Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota.
Many explanations for Eocene climate change focus on the Southern Ocean-where tectonics influenced oceanic gateways, ocean circulation reduced heat transport, and greenhouse gas declines prompted glaciation. To date, few studies focus on marine vertebrates at high latitudes to discern paleoecologica...
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ftcdlib:oai:escholarship.org/ark:/13030/qt5808g3sf 2023-05-15T16:02:30+02:00 Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota. Kim, Sora L Zeichner, Sarah S Colman, Albert S Scher, Howie D Kriwet, Jürgen Mörs, Thomas Huber, Matthew e2020PA003997 2020-12-08 application/pdf https://escholarship.org/uc/item/5808g3sf unknown eScholarship, University of California qt5808g3sf https://escholarship.org/uc/item/5808g3sf public Paleoceanography and paleoclimatology, vol 35, iss 12 Seymour Island neodymium isotope analysis oxygen isotope analysis paleobiology paleoclimate temperature article 2020 ftcdlib 2021-08-02T17:10:09Z Many explanations for Eocene climate change focus on the Southern Ocean-where tectonics influenced oceanic gateways, ocean circulation reduced heat transport, and greenhouse gas declines prompted glaciation. To date, few studies focus on marine vertebrates at high latitudes to discern paleoecological and paleoenvironmental impacts of this climate transition. The Tertiary Eocene La Meseta (TELM) Formation has a rich fossil assemblage to characterize these impacts; Striatolamia macrota, an extinct (†) sand tiger shark, is abundant throughout the La Meseta Formation. Body size is often tracked to characterize and integrate across multiple ecological dimensions. †S.macrota body size distributions indicate limited changes during TELMs 2-5 based on anterior tooth crown height (n=450, mean=19.6±6.4mm). Similarly, environmental conditions remained stable through this period based on δ18OPO4 values from tooth enameloid (n=42; 21.5±1.6‰), which corresponds to a mean temperature of 22.0±4.0°C. Our preliminary ε Nd (n=4) results indicate an early Drake Passage opening with Pacific inputs during TELM 2-3 (45-43Ma) based on single unit variation with an overall radiogenic trend. Two possible hypotheses to explain these observations are (1) †S.macrota modified its migration behavior to ameliorate environmental changes related to the Drake Passage opening, or (2) the local climate change was small and gateway opening had little impact. While we cannot rule out an ecological explanation, a comparison with climate model results suggests that increased CO2 produces warm conditions that also parsimoniously explain the observations. Article in Journal/Newspaper Drake Passage Seymour Island Southern Ocean University of California: eScholarship Southern Ocean Drake Passage Pacific Seymour ENVELOPE(-56.767,-56.767,-64.283,-64.283) Seymour Island ENVELOPE(-56.750,-56.750,-64.283,-64.283) |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Seymour Island neodymium isotope analysis oxygen isotope analysis paleobiology paleoclimate temperature |
spellingShingle |
Seymour Island neodymium isotope analysis oxygen isotope analysis paleobiology paleoclimate temperature Kim, Sora L Zeichner, Sarah S Colman, Albert S Scher, Howie D Kriwet, Jürgen Mörs, Thomas Huber, Matthew Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota. |
topic_facet |
Seymour Island neodymium isotope analysis oxygen isotope analysis paleobiology paleoclimate temperature |
description |
Many explanations for Eocene climate change focus on the Southern Ocean-where tectonics influenced oceanic gateways, ocean circulation reduced heat transport, and greenhouse gas declines prompted glaciation. To date, few studies focus on marine vertebrates at high latitudes to discern paleoecological and paleoenvironmental impacts of this climate transition. The Tertiary Eocene La Meseta (TELM) Formation has a rich fossil assemblage to characterize these impacts; Striatolamia macrota, an extinct (†) sand tiger shark, is abundant throughout the La Meseta Formation. Body size is often tracked to characterize and integrate across multiple ecological dimensions. †S.macrota body size distributions indicate limited changes during TELMs 2-5 based on anterior tooth crown height (n=450, mean=19.6±6.4mm). Similarly, environmental conditions remained stable through this period based on δ18OPO4 values from tooth enameloid (n=42; 21.5±1.6‰), which corresponds to a mean temperature of 22.0±4.0°C. Our preliminary ε Nd (n=4) results indicate an early Drake Passage opening with Pacific inputs during TELM 2-3 (45-43Ma) based on single unit variation with an overall radiogenic trend. Two possible hypotheses to explain these observations are (1) †S.macrota modified its migration behavior to ameliorate environmental changes related to the Drake Passage opening, or (2) the local climate change was small and gateway opening had little impact. While we cannot rule out an ecological explanation, a comparison with climate model results suggests that increased CO2 produces warm conditions that also parsimoniously explain the observations. |
format |
Article in Journal/Newspaper |
author |
Kim, Sora L Zeichner, Sarah S Colman, Albert S Scher, Howie D Kriwet, Jürgen Mörs, Thomas Huber, Matthew |
author_facet |
Kim, Sora L Zeichner, Sarah S Colman, Albert S Scher, Howie D Kriwet, Jürgen Mörs, Thomas Huber, Matthew |
author_sort |
Kim, Sora L |
title |
Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota. |
title_short |
Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota. |
title_full |
Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota. |
title_fullStr |
Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota. |
title_full_unstemmed |
Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota. |
title_sort |
probing the ecology and climate of the eocene southern ocean with sand tiger sharks striatolamia macrota. |
publisher |
eScholarship, University of California |
publishDate |
2020 |
url |
https://escholarship.org/uc/item/5808g3sf |
op_coverage |
e2020PA003997 |
long_lat |
ENVELOPE(-56.767,-56.767,-64.283,-64.283) ENVELOPE(-56.750,-56.750,-64.283,-64.283) |
geographic |
Southern Ocean Drake Passage Pacific Seymour Seymour Island |
geographic_facet |
Southern Ocean Drake Passage Pacific Seymour Seymour Island |
genre |
Drake Passage Seymour Island Southern Ocean |
genre_facet |
Drake Passage Seymour Island Southern Ocean |
op_source |
Paleoceanography and paleoclimatology, vol 35, iss 12 |
op_relation |
qt5808g3sf https://escholarship.org/uc/item/5808g3sf |
op_rights |
public |
_version_ |
1766398159752265728 |