Iterative evolution of digitate planktonic foraminifera
Digitate shell morphologies have evolved repeatedly in planktonic foraminifera throughout the Cretaceous and Cenozoic. Digitate species are usually rare in fossil and modern assemblages but show increased abundance and diversity at times during the Cretaceous and middle Eocene. In this paper we disc...
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The Paleontological Society
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Online Access: | https://orca.cardiff.ac.uk/id/eprint/1371/ https://doi.org/10.1666/06034.1 |
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:1371 2023-05-15T18:00:31+02:00 Iterative evolution of digitate planktonic foraminifera Coxall, Helen Kathrine Wilson, Paul A. Pearson, Paul Nicholas Sexton, Phillip Francis 2007-12-01 https://orca.cardiff.ac.uk/id/eprint/1371/ https://doi.org/10.1666/06034.1 unknown The Paleontological Society Coxall, Helen Kathrine https://orca.cardiff.ac.uk/view/cardiffauthors/A007483I.html, Wilson, Paul A., Pearson, Paul Nicholas https://orca.cardiff.ac.uk/view/cardiffauthors/A0179150.html orcid:0000-0003-4628-9818 orcid:0000-0003-4628-9818 and Sexton, Phillip Francis 2007. Iterative evolution of digitate planktonic foraminifera. Paleobiology 33 (4) , pp. 495-516. 10.1666/06034.1 https://doi.org/10.1666/06034.1 doi:10.1666/06034.1 GC Oceanography QE Geology Article PeerReviewed 2007 ftunivcardiff https://doi.org/10.1666/06034.1 2022-10-20T22:31:56Z Digitate shell morphologies have evolved repeatedly in planktonic foraminifera throughout the Cretaceous and Cenozoic. Digitate species are usually rare in fossil and modern assemblages but show increased abundance and diversity at times during the Cretaceous and middle Eocene. In this paper we discuss the morphology and stratigraphic distribution of digitate planktonic foraminifera and establish the isotopic depth ecology of fossil ones to draw parallels with modern counterparts. δ18O and δ13C values of six extinct and two modern digitate species, from six time slices (Cenomanian, Turonian, Eocene, Miocene, Pleistocene and Holocene) have similar isotopic depth ecologies, consistently registering the most negative δ13C and usually the most positive δ18O compared to coexisting species. These results indicate a similar deep, subthermocline (>150 m) habitat, characterized by lower temperatures, reduced oxygen, and enrichment of dissolved inorganic carbon. This is consistent with water-column plankton studies that provide insight into the depth preferences of the three modern digitate species; in over 70% of observations digitates occurred in nets below 150 m, and down to 2000 m. The correlation between digitate species and subsurface habitats across multiple epochs suggests that elongated chambers were advantageous for survival in a deep mesopelagic habitat, where food is usually scarce. Increased abundance and diversity of digitates in association with some early and mid-Cretaceous oceanic anoxic events, in middle Eocene regions of coastal and equatorial upwelling, and occasionally in some modern upwelling regions, suggests an additional link with episodes of enhanced ocean productivity associated with expansion of the oxygen minimum zone (OMZ). We suggest that the primary function of digitate chambers was as a feeding specialization that increased effective shell size and food gathering efficiency, for survival in a usually food-poor environment, close to the OMZ. Episodes of increased digitate abundance and ... Article in Journal/Newspaper Planktonic foraminifera Cardiff University: ORCA (Online Research @ Cardiff) Paleobiology 33 4 495 516 |
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Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
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topic |
GC Oceanography QE Geology |
spellingShingle |
GC Oceanography QE Geology Coxall, Helen Kathrine Wilson, Paul A. Pearson, Paul Nicholas Sexton, Phillip Francis Iterative evolution of digitate planktonic foraminifera |
topic_facet |
GC Oceanography QE Geology |
description |
Digitate shell morphologies have evolved repeatedly in planktonic foraminifera throughout the Cretaceous and Cenozoic. Digitate species are usually rare in fossil and modern assemblages but show increased abundance and diversity at times during the Cretaceous and middle Eocene. In this paper we discuss the morphology and stratigraphic distribution of digitate planktonic foraminifera and establish the isotopic depth ecology of fossil ones to draw parallels with modern counterparts. δ18O and δ13C values of six extinct and two modern digitate species, from six time slices (Cenomanian, Turonian, Eocene, Miocene, Pleistocene and Holocene) have similar isotopic depth ecologies, consistently registering the most negative δ13C and usually the most positive δ18O compared to coexisting species. These results indicate a similar deep, subthermocline (>150 m) habitat, characterized by lower temperatures, reduced oxygen, and enrichment of dissolved inorganic carbon. This is consistent with water-column plankton studies that provide insight into the depth preferences of the three modern digitate species; in over 70% of observations digitates occurred in nets below 150 m, and down to 2000 m. The correlation between digitate species and subsurface habitats across multiple epochs suggests that elongated chambers were advantageous for survival in a deep mesopelagic habitat, where food is usually scarce. Increased abundance and diversity of digitates in association with some early and mid-Cretaceous oceanic anoxic events, in middle Eocene regions of coastal and equatorial upwelling, and occasionally in some modern upwelling regions, suggests an additional link with episodes of enhanced ocean productivity associated with expansion of the oxygen minimum zone (OMZ). We suggest that the primary function of digitate chambers was as a feeding specialization that increased effective shell size and food gathering efficiency, for survival in a usually food-poor environment, close to the OMZ. Episodes of increased digitate abundance and ... |
format |
Article in Journal/Newspaper |
author |
Coxall, Helen Kathrine Wilson, Paul A. Pearson, Paul Nicholas Sexton, Phillip Francis |
author_facet |
Coxall, Helen Kathrine Wilson, Paul A. Pearson, Paul Nicholas Sexton, Phillip Francis |
author_sort |
Coxall, Helen Kathrine |
title |
Iterative evolution of digitate planktonic foraminifera |
title_short |
Iterative evolution of digitate planktonic foraminifera |
title_full |
Iterative evolution of digitate planktonic foraminifera |
title_fullStr |
Iterative evolution of digitate planktonic foraminifera |
title_full_unstemmed |
Iterative evolution of digitate planktonic foraminifera |
title_sort |
iterative evolution of digitate planktonic foraminifera |
publisher |
The Paleontological Society |
publishDate |
2007 |
url |
https://orca.cardiff.ac.uk/id/eprint/1371/ https://doi.org/10.1666/06034.1 |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_relation |
Coxall, Helen Kathrine https://orca.cardiff.ac.uk/view/cardiffauthors/A007483I.html, Wilson, Paul A., Pearson, Paul Nicholas https://orca.cardiff.ac.uk/view/cardiffauthors/A0179150.html orcid:0000-0003-4628-9818 orcid:0000-0003-4628-9818 and Sexton, Phillip Francis 2007. Iterative evolution of digitate planktonic foraminifera. Paleobiology 33 (4) , pp. 495-516. 10.1666/06034.1 https://doi.org/10.1666/06034.1 doi:10.1666/06034.1 |
op_doi |
https://doi.org/10.1666/06034.1 |
container_title |
Paleobiology |
container_volume |
33 |
container_issue |
4 |
container_start_page |
495 |
op_container_end_page |
516 |
_version_ |
1766169637068734464 |