, edition, pages
ESTONIAN ACADEMY PUBLISHERS, 2018
Keywords
Silurian, Carnic Alps, problematic mollusc, Jinonicella, palaeogeography
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-361297 (URN)10.3176/earth.2018.12 (DOI)000439004100005 ()
Available from: 2018-09-26 Created: 2018-09-26 Last updated: 2018-09-26Bibliographically approved
Berg-Madsen, V., Valent, M. & Ebbestad, J. O. (2018). An orthothecid hyolith with a digestive tract from the early Cambrian of Bornholm, Denmark. GFF, 140(1), 25-37
Open this publication in new window or tab >>An orthothecid hyolith with a digestive tract from the early Cambrian of Bornholm, Denmark
2018 (English)In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 140, no 1, p. 25-37Article in journal (Refereed) Published
Abstract [en]

The hyolith assemblage from the early Cambrian of Bornholm, Denmark, shows a higher diversity than contemporary assemblages in Baltoscandia. The most common species in the Green Shales (Laesa Formation, Norretorp Member, Cambrian Stage 3), is Hyolithes [=Hyolithus] (Orthotheca) johnstrupi Holm, 1893. A specimen of this species shows a well-preserved and almost complete digestive tract, folded into an approximately 22mm long chevron-like structure comprised of at least 20 arcuate loops on the ventral side and a flattened, gently sinuous to straight anal tube on the dorsal side. The thin, phosphatic outer shell layer of the conch is crushed under the digestive tract due to compaction while the digestive tract is preserved in three dimensions and appears undisturbed. The shape of the digestive tract is similar to that of the middle Cambrian Guduguwan hardmani (Etheridge) from Australia and the lower Cambrian specimens from Russia described by Mekova & Sysoev. The Danish specimen is probably an adult, lending support to the idea that the orthothecid digestive tract becomes more complex during ontogeny. Hyolithus (Orthotheca) johnstrupi is revised and here referred to Circotheca Sysoev, 1958.

Place, publisher, year, edition, pages
TAYLOR & FRANCIS LTD, 2018
Keywords
Orthotheca johnstrupi revised, digestive tract, early Cambrian, Bornholm, Denmark
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-356329 (URN)10.1080/11035897.2018.1432680 (DOI)000432160200003 ()
Available from: 2018-07-25 Created: 2018-07-25 Last updated: 2018-07-25Bibliographically approved
Weidner, T. & Ebbestad, J. O. (2018). Anopolenus henrici Salter, a middle Cambrian Drumian centropleurid trilobite from the Alum Shale Formation of Scandinavia. Bulletin of the Geological Society of Denmark, 66, 223-228
Open this publication in new window or tab >>Anopolenus henrici Salter, a middle Cambrian Drumian centropleurid trilobite from the Alum Shale Formation of Scandinavia
2018 (English)In: Bulletin of the Geological Society of Denmark, ISSN 0011-6297, E-ISSN 2245-7070, Vol. 66, p. 223-228Article in journal (Refereed) Published
Abstract [en]

Centropleurid trilobites include five genera of which Centropleura Angelin, Anopolenus Salter, Clarella Howell and Luhops Snajdr are known from eight species in the traditional middle Cambrian (Miaolingian Series, Drumian Stage) of Sweden and Denmark (Bornholm). Beishanella Xiang & Zhang has not been recorded in Scandinavia so far, and no centropleurids have been reported from Norway. Of these taxa, only Centropleura is common in Scandinavia. Two pygidia previously identified as Centropleura sp. and Anopolenus sp. from erratics in Germany and Bornholm, respectively, as well as a new pygidum from Scania in Sweden are here identified as Anopolenus henrici Salter. Elsewhere, the species is known from Wales, Avalonian Canada, Siberia, Alaska, and Sardinia, occurring in the A. atavus and P. punctuosus zones (the former in Siberia only). The presence of this species increases the known diversity of Centropleuridae in Scandinavia and is important for correlation between Baltica and Avalonia.

Place, publisher, year, edition, pages
GEOLOGICAL SOC DENMARK, 2018
Keywords
Centropleurid trilobite, Miaolingian, Drumian, Alum Shale Formation, Bornholm, Scania, Scandinavia
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-369435 (URN)000449616600001 ()
Available from: 2018-12-17 Created: 2018-12-17 Last updated: 2019-01-22Bibliographically approved
Meinhold, G., Perschl, M., Schröpfer, M., Steichert, A., Ebbestad, J. O., Högström, A., . . . Taylor, W. L. (2018). Composition and provenance of upper Neoproterozoic and Cambrian sediments from Finnmark, Arctic Norway: Insights from a multi-method approach on the Digermulen Peninsula. In: : . Paper presented at Geobonn 2018, 2-6 September 2018, Bonn, Germany (pp. 96). Hannover
Open this publication in new window or tab >>Composition and provenance of upper Neoproterozoic and Cambrian sediments from Finnmark, Arctic Norway: Insights from a multi-method approach on the Digermulen Peninsula
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2018 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

