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Kim SL, Zeichner SS, Colman AS, Scher HD, Kriwet J, Mörs T, Huber M. Probing the Ecology and Climate of the Eocene Southern Ocean With Sand Tiger Sharks Striatolamia macrota. PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY 2020; 35:e2020PA003997. [PMID: 34222817 PMCID: PMC8246854 DOI: 10.1029/2020pa003997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 10/20/2020] [Accepted: 11/01/2020] [Indexed: 06/13/2023]
Abstract
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 ± 6.4 mm). 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 (45-43 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.
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Affiliation(s)
- Sora L. Kim
- Department of Geophysical SciencesUniversity of ChicagoChicagoILUSA
- Department of Life and Environmental SciencesUniversity of CaliforniaMercedCAUSA
| | - Sarah S. Zeichner
- Department of Geophysical SciencesUniversity of ChicagoChicagoILUSA
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
| | - Albert S. Colman
- Department of Geophysical SciencesUniversity of ChicagoChicagoILUSA
- Department of Earth, Environment, and Planetary SciencesRice UniversityHoustonTXUSA
| | - Howie D. Scher
- Department of Earth, Ocean, and EnvironmentUniversity of South CarolinaColumbiaSCUSA
| | - Jürgen Kriwet
- Department of PalaeontologyUniversity of ViennaViennaAustria
| | - Thomas Mörs
- Department of PalaeobiologySwedish Museum of Natural HistoryStockholmSweden
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
| | - Matthew Huber
- Department of Earth, Atmosphere, and Planetary SciencesPurdue UniversityWest LafayetteINUSA
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Maduna SN, Hull KL, Farrell ED, Boomer JJ, Veríssimo A, Marino IAM, Mazzoldi C, Zane L, Wintner SP, Chesalin MV, da Silva C, Gubili C, Mariani S, Bester-Van Der Merwe AE. Historical biogeography of smoothhound sharks (genus Mustelus) of Southern Africa reveals multiple dispersal events from the Northern Hemisphere. SYST BIODIVERS 2020. [DOI: 10.1080/14772000.2020.1787550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Simo N. Maduna
- Molecular Breeding and Biodiversity Group, Department of Genetics, Stellenbosch University, Private Bag XI, Stellenbosch, 7602, South Africa
- Division of Environment and Natural Resources, Norwegian Institute of Bioeconomy Research (NIBIO), N-1431 Ås, Norway
| | - Kelvin L. Hull
- Molecular Breeding and Biodiversity Group, Department of Genetics, Stellenbosch University, Private Bag XI, Stellenbosch, 7602, South Africa
| | - Edward D. Farrell
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Ireland
| | - Jessica J. Boomer
- Department of Biological Sciences, Macquarie University, 2109 Sydney, NSW, Australia
| | - Ana Veríssimo
- Research Centre in Biodiversity and Genetic Resources, Campus Agrário de Vairão, Rua Padre Armando Quintas, Vairão 4485-661, Portugal
- College of William and Mary, Virginia Institute of Marine Science, Route 1208, Greate Road, Gloucester Point, VA 23062, USA
| | - Ilaria A. M. Marino
- Department of Biology, University of Padova, Via U. Bassi 58/B 35131, Padova, Italy
- Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Roma 00196, Italy
| | - Carlotta Mazzoldi
- Department of Biology, University of Padova, Via U. Bassi 58/B 35131, Padova, Italy
- Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Roma 00196, Italy
| | - Lorenzo Zane
- Department of Biology, University of Padova, Via U. Bassi 58/B 35131, Padova, Italy
- Consorzio Nazionale Interuniversitario per le Scienze del Mare (CoNISMa), Roma 00196, Italy
| | - Sabine P. Wintner
- KwaZulu-Natal Sharks Board, Private Bag 2, Umhlanga Rocks, KwaZulu-Natal 4320, South Africa
- School of Life Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Mikhail V. Chesalin
- A.O. Kovalevsky Institute of Biology of the Southern Seas of RAS, Russian Federation
| | - Charlene da Silva
- Department of Agriculture, Forestry and Fisheries: Branch: Fisheries Research Development, Inshore Research, Private Bag X2, Rogge Bay 8012, South Africa
| | - Chrysoula Gubili
- Fisheries Research Institute, Hellenic Agricultural Organization – DEMETER, Nea Peramos, 64007, Kavala, Greece
| | - Stefano Mariani
- School of Biological & Environmental Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | - Aletta E. Bester-Van Der Merwe
- Molecular Breeding and Biodiversity Group, Department of Genetics, Stellenbosch University, Private Bag XI, Stellenbosch, 7602, South Africa
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First fossil frog from Antarctica: implications for Eocene high latitude climate conditions and Gondwanan cosmopolitanism of Australobatrachia. Sci Rep 2020; 10:5051. [PMID: 32327670 PMCID: PMC7181706 DOI: 10.1038/s41598-020-61973-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 03/04/2020] [Indexed: 11/08/2022] Open
Abstract
Cenozoic ectothermic continental tetrapods (amphibians and reptiles) have not been documented previously from Antarctica, in contrast to all other continents. Here we report a fossil ilium and an ornamented skull bone that can be attributed to the Recent, South American, anuran family Calyptocephalellidae or helmeted frogs, representing the first modern amphibian found in Antarctica. The two bone fragments were recovered in Eocene, approximately 40 million years old, sediments on Seymour Island, Antarctic Peninsula. The record of hyperossified calyptocephalellid frogs outside South America supports Gondwanan cosmopolitanism of the anuran clade Australobatrachia. Our results demonstrate that Eocene freshwater ecosystems in Antarctica provided habitats favourable for ectothermic vertebrates (with mean annual precipitation ≥900 mm, coldest month mean temperature ≥3.75 °C, and warmest month mean temperature ≥13.79 °C), at a time when there were at least ephemeral ice sheets existing on the highlands within the interior of the continent.
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