DOI: 10.6071/m34t1z
title: Data from: Probing the ecology and climate of the Eocene Southern Ocean with sand tiger sharks Striatolamia macrota

description: During the Eocene, the Earth climate system transitioned from greenhouse
 to icehouse conditions. Central to many explanations is the Southern
 Ocean—where tectonic configurations influenced oceanic gateways, ocean
 circulation reduced heat transport, and/or greenhouse gas declines
 prompted glaciation. To date, few studies have explored the implications
 of this climate transition on high latitude, marine vertebrates. Seymour
 Island near the Antarctic Peninsula preserves a rich, diverse fossil
 assemblage in the Tertiary Eocene La Meseta (TELM) Formation (Fm). We
 examine teeth of Striatolamia macrota, an extinct (†) sand tiger shark
 that is abundant throughout the La Meseta Fm. to discern ecological and
 environmental characteristics. Body size is an integrative ecological
 trait often tracked through time and space. †Striatolamia macrota body
 size distributions indicate no shifts during TELMs 2-5 based on anterior
 tooth crown height (n=450, mean=19.6 ± 6.4 mm, total body length 88-389
 cm). Similarly, environmental conditions seem to remain stable through
 this period based on †S. macrota enameloid with mean d18OPO4 value of 21.5
 ± 1.6‰ (n=39) and mean temperature estimates of 22.2 ± 5.4°C. This
 ecological and environmental stasis is intriguing given changes in ocean
 circulation as tracked by neodymium isotope composition. Our preliminary
 eNd (n=4) results indicate an early Drake Passage opening with Pacific
 inputs as early as TELM 2 based on 1 unit variation with an overall
 radiogenic trend, similar to previous results from deep ocean localities.
 We hypothesize that †S. macrota modified its migration behavior to
 preclude environmental changes related to the Drake Passage opening. Our
 results shed important light on paleoceanographic conditions and indicate
 paleoecological responses to climate change.
description: see methods in Kim, S. L., Zeichner, S. S., Colman, A. S., Scher,
 H. D., Kriwet, J., Mörs, T., & Huber, M. (2020). Probing the
 ecology and climate of the Eocene Southern Ocean with sand tiger sharks
 Striatolamia macrota. Paleoceanography and Paleoclimatology, 35,
 e2020PA003997. https://doi.org/10.1029/2020PA003997
description: DS01.csv contains anterior tooth crown height measurements from
 extint <em>Striatolamia macrota</em> teeth found in TELMs 2,
 3, 4, and 5 from the Eocene La Meseta Fm. of Seymour Island. Also included
 are total lengths for extant sand tigers <em>Carcharias
 taurus</em> caught by Dr. Dewayne Fox's research group in the
 Delaware Bay and the estimated anterior tooth crown heights for those
 individuals. Supp_Table1_20-1112.csv includes the
 specimen IDs, collection, TELM, anterior tooth crown height (ATCH), oxygen
 isotope composition (from phosphate) and estimated temperature for data
 included in Kim & Zeichner et al., 2020.
 Supp_Table2_20-1112.csv is clumped isotope and oxygen isotope
 composition (from carbonate) data as well as estimated temperatures and
 oxygen isotope composition of seawater from Douglas et al., 2014. Kim
 & Zeichner et al., (2020) applied a different clumped isotope
 temperature calibration to this previously generated dataset to evaluate
 the effect on estimated temperature and oxygen isotope composition of
 seawater. The two values from cement that were interpreted as altered by
 Douglas et al. (2014) were not included in our analysis.
 Supp_Table3_20-1112.pdf compiles the Eoocene paleoceanography and
 paleoclimateology studies Kim & Zeichner et al. (2020) took into
 consideration in evaluating their results. This literature review was
 quite comprehensie and includes both modeling and empirical datasets
 published from 1991 to 2020. The region, time period, temperature estimate
 for the Southern Ocean, model vs. indicator (i.e., proxy), and
 implications are noted.