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Kiel S, Goedert JL, Huynh TL, Krings M, Parkinson D, Romero R, Looy CV. Early Oligocene kelp holdfasts and stepwise evolution of the kelp ecosystem in the North Pacific. Proc Natl Acad Sci U S A 2024; 121:e2317054121. [PMID: 38227671 PMCID: PMC10823212 DOI: 10.1073/pnas.2317054121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 11/27/2023] [Indexed: 01/18/2024] Open
Abstract
Kelp forests are highly productive and economically important ecosystems worldwide, especially in the North Pacific Ocean. However, current hypotheses for their evolutionary origins are reliant on a scant fossil record. Here, we report fossil hapteral kelp holdfasts from western Washington State, USA, indicating that kelp has existed in the northeastern Pacific Ocean since the earliest Oligocene. This is consistent with the proposed North Pacific origin of kelp associated with global cooling around the Eocene-Oligocene transition. These fossils also support the hypotheses that a hapteral holdfast, rather than a discoid holdfast, is the ancestral state in complex kelps and suggest that early kelps likely had a flexible rather than a stiff stipe. Early kelps were possibly grazed upon by mammals like desmostylians, but fossil evidence of the complex ecological interactions known from extant kelp forests is lacking. The fossil record further indicates that the present-day, multi-story kelp forest had developed at latest after the mid-Miocene climate optimum. In summary, the fossils signify a stepwise evolution of the kelp ecosystem in the North Pacific, likely enabled by changes in the ocean-climate system.
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Affiliation(s)
- Steffen Kiel
- Department of Palaeobiology, Swedish Museum of Natural History, Stockholm10405, Sweden
| | - James L. Goedert
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA98195
| | - Tony L. Huynh
- School of Medicine, University of California, San Francisco, CA94143
| | - Michael Krings
- Staatliche Naturwissenschaftliche Sammlungen Bayerns-Bayerische Staatssammlung für Paläontologie und Geologie, Munich80333, Germany
- Department für Geo- und Umweltwissenschaften, Paläontologie und Geobiologie, Ludwig-Maximilians-Universität, Munich80333, Germany
| | - Dula Parkinson
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Rosemary Romero
- Department of Integrative Biology, University of California, Berkeley, CA94720
| | - Cindy V. Looy
- Department of Integrative Biology, Museum of Paleontology, and Herbarium, University of California, Berkeley, CA94720
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2
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Hoefs J, Harmon RS. Isotopic history of seawater: the stable isotope character of the global ocean at present and in the geological past. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2023; 59:349-411. [PMID: 37877261 DOI: 10.1080/10256016.2023.2271127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 09/10/2023] [Indexed: 10/26/2023]
Abstract
After the atmosphere, the ocean is the most well-mixed and homogeneous global geochemical reservoir. Both physical and biological processes generate elemental and isotope variations in seawater. Contrasting geochemical behaviors cause elements to be susceptible to different fractionation mechanisms, with their isotopes providing unique insights into the composition and evolution of the ocean over the course of geological history. Supplementing the traditional stable isotopes (H, C, O, N, S) that provide information about ocean processes and past environmental conditions, radiogenic isotope (Sr, Nd, Os, Pb, U) systems can be used as time markers, indicators of terrestrial weathering, and ocean water mass mixing. Recent instrumentation advances have made possible the measurement of natural stable isotope variations produced by both mass-dependent and mass-independent fractionation for an ever-increasing number of metal elements (e.g. Li, B, Mg, Si, Ca, V, Cr, Fe, Ni, Cu, Zn, Se, Mo, Cd, Tl, U). The major emphasis in this review is on the isotopic composition of the light elements based on a comparatively large literature. Unlike O, H and S, the stable isotopes of C, N and Si do not have a constant isotopic composition in the modern ocean. The major cations Ca, Mg, and Sr fixed in carbonate shells provide the best proxies for reconstruction of the composition of the ocean in the past. Exhibiting large isotope enrichments in ocean water, B and Li are suitable for the investigation of water/rock interactions and can act as monitors of former oceanic pH. The bioessential elements Zn, Cd, and Ni are indicators of paleoproductivity in the ocean. Characteristic isotope enrichments or depletions of the multivalent elements V, Cr, Fe, Se, Mo, and U record the past redox state of the ocean/atmosphere system. Case studies describe how isotopes have been used to define the seawater composition in the geological past.
