| 1. |
- Ahlberg, Per, et al.
(author)
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Miaolingian (Cambrian) trilobite biostratigraphy and carbon isotope chemostratigraphy in the Tingskullen drill core, Öland, Sweden
- 2021
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In: Estonian Journal of Earth Sciences. - : Estonian Academy Publishers. - 1736-7557 .- 1736-4728. ; 70:1, s. 18-35
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Journal article (peer-reviewed)abstract
- The Cambrian succession of the Tingskullen drill core from northern Öland comprises Cambrian Series 2 and Miaolingian (Wuliuan Stage) siliciclastic strata. The major portion of the succession is represented by the Miaolingian Borgholm Formation, which, in ascending order, is subdivided into the Mossberga, Bårstad and Äleklinta members. The Äleklinta Member is barren of body fossils, whereas the Mossberga and Bårstad members are moderately to highly fossiliferous and biostratigraphically reasonably well constrained. Trilobites and agnostoids from the Bårstad Member are indicative of the Acadoparadoxides pinus Zone.The Mossberga Member has not yielded any zonal guide fossils but is tentatively assigned to the Eccaparadoxides insularis Zone. A δ13Corg curve throughout the Borgholm Formation shows a general positive trend upsection without any distinctive excursion, suggesting that the Wuliuan Acadoparadoxides (Baltoparadoxides) oelandicus Superzone (the ‘Oelandicus beds’) of Öland is younger than the negative Redlichiid–Olenellid Extinction Carbon isotope Excursion (ROECE), which is known from near the top of Stage 4 and close to the traditional ‘Lower–Middle Cambrian boundary’ in several parts of the world.
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| 2. |
- Bergstrom, Jan, et al.
(author)
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Upper lower Cambrian (provisional Cambrian Series 2) trilobites from northwestern Gansu Province, China
- 2014
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In: Estonian Journal of Earth Sciences. - : Estonian Academy Publishers. - 1736-7557 .- 1736-4728. ; 63:3, s. 123-143
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Journal article (peer-reviewed)abstract
- Upper lower Cambrian (provisional Cambrian Series 2) trilobites are described from three sections through the Shuangyingshan Formation in the Beishan area, northwestern Gansu Province, China. The trilobite fauna is dominated by eodiscoid and 'corynexochid' trilobites, together representing at least ten genera: Serrodiscus, Tannudiscus, Calodiscus, Pagetides, Kootenia, Edelsteinaspis, Ptarmiganoides?, Politinella, Dinesus and Subeia. Eleven species are described, of which seven are identified with previously described taxa and four described under open nomenclature. The composition of the fauna suggests biogeographic affinity with Siberian rather than Gondwanan trilobite faunas, and the Cambrian Series 2 faunas described herein and from elsewhere in northwestern China seem to be indicative of the marginal areas of the Siberian palaeocontinent. This suggests that the Middle Tianshan-Beishan Terrane may have been located fairly close to Siberia during middle-late Cambrian Epoch 2.
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| 3. |
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| 4. |
- Fadel, Alexandre, et al.
(author)
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Palaeoenvironmental signatures revealed from rare earth element (REE) compositions of vertebrate microremains of the Vesiku Bone Bed (Homerian, Wenlock), Saaremaa Island, Estonia
- 2015
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In: Estonian journal of earth sciences. - : Estonian Academy Publishers. - 1736-4728 .- 1736-7557. ; 64:1, s. 36-41
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Journal article (peer-reviewed)abstract
- Rare earth elements (REEs) have been analysed from fossil vertebrate microremains (thelodont scales) from the Vesiku Bone Bed, Saaremaa, Estonia, using in situ microsampling by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Well-preserved scales of three species of the genus Thelodus (T. carinatus, T. laevis and Thelodus sp.) show very uniform REE patterns with slightly lower overall REE concentrations in enameloid than in dentine, with enrichment in middle REEs, depletion in heavy REEs and pronounced negative europium anomaly, but no cerium anomaly. The results of this study suggest a similar diagenetic history and possibly contemporaneous habitats for all three Thelodus species, as well as possible suboxic to anoxic conditions of the bottom and pore waters during the formation of the Vesiku Bone Bed.
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| 5. |
- Fryda, Jiri, et al.
(author)
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First record of the early Sheinwoodian carbon isotope excursion (ESCIE) from the Barrandian area of northwestern peri-Gondwana
- 2015
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In: Estonian Journal of Earth Sciences. - : Estonian Academy Publishers. - 1736-7557 .- 1736-4728. ; 64:1, s. 42-46
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Journal article (peer-reviewed)abstract
- The delta C-13 record from an early Sheinwoodian limestone unit in the Prague Basin suggests its deposition during the time of the early Sheinwoodian carbon isotope excursion (ESCIE). The geochemical data set represents the first evidence for the ESCIE in the Prague Basin which was located in high latitudes on the northwestern peri-Gondwana shelf during early Silurian times.
