Conodonts of Laurentian faunal affinities from the Middle Ordovician Svartsætra limestone in the Trondheim Region, Central Norwegian Caledonides.
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- Artikler 
Samples from a 122-meter thick limestone succession at Svartsætra, about 13 km east of Meldal inthe Trondheim Region, west-central Norway, yielded more than 100 conodont elements representing about a dozen multielement species. All are conspecific with, or closely similar to, taxa present in the upper Middle Ordovician of the North American Midcontinent, and a biostratigraphic assessment indicates that the Svartsætra limestone is coeval with the Shermanian Substage of the Chatfieldian Stage in the Uppermost Middle Ordovician of North America. In terms of North American and Atlantic conodont zones, this interval is in the Belodina confluens and lowermost part of the Amorphognatus superbus zones, respectively. The fauna differs strikingly from most other coeval Baltoscandian conodont faunas, the only known exceptions being those of the Mjøsa Limestone in the Oslo Region and the Vasalemma Formation in Estonia which exhibit tha same Laurentian faunal affinities. These units, as well as the Kalstad Limestone of the Meldal area, are interpreted to represent the same brief period of shallow-water, subtropical-tropical, bahamitic limestone deposition with faunas of Laurentian aspect.