| 1. |
- Álvaro, J. Javier, et al.
(författare)
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Global Cambrian trilobite palaeobiogeography assessed using parsimony analysis of endemicity
- 2013
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Ingår i: Early Palaeozoic Biogeography and Palaeogeography. - 0435-4052. - 9781862393738 ; Memoir 38:38, s. 273-296
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Bokkapitel (refereegranskat)abstract
- Palaeobiogeographical data on Cambrian trilobites obtained during the twentieth century are combined in this paper to evaluate palaeoceanographic links through c. 30 myr, once these arthropods biomineralized. Worldwide major tectonostratigraphic units are characterized at series intervals of Cambrian time and datasets of trilobite genera (629 for Cambrian Series 2, 965 for Cambrian Series 3, and 866 for the Furongian Series) are analysed using parsimony analysis of endemicity. Special attention is given to the biogeographical observations made in microcontinents and exotic terranes. The same is done for platform-basinal transects of well-known continental margins. The parsimony analysis of endemicity analysis resulted in distinct palaeogeographical area groupings among the tectonostratigraphic units. With these groupings, several palaeobiogeographical units are distinguished, which do not necessarily fit the previously proposed biogeographical realms and provinces. Their development and spatial distributions are broadly controlled by Cambrian palaeoclimates, palaeogeographical conditions (e.g. carbonate productivity and anoxic conditions) and ocean current circulation.
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| 2. |
- Kouchinsky, Artem, et al.
(författare)
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Early-middle Cambrian stratigraphy and faunas from northern Siberia
- 2022
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Ingår i: Acta Palaeontologica Polonica. - : Institute of Paleobiology, Polish Academy of Sciences. - 0567-7920 .- 1732-2421. ; 67:2, s. 341-464
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Tidskriftsartikel (refereegranskat)abstract
- New assemblages of skeletal fossils chemically extracted from carbonates of the Cambrian Stage 2-Drumian Stage are reported from the lower reaches of the Lena River as well as from the Khorbusuonka, Malaya Kuonamka, and Bol'shaya Kuonamka rivers in northern part of the Siberian Platform. The fauna studied with scanning electron microscopy includes brachiopods, molluscs, hyoliths, halkieriids, chancelloriids, tommotiids, lobopodians, palaeoscolecidans, bradoriids, echinoderms, anabaritids, hyolithelminths, and sponges showing similarity to previously described fossil assemblages from Siberia, Laurentia, and Gondwana. The material includes emended descriptions of Halkieria proboscidea, Hadimopanella knappologica, Archaeopetasus typicus, and first descriptions of Hadimopanella foveata Kouchinsky sp. nov. and Archaeopetasus pachybasalis Kouchinsky sp. nov. Affinity of Archaeopetasus to chancelloriids is suggested. Finding of an in-place operculum in a planispiral shell of Michniakia minuta enables reinterpretation of this form as a hyolith, not a mollusc. The cambroclavids Cambroclavus sp. and Zhijinites clavus and the earliest echinoderms belonging to the Rhombifera and Ctenocystoidea are reported respectively from the lower Botoman stage and Botoman-Toyonian transitional beds, correlated with Cambrian Stage 4. Carbon isotopes are analysed from sections of the Chuskuna (upper Kessyusa Group), Erkeket, Kuonamka, Olenyok, Yunkyulyabit-Yuryakh, Tyuser and Sekten formations. A major part of the delta C-13 record is obtained from the Cambrian Stage 4-Drumian Stage strata which remain incompletely characterised by chemostratigraphy. The Lower Anomocarioides limbataeformis Carbon isotope Excursion (LACE) from the Drumian Stage of the Khorbusuonka River is introduced herein. New chemostratigraphic data are used for regional and global correlation and facilitate study of the evolutionary development of animals and faunas through the "Cambrian explosion".
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| 3. |
- Kouchinsky, Artem, et al.
(författare)
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Lower–Middle Cambrian faunas and stratigraphy from northern Siberia
- 2022
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Ingår i: Acta Palaeontologica Polonica. - Warsaw : Polish Academy of Sciences. - 0567-7920 .- 1732-2421. ; 67, s. 341-464
-
Tidskriftsartikel (refereegranskat)abstract
- New assemblages of skeletal fossils chemically extracted from carbonates of the Cambrian Stage 2–Drumian Stage are reported from the lower reaches of the Lena River as well as from the Khorbusuonka, Malaya Kuonamka, and Bol’shaya Kuonamka rivers in northern part of the Siberian Platform. The fauna studied with scanning electron microscopy includes brachiopods, molluscs, hyoliths, halkieriids, chancelloriids, tommotiids, lobopodians, palaeoscolecidans, bradoriids, echinoderms, anabaritids, hyolithelminths, and sponges showing similarity to previously described fossil assemblages from Siberia, Laurentia, and Gondwana. The material includes emended descriptions of Halkieria proboscidea, Hadimopanella knappologica, Archaeopetasus typicus, and first descriptions of Hadimopanella foveata Kouchinsky sp. nov. and Archaeopetasus pachybasalis Kouchinsky sp. nov. Affinity of Archaeopetasus to chancelloriids is suggested. Finding of an in-place operculum in a planispiral shell of Michniakia minuta enables reinterpretation of this form as a hyolith, not a mollusc. The cambroclavids Cambroclavus sp. and Zhijinites clavus and the earliest echinoderms belonging to the Rhombifera and Ctenocystoidea are reported respectively from the lower Botoman stage and Botoman–Toyonian transitional beds, correlated with Cambrian Stage 4. Carbon isotopes are analysed from sections of the Chuskuna (upper Kessyusa Group), Erkeket, Kuonamka, Olenyok, Yunkyulyabit-Yuryakh, Tyuser and Sekten formations. A major part ofthe δ13C record is obtained from the Cambrian Stage 4–Drumian Stage strata which remain incompletely characterised by chemostratigraphy. The Lower Anomocarioides limbataeformis Carbon isotope Excursion (LACE) from the Drumian Stage of the Khorbusuonka River is introduced herein. New chemostratigraphic data are used for regional and global correlation and facilitate study of the evolutionary development of animals and faunas through the “Cambrian explosion”.
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