Probing the ecology and climate of the Eocene Southern Ocean with sand tiger sharks Striatolamia macrota
- Autor(en)
- Sora L. Kim, Sarah S. Zeichner, Albert S. Colman, Howie D. Scher, Jürgen Kriwet, Thomas Mörs, Matthew Huber
- Abstrakt
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. †Striatolamia 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 Nd (n = 4) results indicate an early Drake Passage opening with Pacific inputs during TELM 2 – 3 (45 – 43 Ma) 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.
- Organisation(en)
- Institut für Paläontologie
- Externe Organisation(en)
- University of California, Merced, California Institute of Technology (Caltech), Rice University, University of South Carolina, Columbia, Purdue University, Swedish Museum of Natural History
- Journal
- Paleoceanography and Paleoclimatology
- Band
- 35
- Anzahl der Seiten
- 21
- ISSN
- 2572-4525
- DOI
- https://doi.org/10.1029/2020PA003997
- Publikationsdatum
- 11-2020
- Peer-reviewed
- Ja
- ÖFOS 2012
- 105118 Paläontologie
- Schlagwörter
- ASJC Scopus Sachgebiete
- Oceanography, Palaeontology, Atmospheric Science
- Sustainable Development Goals
- SDG 14 – Leben unter Wasser, SDG 13 – Maßnahmen zum Klimaschutz
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/950902a1-6bf5-4602-8295-ad499112079a