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Affiliation(s)
- Jochen Hoefs
- Geowissenschaftliches Zentrum, Universität Göttingen, Göttingen, Germany
| | - Russell S Harmon
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA
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3
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Fenton IS, Aze T, Farnsworth A, Valdes P, Saupe EE. Origination of the modern-style diversity gradient 15 million years ago. Nature 2023; 614:708-712. [PMID: 36792825 DOI: 10.1038/s41586-023-05712-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 01/06/2023] [Indexed: 02/17/2023]
Abstract
The latitudinal diversity gradient (LDG) is a prevalent feature of modern ecosystems across diverse clades1-4. Recognized for well over a century, the causal mechanisms for LDGs remain disputed, in part because numerous putative drivers simultaneously covary with latitude1,3,5. The past provides the opportunity to disentangle LDG mechanisms because the relationships among biodiversity, latitude and possible causal factors have varied over time6-9. Here we quantify the emergence of the LDG in planktonic foraminifera at high spatiotemporal resolution over the past 40 million years, finding that a modern-style gradient arose only 15 million years ago. Spatial and temporal models suggest that LDGs for planktonic foraminifera may be controlled by the physical structure of the water column. Steepening of the latitudinal temperature gradient over 15 million years ago, associated with an increased vertical temperature gradient at low latitudes, may have enhanced niche partitioning and provided more opportunities for speciation at low latitudes. Supporting this hypothesis, we find that higher rates of low-latitude speciation steepened the diversity gradient, consistent with spatiotemporal patterns of depth partitioning by planktonic foraminifera. Extirpation of species from high latitudes also strengthened the LDG, but this effect tended to be weaker than speciation. Our results provide a step change in understanding the evolution of marine LDGs over long timescales.
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Affiliation(s)
- Isabel S Fenton
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - Tracy Aze
- School of Earth and Environment, University of Leeds, Leeds, UK
| | - Alexander Farnsworth
- School of Geographical Sciences, University of Bristol, Bristol, UK.,State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Paul Valdes
- School of Geographical Sciences, University of Bristol, Bristol, UK
| | - Erin E Saupe
- Department of Earth Sciences, University of Oxford, Oxford, UK.
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4
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Understanding the crystallographic and nanomechanical properties of bryozoans. J Struct Biol 2022; 214:107882. [PMID: 35850322 DOI: 10.1016/j.jsb.2022.107882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 07/08/2022] [Accepted: 07/12/2022] [Indexed: 11/23/2022]
Abstract
This study examines how microscale differences in skeletal ultrastructure affect the crystallographic and nanomechanical properties of two related bryozoan species: (i) Hornera currieae, which is found at relatively quiescent depths of c. 1000 m, and (ii) Hornera robusta, which lives at depths of 50-400 m where it is exposed to currents and storm waves. Microstructural and Electron Backscatter Diffraction (EBSD) observations show that in both species the secondary walls are composed of low-Mg calcite crystallites that grow with their c-axes perpendicular to the wall. Branches in H. currieae develop a strong preferred orientation of the calcite c-axes, while in H. robusta the c-axes are more scattered. Microstructural observations suggest that the degree of scattering is controlled by the underlying morphology of the skeletons: in H. currieae the laminated branch walls are smooth and relatively uninterrupted, whereas the wall architecture of H. robusta is modified by numerous deflections, forming pustules and ridges associated with microscopic tubules. Modelling of the Young's modulus and measurements of nanoindentation hardness indicate that the observed scattering of the crystallite c-axes affects the elastic modulus and nanohardness of the branches, and therefore controls the mechanical properties of the skeletal walls. At relatively high pressure in deep waters, the anisotropic skeletal architecture of H. currieae is aimed at concentrating elasticity normal to the skeleton wall. In comparison, in the relatively shallow and active hydrographic regime of the continental shelf, the elastically isotropic skeleton of H. robusta is designed to increase protection from external predators and stronger omni-directional currents.
