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Vagrant benthos (Annelida; Polychaeta) associated with Upper Ordovician carbonate mud-mounds of subsurface Gotland, Sweden

  • MATS E. ERIKSSON (a1) and OLLE HINTS (a2)


Micropalaeontological investigations of Upper Ordovician carbonate mud-mounds and enclosing strata of subsurface Gotland, Sweden, demonstrate that jaw-bearing polychaetes formed the most diverse faunal element associated with these build-ups. Although not present within the mound cores (intra-mound facies), scolecodonts, or polychaete jaws, occur abundantly immediately below and particularly above the mounds; the supra-mound facies also has the most diverse fossil assemblages. By contrast to the scolecodont distribution, the most diverse conodont faunas were recorded in the intra-mound facies. This reinforces the fact that scolecodont and conodont abundance and diversity numbers are commonly inverse to one another, suggesting that these metazoans occupied different niches and responded differently to taphonomical processes. The polychaete assemblage has no less than 27 species belonging to 12 genera, of which Oenonites, Mochtyella and Pistoprion are the most abundant. The assemblage has a characteristic Baltic signature and is similar in taxonomic composition to coeval ones from other areas of the Baltoscandian palaeobasin, such as that of present-day Estonia. A principal component analysis clusters the Gotland assemblage most closely to those recorded from shallow to transitional shelf environments of Estonia, indicating that the mud-mounds were formed in such environments.


