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Mats Eriksson

Mats Eriksson


Mats Eriksson

Ordovician and Silurian polychaete diversity and biogeography


  • Mats Eriksson
  • Olle Hints
  • Hannelore Paxton
  • Petra Tonarova

Summary, in English

Eunicidan polychaetes formed a significant part of Early Palaeozoic marine invertebrate communities, as shown by the abundance and diversity of scolecodonts (polychaete jaws) in the fossil record. In this study we summarize the early radiation and biodiversity trends and discuss the palaeobiogeography of these fossils. The oldest (latest Cambrian-Early Ordovician) representatives had primitive, usually symmetrical, placognath/ctenognath type jaw apparatuses. The first more advanced taxa, possessing labidognath-type jaw apparatuses or placognath apparatuses with compound maxillae, are first recorded in the Middle Ordovician. The most significant increase in generic diversity occurred in the Darriwilian, when many common taxa appeared and diversified. The Ordovician and Silurian scolecodont occurrences allow some palaeobiogeographical units and distribution patterns to be explored and outlined. The most robust data presently at hand derive from successions in Baltica and Laurentia. That information, together with new records from other palaeocontinents, reveals a wide distribution for the most frequent and species-rich genera and families, similar to the biogeographical patterns of extant polychaetes. Like many other benthic and pelagic fossil groups, scolecodont-bearing polychaetes show an increased cosmopolitan character in the Silurian as compared with the Ordovician. Species-level endemism appears to be relatively common, inferring a potential for scolecodonts as biogeographical tools in the future.


  • Lithosphere and Biosphere Science

Publishing year







Early Palaezoic Biogeography and Palaeogeography



Document type

Conference paper


Geological Society of London


  • Geology

Conference name

Meeting of IGCP 503 on Ordovician Palaeogeography and Palaeoclimate, 2013

Conference date

2013-08-31 - 2013-09-01

Conference place

Copenhagen, Denmark




  • ISSN: 0435-4052