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5
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Meckler AN, Sexton PF, Piasecki AM, Leutert TJ, Marquardt J, Ziegler M, Agterhuis T, Lourens LJ, Rae JWB, Barnet J, Tripati A, Bernasconi SM. Cenozoic evolution of deep ocean temperature from clumped isotope thermometry. Science 2022; 377:86-90. [PMID: 35771913 DOI: 10.1126/science.abk0604] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Characterizing past climate states is crucial for understanding the future consequences of ongoing greenhouse gas emissions. Here, we revisit the benchmark time series for deep ocean temperature across the past 65 million years using clumped isotope thermometry. Our temperature estimates from the deep Atlantic Ocean are overall much warmer compared with oxygen isotope-based reconstructions, highlighting the likely influence of changes in deep ocean pH and/or seawater oxygen isotope composition on classical oxygen isotope records of the Cenozoic. In addition, our data reveal previously unrecognized large swings in deep ocean temperature during early Eocene acute greenhouse warmth. Our results call for a reassessment of the Cenozoic history of ocean temperatures to achieve a more accurate understanding of the nature of climatic responses to tectonic events and variable greenhouse forcing.
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Affiliation(s)
- A N Meckler
- Bjerknes Centre for Climate Research and Department of Earth Science, University of Bergen, Bergen, Norway
| | - P F Sexton
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
| | - A M Piasecki
- Bjerknes Centre for Climate Research and Department of Earth Science, University of Bergen, Bergen, Norway
| | - T J Leutert
- Bjerknes Centre for Climate Research and Department of Earth Science, University of Bergen, Bergen, Norway
| | - J Marquardt
- Bjerknes Centre for Climate Research and Department of Earth Science, University of Bergen, Bergen, Norway
| | - M Ziegler
- Faculty of Geosciences, Utrecht University, Utrecht, Netherlands
| | - T Agterhuis
- Faculty of Geosciences, Utrecht University, Utrecht, Netherlands
| | - L J Lourens
- Faculty of Geosciences, Utrecht University, Utrecht, Netherlands
| | - J W B Rae
- School of Earth and Environmental Sciences, University of St. Andrews, St. Andrews, UK
| | - J Barnet
- School of Earth and Environmental Sciences, University of St. Andrews, St. Andrews, UK
| | - A Tripati
- Department of Earth, Planetary, and Space Science, Department of Atmospheric and Oceanic Science, Institute of the Environment and Sustainability, American Indian Studies Center, Center for Diverse Leadership in Science, University of California, Los Angeles, Los Angeles, USA
| | - S M Bernasconi
- Department of Earth Science, ETH Zürich, Zürich, Switzerland
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6
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Climate transition at the Eocene-Oligocene influenced by bathymetric changes to the Atlantic-Arctic oceanic gateways. Proc Natl Acad Sci U S A 2022; 119:e2115346119. [PMID: 35446685 PMCID: PMC9169914 DOI: 10.1073/pnas.2115346119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The results show that dynamic variations in the Earth’s interior could have played a key role in the Eocene–Oligocene climatic transition (∼33.9 Ma) and the inception of glaciations. Pulsations in the Iceland mantle plume modified the bathymetry of the Greenland–Scotland Ridge, which affected deep water formation in the North Atlantic. Our model simulations show that the changes in the Atlantic–Arctic oceanic gateways cooled the Southern Hemisphere, and later the Northern Hemisphere, paving the way for the growth of major land-based ice sheets. This supplements the current view that decreasing atmospheric CO2 concentrations and/or changes to the Southern Ocean