
Mats Eriksson
Professor

Vagrant benthos (Annelida; Polychaeta) associated with Upper Ordovician carbonate mud-mounds of subsurface Gotland, Sweden.
Author
Summary, in English
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, indicatino that the mud-mounds were formed in such environments.
Department/s
- Lithosphere and Biosphere Science
Publishing year
2009
Language
English
Pages
451-462
Publication/Series
Geological Magazine
Volume
146
Issue
3
Document type
Journal article
Publisher
Cambridge University Press
Topic
- Geology
Keywords
- benthos
- scolecodonts
- polychaete jaws
- mud-mounds
- Upper Ordovician
- Gotland
- Sweden
Status
Published
ISBN/ISSN/Other
- ISSN: 0016-7568