Journal cover Journal topic
Fossil Record A palaeontological open-access journal of the Museum für Naturkunde
Journal topic

Journal metrics

Journal metrics

  • IF value: 0.783 IF 0.783
  • IF 5-year value: 1.000 IF 5-year
    1.000
  • CiteScore value: 0.86 CiteScore
    0.86
  • SNIP value: 0.543 SNIP 0.543
  • SJR value: 0.382 SJR 0.382
  • IPP value: 0.72 IPP 0.72
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 12 Scimago H
    index 12
Volume 14, issue 1
Foss. Rec., 14, 35-53, 2011
https://doi.org/10.1002/mmng.201000014
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.
Foss. Rec., 14, 35-53, 2011
https://doi.org/10.1002/mmng.201000014
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.

  01 Feb 2011

01 Feb 2011

Mass concentration of Hirnantian cephalopods from the Siljan District, Sweden; taxonomy, palaeoecology and palaeobiogeographic relationships

B. Kröger1,*, J. O. R. Ebbestad2, A. E. S. Högström3, and Å. M. Frisk4 B. Kröger et al.
  • 1Museum für Naturkunde Berlin, Invalidenstraße 43, 10115 Berlin, Germany
  • 2Museum of Evolution, Uppsala University, Norbyvägen 16, 752 36 Uppsala, Sweden
  • 3Tromsø University Museum, Naharat Sciences, 9037 Tromsø, Norway
  • 4Department of Earth Sciences, Palaeobiology, Villavägen 16, 752 36 Uppsala, Sweden
  • *Museum für Naturkunde Berlin, Invalidenstraße 43, 10115 Berlin, Germany

Abstract. The Hirnantian Glisstjärn Formation (Normalograptus persculptus graptolite Biozone) is a succession of limestones and shales onlapping the Katian Boda Limestone in the Siljan District, Sweden. It contains a conspicuous, up to several decimeter thick bed densely packed with bipolarly oriented, orthoconic cephalopod conchs that can reach lengths of more than 120 cm. Conch fragmentation, bioereosion and the generally poor preservation of the conchs indicate time averaging and the conchs are tentatively interpreted as beached, and a result of winnowing. Ten nautiloid species were collected from the Glisstjärn Formation of which five are new: Dawsonoceras gregarium n. sp., Discoceras siljanense n. sp., Isorthoceras dalecarlense n. sp., Retizitteloceras rarum gen. et sp. n., and Transorthoceras osmundsbergense gen. et sp. n. The non-endemic taxa in most cases are known from elsewhere in Baltoscandia, except one species which is known from Siberia, and North America respectively. Proteocerid orthoceridans dominate the association, of which T. osmundsbergense is the predominant species. Oncocerids are diverse but together with tarphycerids very rare. Notable is the lack of many higher taxa, that are typical for other Late Ordovician shallow water depositional settings. Based on the taxonomical composition of the cephalopod mass occurrence it is interpreted as an indicator of eutrophication of the water masses in the area.

doi:10.1002/mmng.201000014

Publications Copernicus
Download
Citation
Share