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| 6. |
- Gubanov, Alexander P., et al.
(author)
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A new record of the enigmatic mollusc Jinonicella from the Silurian of the Carnic Alps, Austria
- 2018
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In: Estonian journal of earth sciences. - : ESTONIAN ACADEMY PUBLISHERS. - 1736-4728 .- 1736-7557. ; 67:2, s. 158-164
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Journal article (peer-reviewed)abstract
- 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.
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| 7. |
- Histon, Kathleen, et al.
(author)
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Preface
- 2015
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In: Estonian journal of earth sciences. - 1736-4728 .- 1736-7557. ; 64:1, s. 1-2
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Journal article (other academic/artistic)abstract
- Evolutionary palaeoecology and palaeobiogeography: year 4 of the IGCP-591 project 'The Early to Middle Palaeozoic Revolution - Bridging the Gap between the Great Ordovician Biodiversification Event and the Devonian Terrestrial Revolution
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| 8. |
- Holmer, Lars E., 1960-, et al.
(author)
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The Early Devonian (Emsian) acrotretid microbrachiopod Opsiconidion minor Popov, 1981, from the Alaska/Yukon Territory border and Novaya Zemlya
- 2020
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In: Estonian journal of earth sciences. - : Estonian Academy Publishers. - 1736-4728 .- 1736-7557. ; 69:3, s. 143-153
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Journal article (peer-reviewed)abstract
- New records of the poorly known acrotretid (Biernatidae) microbrachiopod Opsiconidion minor Popov are described from middle Emsian strata of the Ogilvie Formation in eastcentral Alaska and the adjacent Yukon Territory, Canada, and compared with new betterpreserved topotypes from the late Early Devonian (Emsian) of Novaya Zemlya, Russia. In Alaska O. minor occurs together with fragmentary material of Lingulipora sp. and an indeterminate discinid. The only other previous record of O. minor, outside the type area, comes from the Early to ?Middle Devonian (Pragian to ?Givetian) of Australia (Victoria and NSW). Opsiconidion Ludvigsen is a stratigraphically extremely longranging and cosmopolitan acrotretid, which exhibits a remarkable conservatism; the morphology of the ventral valve remains essentially unchanged from the earliest Ordovician (Darriwilian) records to the Devonian.
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| 9. |
- Holmer, Lars E., 1960-, et al.
(author)
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The problematic lingulate brachiopod Aulonotreta from the Ordovician (Dapingian-Darriwilian) of Baltoscandia
- 2019
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In: Estonian journal of earth sciences. - : Estonian Academy Publishers. - 1736-4728 .- 1736-7557. ; 68:4, s. 206-224
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Journal article (peer-reviewed)abstract
- The enigmatic and aberrant lingulate brachiopod Aulonotreta antiquissima (Eichwald) from the Dapingian (Volkhov Stage) Toila Formation of northern Estonia and St Petersburg area (Historical Region of Ingria, Ingermanland, or Inkerinmaa; English, Swedish, Finnish) is re-described together with the new species, Aulonotreta neptuni, from the lower Darriwilian (Kunda Stage, lower Valastean Substage) Holen Limestone on the Island of Öland, southern Sweden. The genus is presently endemic to Baltoscandia. The new well-preserved material of Aulonotreta permits an account of the musculature, micro-ornamentation and siphonotretoid-like and non-baculate shell structure, all of which were previously poorly understood. The aberrant morphology and musculature of Aulonotreta suggest that it was adapted to an entirely epifaunal and most likely ambitopic adult mode of life.
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| 10. |
- Kroger, Bjorn, et al.
(author)
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The early Katian (Late Ordovician) reefs near Saku, northern Estonia and the age of the Saku Member, Vasalemma Formation
- 2014
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In: Estonian Journal of Earth Sciences. - : Estonian Academy Publishers. - 1736-7557 .- 1736-4728. ; 63:4, s. 271-276
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Journal article (peer-reviewed)abstract
- Reefs developed simultaneously during the latest Sandbian/earliest Katian global Guttenberg Isotopic Carbon Excursion (GICE) in several places across Baltoscandia. Latest Sandbian/earliest Katian patch reefs are also described from the Vasalemma Formation of northern Estonia. The Saku Member of the Vasalemma Formation was previously considered as a proximal facies related to the reefs. However, the Saku Member clearly post-dates the GICE interval and ranges from the latest Keila to Rakvere in terms of regional stages. Some small reefs occur in direct proximity to the stratotype of the Saku Member. New delta C-13 data from the stratotype section and the adjacent reefs indicate that these reefs developed before the deposition of the Saku Member during the GICE interval. The chemostratigraphic data support the hypothesis of a short-time Baltoscandian reef growth event that terminated during the GICE interval.
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