Revision of thelodonts, acanthodians, conodonts, and the depositional environments in the Burgen outlier (Ludlow, Silurian) of Gotland, SwedenShow others and affiliations
2021 (English)In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 143, no 2-3, p. 168-189Article in journal (Refereed) Published
Abstract [en]
Ludfordian strata exposed in the Burgen outlier in eastern Gotland, Sweden record a time of initial faunal recovery after a global environmental perturbation manifested in the Ludfordian Carbon Isotope Excursion (LCIE). Vertebrate microfossils in the collection of the late Lennart Jeppsson, hosted at the Swedish Museum of Natural History, hold the key to reconstruct the dynamics of faunal immigration and diversification during the decline of the LCIE, but the stratigraphic relationships of the strata have been debated. Historically, they had been placed in the Burgsvik Formation, which included the Burgsvik Sandstone and the Burgsvik Oolite members. We revise the fauna in the Jeppsson collection and characterize key outcrops of Burgen and Kapellet. The former Burgsvik Oolite Member is here revised as the Burgen Oolite Formation. In the Burgenoutlier, back-shoal facies of this formation are represented and their position in the Ozarkodina snajdri Biozone is supported. The shallow-marine position compared to the coeval strata in southern Gotland isreflected in the higher δ13C carb values, reaching +9.2‰. The back-shoal succession includes high-diversity metazoan reefs, which indicate a complete recovery of the carbonate producers as the LCIE declined. The impoverishment of conodonts associated with the LCIE in southern Gotland might be a product of facies preferences, as the diverse environments in the outlier yielded all 21 species known from the formation. Fish diversity also returned to normal levels as the LCIE declined, with a minimum of nine species. In line with previous reports, thelodont scales appear to dominate samples from the Burgen outlier.
Place, publisher, year, edition, pages
London: Taylor & Francis, 2021. Vol. 143, no 2-3, p. 168-189
Keywords [en]
Acanthodians, biostratigraphy, Burgsvik Formation, Ludlow, thelodonts, Lau event, carbon isotope excursion, extinction, recovery, palynology
National Category
Other Earth and Related Environmental Sciences
Research subject
Diversity of life; The changing Earth
Identifiers
URN: urn:nbn:se:nrm:diva-4449DOI: 10.1080/11035897.2021.1907441OAI: oai:DiVA.org:nrm-4449DiVA, id: diva2:1618000
Funder
German Research Foundation (DFG), Ja 2718/1-1Helge Ax:son Johnsons stiftelse , SE-TAF -5040Swedish Research Council, 2019-40612021-12-012021-12-082021-12-09Bibliographically approved