gateways or the Tethys Seaway dominated climate changes and the inception of glaciations at the time. The Eocene–Oligocene Transition (∼33.9 Ma) marks the largest step transformation within the Cenozoic cooling trend and is characterized by a sudden growth of the Antarctic ice sheets, cooling of the interior ocean, and the establishment of strong meridional temperature gradients. Here we examine the climatic impact of oceanic gateway changes at the Eocene–Oligocene Transition by implementing detailed paleogeographic reconstructions with realistic paleobathymetric models for the Atlantic–Arctic basins in a state-of-the-art earth system model (the Norwegian Earth System Model [NorESM-F]). We demonstrate that the warm Eocene climate is highly sensitive to depth variations of the Greenland–Scotland Ridge and the proto–Fram Strait as they control the freshwater leakage from the Arctic to the North Atlantic. Our results, and proxy evidence, suggest that changes in these gateways controlled the ocean circulation and played a critical role in the growth of land-based ice sheets, alongside CO2-driven global cooling. Specifically, we suggest that a shallow connection between the Arctic and North Atlantic restricted the southward flow of fresh surface waters during the Late Eocene allowing for a North Atlantic overturning circulation. Consequently, the Southern Hemisphere cooled by several degrees paving the way for the glaciation of Antarctica. Shortly after, the connection to the Arctic deepened due to weakening dynamic support from the Iceland Mantle Plume. This weakened the North Atlantic overturning and cooled the Northern Hemisphere, thereby promoting glaciations there. Our study points to a controlling role of the Northeast Atlantic gateways and decreasing atmospheric CO2 in the onset of glaciations in both hemispheres.
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7
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Sauermilch I, Whittaker JM, Klocker A, Munday DR, Hochmuth K, Bijl PK, LaCasce JH. Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling. Nat Commun 2021; 12:6465. [PMID: 34753912 PMCID: PMC8578591 DOI: 10.1038/s41467-021-26658-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/08/2021] [Indexed: 11/09/2022] Open
Abstract
Declining atmospheric CO2 concentrations are considered the primary driver for the Cenozoic Greenhouse-Icehouse transition, ~34 million years ago. A role for tectonically opening Southern Ocean gateways, initiating the onset of a thermally isolating Antarctic Circumpolar Current, has been disputed as ocean models have not reproduced expected heat transport to the Antarctic coast. Here we use high-resolution ocean simulations with detailed paleobathymetry to demonstrate that tectonics did play a fundamental role in reorganising Southern Ocean circulation patterns and heat transport, consistent with available proxy data. When at least one gateway (Tasmanian or Drake) is shallow (300 m), gyres transport warm waters towards Antarctica. When the second gateway subsides below 300 m, these gyres weaken and cause a dramatic cooling (average of 2–4 °C, up to 5 °C) of Antarctic surface waters whilst the ACC remains weak. Our results demonstrate that tectonic changes are crucial for Southern Ocean climate change and should be carefully considered in constraining long-term climate sensitivity to CO2. The role of Southern Ocean gateways contributing to the Eocene-Oligocene climate transition is still debated. Here, the authors present high-resolution ocean simulations to show that gateways opening led to a reorganization of ocean circulation, heat transport and Antarctic surface water cooling.
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Affiliation(s)
- Isabel Sauermilch
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia. .,Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands.
