A proximal perspective to the Eocene Drake Passage: environmental reconstruction and habitat use based on δ18O of fossil shark teeth from Seymour Island, Antarctica

Tectonic changes in the Southern Ocean likely triggered global cooling across the Eocene, yet the evidence for when the Drake Passage opened remains ambiguous. This climatic-tectonic change likely impacted marine ecosystems, including sharks that inhabited high-latitude regions. The fossil record could provide insights into sharks’ response to global cooling over the Eocene, but paleoecological studies are few. The Middle-to-Late Eocene units on Seymour Island provide a rich, diverse fossil record, including that of sharks. We analyzed the oxygen isotope composition of phosphate from shark tooth bioapatite (δ18Op) and compared to results of co-occurring bivalves and predictions from an isotope-enabled global climate model output to investigate habitat use and environmental conditions. Bulk δ18Op values (mean 22.0 ± 1.3‰) show no significant changes through time, and variation exceeds that in simulated seasonal and regional values. Pelagic and benthic taxa exhibit similar values across u..., See methods in Larocca Conte, G., Aleksinski, A.,  Liao, A., Kriwet, J., Mörs, T., Trayler, R. B., Ivany, L. C., Huber, M., Kim, S. L. (2024). A proximal perspective to the Eocene Drake Passage: environmental reconstruction and habitat use based on fossil shark teeth from Seymour Island, Antarctica. Paleoceanography and Paleoclimatology (in review)., , # Data from: A proximal perspective to the Eocene Drake Passage: environmental reconstruction and habitat use based on fossil shark teeth from Seymour Island, Antarctica.

[https://doi.org/10.5061/dryad.qz612jmq2](https://doi.org/10.5061/dryad.qz612jmq2)

The repository folder includes scripts and spreadsheets for phosphate oxygen stable isotope (δ18Op) analysis measured from shark tooth biogenic apatite collected from the Eocene deposits of the La Meseta and Submeseta formations (West Antarctica, Seymour Island). It also contains Fourier-Transform Infrared Spectroscopy (FTIR) analysis, a Bayesian model for temperature estimates, and model output extraction scripts from the iCESM simulation for the Early Eocene (Zhu et al., 2020). Scripts and data are stored in specific folders on the type of analysis. All scripts are in R or Python language.   

**Usage notes**

**1 \"iCESM modeling scripts\" directory**

The folder includes scripts in Jupiter Notebook format for extracting and plotting ...