The remote Digermulen Peninsula by the Tanafjorden of north-eastern Finnmark, Arctic Norway, contains an almost complete sedimentary record across the Ediacaran–Cambrian transition as well as microfossils, macrofossils and trace fossils for studying the Ediacaran biota and the Cambrian radiation. It is one of the few localities worldwide and the only locality in Scandinavia where Ediacara-type fossils have been found. The site was located at the edge of Baltica during the Ediacaran–Cambrian transition, where potentially the dramatic climatic turnover from icehouse to greenhouse conditions can be deduced and tied to large-scale plate tectonics. The Digermulen Peninsula was first studied in the 1930s by Sven Føyn, who also published a geological map in 1937, emended by Harold G. Reading in 1959. In the following years, more detailed mapping was carried out by students from Oxford University. The exposed rocks on the Digermulen Peninsula belong to the Vestertana and Digermulen groups of the Lower Allochthon overlying the Baltic Shield. The succession consists mainly of quartz-rich sandstones and mudrocks. Deposition took place in various environments including fluvial, shallow marine and deeper marine settings. As shown by previous studies using palaeocurrent data, sediment supply was from the Baltic Shield toward the passive margin of Baltica in pre-Ediacaran time. At one point within the Ediacaran succession, it shifted by 180 degrees due to the newly formed Timanian orogen. This orogen formed in north-eastern Baltica during the late Neoproterozoic. It caused a change in source area due to the formation of the Timanian foreland basin to the east of Digermulen Peninsula. Extensive field and laboratory work by the Digermulen Early Life Research Group, with funding from the Research Council of Norway, allows for the first time a detailed analysis of sediment supply and to test current palaeotectonic models based on a multi-method provenance approach on Neoproterozoic and Cambrian mudrocks and sandstones of the Digermulen Peninsula. The methods include, amongst others, thin-section petrography, bulk-rock geochemistry (XRF, ICP-MS), bulk-rock mineralogy (XRD), conventional heavy mineral analysis, single-grain geochemistry (EMP) and zircon U-Pb geochronology. We present and discuss the first results to decipher the sediment sources and to track changes of sediment supply through this critical time interval of Earth’s history.

Place, publisher, year, edition, pages
Hannover: , 2018
Keywords
Digermulen Peninsula Ediacaran, Cambrian, provenance
National Category
Other Earth and Related Environmental Sciences Geology
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-371699 (URN)
Conference
Geobonn 2018, 2-6 September 2018, Bonn, Germany
Available from: 2018-12-27 Created: 2018-12-27 Last updated: 2019-03-13Bibliographically approved
Agic, H., Högström, A., Jensen, S., Ebbestad, J. O., Meinhold, G., Taylor, W. L., . . . Høyberget, M. (2018). Life through the 'Varanger ice ages': microfossil record of late Neoproterozoic glacial-interglacial units from arctic Norway. In: Geological Society of America Abstracts with Programs: . Paper presented at GSA Annual Meeting in Indianapolis, Indiana, USA - 2018. Geological Society of America, 50
Open this publication in new window or tab >>Life through the 'Varanger ice ages': microfossil record of late Neoproterozoic glacial-interglacial units from arctic Norway
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2018 (English)In: Geological Society of America Abstracts with Programs, Geological Society of America, 2018, Vol. 50Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

The late Neoproterozoic strata in Finnmark (Arctic Norway) provide a good sedimentary record of Neoproterozoic glaciations on the Baltica paleocontinent. The lower Vestertana Group exposed on the Digermulen Peninsula contains two glaciogenic units, the Smalfjord and Mortensnes formations. Chemostratigraphic correlation dated the Smalfjord diamictite to the Marinoan glaciation (650-635 Ma), yet its age was also proposed to be older, per correlation to glacial units in central and southern Scandinavia. The diamictites are bracketing shales and siltstones of the interglacial Nyborg Formation. Stratigraphic, paleontological, and sedimentological data are presented from the interglacial-glacial succession, investigated by the Digermulen Early Life Research Group. Palynological analysis yielded well-preserved organic-walled microfossils (OWM) from the Nyborg Fm., and from fine-grained diamictite matrix in the Mortensnes Fm. via a modified extraction method.

The interglacial Nyborg Fm. hosts a moderate diversity assemblage of prokaryotic and eukaryotic OWM, as well as acanthomorphic acritarchs such as Ceratosphaeridium, ?Cavaspina, and a novel process-bearing form. Organically preserved, enigmatic multicellular eukaryotic fossils occur in the upper Nyborg Fm. The Mortensens glacial assemblage is less diverse and contains bacterial filaments, leiosphaerids, toroidal forms, and Micrhystridium-type minute acanthomorphs.

The presence of Doushantuo-Pertatataka type acritarchs in the Nyborg Fm., and small acanthomorphs in the Mortensnes diamictite corroborate an early Ediacaran age for the interglacial-glacial succession on Digermulen. In addition to the trace fossil and body-fossil record of Ediacara-biota in the overlying Stáhpogieddi Formation, the microfossil biostratigraphy suggests Marinoan and Gaskiers glaciation equivalent ages of the Varanger glaciations in Finnmark. Protistan diversity in the succession declined through and following the glaciation, until late Ediacaran.

Place, publisher, year, edition, pages
Geological Society of America, 2018
Series
Geological Society of America Abstracts with Programs, ISSN ISSN 0016-7592 ; 50
Keywords
Organic walled microfossils, Digermulen Peninsula, Neoproterozoic, glaciation
National Category
Other Earth and Related Environmental Sciences
Research subject
Earth Science with specialization in Historical Geology and Palaeontology
Identifiers
urn:nbn:se:uu:diva-371741 (URN)10.1130/abs/2018AM-322291 (DOI)
Conference
GSA Annual Meeting in Indianapolis, Indiana, USA - 2018
Projects
Digermulen Early Life Research
Available from: 2018-12-28 Created: 2018-12-28 Last updated: 2019-03-13Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8769-3572

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