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Barnes, C. R. & Fåræus, L. E. 1975. Provinces, communities, and the proposed nektobenthic habit of Ordovician conodontophorids. Lethaia 8, 133–49.
Bergman, C. 1979. Polychaete jaws. In Lower Wenlock faunal and floral dynamics – Vattenfallet section, Gotland (eds Jaanusson, V., Laufeld, S. & Skoglund, R.), pp. 92–102. Sveriges Geologiska Undersökning C 762.
Bergman, C. F. 1989. Silurian paulinitid polychaetes from Gotland. Fossils and Strata 25, 1128.
Bergström, S. M., Löfgren, A. & Grahn, Y. 2004. The stratigraphy of the Upper Ordovician carbonate mounds in the subsurface of Gotland. GFF 126, 289–96.
Eisenack, A. 1939. Einige neue Annelidenreste aus dem Silur und dem Jura des Baltikums. Zeitschrift für Geschiebeforschung und Flachlandsgeologie 15, 153–76.
Eisenack, A. 1975. Beiträge zur Anneliden-Forschung, I. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 150, 227–52.
Eisenack, A. 1976. Mikrofossilen aus dem Vaginatenkalk von Hälludden, Öland. Palaeontographica Apt. A 154, 181203.
Eriksson, M. 1997. Lower Silurian polychaetaspid polychaetes from Gotland, Sweden. GFF 119, 213–30.
Eriksson, M. 1998. Dubichaetaspis bergmani gen. et sp. n., a facies controlled polychaete from the Silurian of Gotland, Sweden. GFF 120, 21–5.
Eriksson, M. 2001. Silurian ramphoprionid polychaetes from Gotland, Sweden. Journal of Paleontology 75, 9931015.
Eriksson, M. E. 2006. Polychaete jaw apparatuses and scolecodonts from the Ireviken Event interval of Gotland, Sweden. GFF 128, 97101.
Eriksson, M. & Bergman, C. F. 2003. Late Ordovician jawed polychaete faunas of the type Cincinnatian region, U.S.A. Journal of Paleontology 77, 509–23.
Eriksson, M. E., Bergman, C. F. & Jeppsson, L. 2004. Silurian scolecodonts. Review of Palaeobotany and Palynology 131, 269300.
Eriksson, M. E., Leslie, S. A. & Bergman, C. F. 2005. Jawed polychaetes from the upper Sylvan Shale (Upper Ordovician), Oklahoma, USA. Journal of Paleontology 79, 486–96.
Flodén, T., Puura, V., Söderberg, P., Tuuling, I. & Suuroja, K. 1994. The Ordovician–Silurian transition beds in the seafloor between Gotland and Hiiumaa islands, Baltic Proper. Proceedings of the Estonian Academy of Sciences, Geology 43, 117.
Hammer, Ø., Harper, D. A. T. & Ryan, P. D. 2001. PAST: Paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4, 9 pp.
Harris, M. T., Sheehan, P. M., Ainsaar, L., Hints, L., Männik, P., Nõlvak, J. & Rubel, M. 2004. Upper Ordovician sequences of western Estonia. Palaeogeography, Palaeoclimatology, Palaeoecology 210, 135–48.
Hinde, G. J. 1879. On annelid jaws from the Cambro-Silurian, Silurian and Devonian formations in Canada and from the Lower Carboniferous in Scotland. Quarterly Journal of the Geological Society of London 35, 370–89.
Hints, L., Hints, O., Nemliher, R. & Nõlvak, J. 2007. Hulterstad brachiopods and associated faunas in the Vormsi Stage (Upper Ordovician, Katian) of the Lelle core, Central Estonia. Estonian Journal of Earth Sciences 56, 131–42.
Hints, O. 1998. Late Viruan (Caradoc) polychaete jaws from North Estonia and the St. Petersburg region. Acta Palaeontologica Polonica 43, 471516.
Hints, O. 1999. Two new polychaete families from the Upper Ordovician of Estonia. Palaeontology 42, 897906.
Hints, O. 2000. Ordovician eunicid polychaetes of Estonia and surrounding areas: review of their distribution and diversification. Review of Palaeobotany and Palynology 113, 4155.
Hints, O. 2001. Distribution of scolecodonts. In Estonian Geological Sections. Valga (10) drill core (ed. Põldvere, A.), pp. 1214. Tallinn: Geological Survey of Estonia.
Hints, O. & Eriksson, M. E. 2007 a. Diversification and biogeography of scolecodont-bearing polychaetes in the Ordovician. Palaeogeography, Palaeoclimatology, Palaeoecology 245, 95114.
Hints, O. & Eriksson, M. E. 2007 b. Biogeography of Ordovician and Silurian scolecodont-bearing polychaetes. Acta Palaeontologica Sinica 46 (Suppl.), 181–7.
Hints, O., Hints, L., Meidla, T. & Sohar, K. 2003. Biotic effects of the Ordovician Kinnekulle ash-fall recorded in northern Estonia. Bulletin of the Geological Society of Denmark 50, 115–23.
Hints, O., Killing, M., Männik, P. & Nestor, V. 2006. Frequency patterns of chitinozoans, scolecodonts, and conodonts in the upper Llandovery and lower Wenlock of the Paatsalu core, western Estonia. Proceedings of the Estonian Academy of Sciences, Geology 55, 128–55.
Jaanusson, V. 1982. The Siljan District. In Field excursion guide. IV International Symposium on the Ordovician System, Oslo 1982 (eds Bruton, D. L. & Williams, S. H.), pp. 15–29. Palaeontological Contributions of the University of Oslo 279.
Jaanusson, V. 1995. Confacies differentation and upper Middle Ordovician correlation in the Baltoscandian Basin. Proceedings of the Estonian Academy of Sciences, Geology 44, 7386.
Jeppsson, L., Anehus, R. & Fredholm, D. 1999. The optimal acetate buffered acetic acid technique for extracting phosphatic fossils. Journal of Paleontology 73, 964–72.
Jeppsson, L., Fredholm, D. & Mattiasson, B. 1985. Acetic acid and phosphatic fossils – a warning. Journal of Paleontology 59, 952–6.
Kielan-Jaworowska, Z. 1961. On two Ordovician polychaete jaw apparatuses. Acta Palaeontologica Polonica 6, 237–59.
Kielan-Jaworowska, Z. 1962. New Ordovician genera of polychaete jaw apparatuses. Acta Palaeontologica Polonica 7, 291332.
Kielan-Jaworowska, Z. 1966. Polychaete jaw apparatuses from the Ordovician and the Silurian of Poland and a comparison with modern forms. Palaeontologia Polonica 16, 1152.
Kozłowski, R. 1956. Sur quelques appareils masticateurs des Annélides Polychètes ordoviciens. Acta Palaeontologica Polonica 1, 165205.
Krause, F. F., Scotese, C. R., Nieto, C., Sayegh, S. G., Hopkins, J. C. & Meyer, R. O. 2004. Paleozoic stromatactis and zebra carbonate mud-mounds: Global abundance and paleogeographic distribution. Geology 32, 181–4.
Männil, R. M. 1966. Evolution of the Baltic Basin during the Ordovician. Tallinn: Valgus Publishers, 200 pp. (in Russian with English summary).
Mierzejewski, P. 1978. New placognath Eunicida (Polychaeta) from the Ordovician and Silurian of Poland. Acta Geologica Polonica 28, 273–81.
Nestor, H. 1995. Ordovician and Silurian reefs in the Baltic area. Publications of the Service Géolologique de Luxembourg 29, 3947.
Nõlvak, J. 1997. Sedimentary Cover, Ordovician, Introduction. In Geology and Mineral Resources of Estonia (eds Raukas, A. & Teedumäe, A.), pp. 52–5. Tallinn: Estonian Academy Publishers.
Nõlvak, J., Hints, O. & Männik, P. 2006. Ordovician timescale in Estonia: recent developments. Proceedings of the Estonian Academy of Sciences, Geology 55, 95108.
Paxton, H. 2000. Eunicida. In Polychaetes & allies: The southern synthesis. Fauna of Australia. Vol. 4A Polychaeta, Myzostomida, Pogonophora, Echiura, Sipuncula (eds Beesley, P. L., Ross, G. J. B. & Glasby, C. J.), pp. 89104. Melbourne: CSIRO Publishing.
Pratt, B. R. 1982. Stromatolitic framework of carbonate mud-mounds. Journal of Sedimentary Petrology 52, 1203–27.
Sivhed, U., Erlström, M., Bojsen-Koefoed, J. A. & Löfgren, A. 2004. Upper Ordovician carbonate mounds on Gotland, central Baltic Sea: Distribution, composition and reservoir characteristics. Journal of Petroleum Geology 27, 115–40.
Sweet, W. C. & Bergström, S. M. 1984. Conodont provinces and biofacies of the Late Ordovician. Geological Society of America Special Paper 196, 6987.
Szaniawski, H. 1970. Jaw apparatuses of the Ordovician and Silurian polychaetes from the Mielnik borehole. Acta Palaeontologica Polonica 15, 445–72.
Tuuling, I. & Flodén, T. 2000. Late Ordovician carbonate buildups and erosional features northeast of Gotland, northern Baltic Sea. GFF 122, 237–49.
Webby, B. D., Cooper, R. A., Bergström, S. M. & Paris, F. 2004. Stratigraphic Framework and Time Slices. In The Great Ordovician Biodiversification Event (eds Webby, B. D., Paris, F., Droser, M. L. & Percival, I. G.), pp. 41–7. New York: Columbia University Press.
Žebera, K. 1935. Les conodontes et les scolécodontes du Barrandien. Bulletin International de l'Academie des Sciences de Boheme 36, 8896.


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Vagrant benthos (Annelida; Polychaeta) associated with Upper Ordovician carbonate mud-mounds of subsurface Gotland, Sweden

  • MATS E. ERIKSSON (a1) and OLLE HINTS (a2)


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