Exotic trilobites from the uppermost Cambrian Series 3 and lower Furongian of Sweden

Authors

  • Anna Żylińska Faculty of Geology, University of Warsaw, Żwirki i Wigury 93, PL-02-089 Warszawa
  • Thomas Weidner Ravnholtvej 23, Rårup, 7130 Juelsminde
  • John Ahlgren Backlyckevägen 4B, SE-533 94, Hällekis
  • Per Ahlberg Department of Geology, GeoBiosphere Science Centre, Lund University, Sölvegatan 12, SE-223 62 Lund

Keywords:

Trilobita, Cambrian Series 3, Furongian, Alum Shale, Glacial erratic boulders, Sweden, Denmark, Scandinavia, Exotic trilobites

Abstract

Seventeen taxa of exotic trilobites representing eight families are described from the olenid- and agnostoid-dominated strata of the uppermost Cambrian Series 3 and lower Furongian alum shale facies of Sweden and from glacial erratic boulders of Denmark. Only five taxa are assigned to species level, i.e., Maladioidella abdita (Salter, 1866), Olentella rara (Westergård, 1922), Pedinocephalus peregrinus (Henningsmoen, 1957), Ptychoparia pusilla (Westergård, 1922), and Westergaardella olenorum (Westergård, 1922), whereas the others are left under open nomenclature or remain unrecognized. Most are described for the first time from the Cambrian of Scandinavia. Their affinities point to a strong connection with East Gondwana, Laurentia, Kazakhstania and Siberia. Exotic trilobites appear in the succession directly after periods of very low oxygen concentration in the Alum Shale Sea; their occurrences correspond to the ranges of agnostoid arthropods in the succession and seem to be linked to global transgressive events causing an influx of cool and/or oxygen-depleted waters onto the shelf of the Baltica palaeocontinent.

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Published

2015-02-10

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Articles