“Hypoxic” Silurian oceans suggest early animals thrived in a low-O2 world
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
“Hypoxic” Silurian oceans suggest early animals thrived in a low-O2 world. / Haxen, Emma R.; Schovsbo, Niels H.; Nielsen, Arne T.; Richoz, Sylvain; Loydell, David K.; Posth, Nicole R.; Canfield, Donald E.; Hammarlund, Emma U.
I: Earth and Planetary Science Letters, Bind 622, 118416, 2023.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - “Hypoxic” Silurian oceans suggest early animals thrived in a low-O2 world
AU - Haxen, Emma R.
AU - Schovsbo, Niels H.
AU - Nielsen, Arne T.
AU - Richoz, Sylvain
AU - Loydell, David K.
AU - Posth, Nicole R.
AU - Canfield, Donald E.
AU - Hammarlund, Emma U.
N1 - Funding Information: Funding: This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No 949538 ). NRP was supported by the Villum Fonden (grant 15397 ), DEC was supported by a research grant ( VIL16518 ) from Villum Fonden . Publisher Copyright: © 2023 The Author(s)
PY - 2023
Y1 - 2023
N2 - Atmospheric oxygen (O2) concentrations likely remained below modern levels until the Silurian–Devonian, as indicated by several recent studies. Yet, the background redox state of early Paleozoic oceans remains poorly constrained, hampering our understanding of the relationship between early animal evolution and O2. Here, we present a multi-proxy analysis of redox conditions in the Caledonian foreland basin to Baltica from the early to the mid-Silurian. Our results indicate that anoxic to severely hypoxic bottom waters dominated during deposition of the Silurian sediments cored in the Sommerodde-1 well (Bornholm, Denmark), and regional comparison suggests that these conditions persisted across the Baltoscandian foreland basin. Indeed, even during times of relative oxygenation, ichnological observations indicate that conditions were, at most, very weakly oxic. The results suggest that dissolved O2 was generally scarce in the bottom waters of the extensive Silurian seaway between Baltica and Avalonia, even between Paleozoic “Anoxic Events”. In light of delayed oxygenation of the atmosphere–hydrosphere system, it may be time to consider that early animals were adapted to “hypoxia” and thrived through ∼100 million years of low-O2 conditions after the Cambrian.
AB - Atmospheric oxygen (O2) concentrations likely remained below modern levels until the Silurian–Devonian, as indicated by several recent studies. Yet, the background redox state of early Paleozoic oceans remains poorly constrained, hampering our understanding of the relationship between early animal evolution and O2. Here, we present a multi-proxy analysis of redox conditions in the Caledonian foreland basin to Baltica from the early to the mid-Silurian. Our results indicate that anoxic to severely hypoxic bottom waters dominated during deposition of the Silurian sediments cored in the Sommerodde-1 well (Bornholm, Denmark), and regional comparison suggests that these conditions persisted across the Baltoscandian foreland basin. Indeed, even during times of relative oxygenation, ichnological observations indicate that conditions were, at most, very weakly oxic. The results suggest that dissolved O2 was generally scarce in the bottom waters of the extensive Silurian seaway between Baltica and Avalonia, even between Paleozoic “Anoxic Events”. In light of delayed oxygenation of the atmosphere–hydrosphere system, it may be time to consider that early animals were adapted to “hypoxia” and thrived through ∼100 million years of low-O2 conditions after the Cambrian.
KW - animal evolution
KW - Baltic basin
KW - caledonian foreland basin
KW - ocean oxygenation
KW - redox
KW - Silurian
U2 - 10.1016/j.epsl.2023.118416
DO - 10.1016/j.epsl.2023.118416
M3 - Journal article
AN - SCOPUS:85173480893
VL - 622
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
SN - 0012-821X
M1 - 118416
ER -
ID: 370492358