| | - Joanne M Whittaker
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Andreas Klocker
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia.,Australian Research Council Centre of Excellence for Climate Extremes, University of Tasmania, Hobart, Australia
| | | | - Katharina Hochmuth
- Alfred Wegener Institute Helmholtz Center for Polar and Marine Research, Bremerhaven, Germany.,School of Geography, Geology and the Environment, University of Leicester, Leicester, UK
| | - Peter K Bijl
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
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8
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Marciniak S, Mughal MR, Godfrey LR, Bankoff RJ, Randrianatoandro H, Crowley BE, Bergey CM, Muldoon KM, Randrianasy J, Raharivololona BM, Schuster SC, Malhi RS, Yoder AD, Louis EE, Kistler L, Perry GH. Evolutionary and phylogenetic insights from a nuclear genome sequence of the extinct, giant, "subfossil" koala lemur Megaladapis edwardsi. Proc Natl Acad Sci U S A 2021; 118:e2022117118. [PMID: 34162703 PMCID: PMC8255780 DOI: 10.1073/pnas.2022117118] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
No endemic Madagascar animal with body mass >10 kg survived a relatively recent wave of extinction on the island. From morphological and isotopic analyses of skeletal "subfossil" remains we can reconstruct some of the biology and behavioral ecology of giant lemurs (primates; up to ∼160 kg) and other extraordinary Malagasy megafauna that survived into the past millennium. Yet, much about the evolutionary biology of these now-extinct species remains unknown, along with persistent phylogenetic uncertainty in some cases. Thankfully, despite the challenges of DNA preservation in tropical and subtropical environments, technical advances have enabled the recovery of ancient DNA from some Malagasy subfossil specimens. Here, we present a nuclear genome sequence (∼2× coverage) for one of the largest extinct lemurs, the koala lemur Megaladapis edwardsi (∼85 kg). To support the testing of key phylogenetic and evolutionary hypotheses, we also generated high-coverage nuclear genomes for two extant lemurs, Eulemur rufifrons and Lepilemur mustelinus, and we aligned these sequences with previously published genomes for three other extant lemurs and 47 nonlemur vertebrates. Our phylogenetic results confirm that Megaladapis is most closely related to the extant Lemuridae (typified in our analysis by E. rufifrons) to the exclusion of L. mustelinus, which contradicts morphology-based phylogenies. Our evolutionary analyses identified significant convergent evolution between M. edwardsi and an extant folivore (a colobine monkey) and an herbivore (horse) in genes encoding proteins that function in plant toxin biodegradation and nutrient absorption. These results suggest that koala lemurs were highly adapted to a leaf-based diet, which may also explain their convergent craniodental morphology with the small-bodied folivore Lepilemur.
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Affiliation(s)
- Stephanie Marciniak
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802
| | - Mehreen R Mughal
- Bioinformatics and Genomics Intercollege Graduate Program, Pennsylvania State University, University Park, PA 16082
| | - Laurie R Godfrey
- Department of Anthropology, University of Massachusetts, Amherst, MA 01003
| | - Richard J Bankoff
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802
| | - Heritiana Randrianatoandro
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802
- Mention Anthropobiologie et Développement Durable, Faculté des Sciences, Université d'Antananarivo, Antananarivo 101, Madagascar
| | - Brooke E Crowley
- Department of Geology, University of Cincinnati, Cincinnati, OH 45220
- Department of Anthropology, University of Cincinnati, Cincinnati, OH 45220
| | - Christina M Bergey
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802
- Department of Biology, Pennsylvania State University, University Park, PA 16802
- Department of Genetics, Rutgers University, New Brunswick, NJ 08854
| | | | - Jeannot Randrianasy
- Mention Anthropobiologie et Développement Durable, Faculté des Sciences, Université d'Antananarivo, Antananarivo 101, Madagascar
| | - Brigitte M Raharivololona
- Mention Anthropobiologie et Développement Durable, Faculté des Sciences, Université d'Antananarivo, Antananarivo 101, Madagascar
| | - Stephan C Schuster
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 639798
| | - Ripan S Malhi
- Department of Anthropology, University of Illinois Urbana-Champaign, Urbana, IL 61801
- Department of Ecology, Evolution and Behavior, Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801
| | - Anne D Yoder
- Department of Biology, Duke University, Durham, NC 27708
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708
| | - Edward E Louis
- Department of Conservation Genetics, Omaha's Henry Doorly Zoo and Aquarium, Omaha, NE 68107;
| | - Logan Kistler
- Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560;
| | - George H Perry
- Department of Anthropology, Pennsylvania State University, University Park, PA 16802;
- Bioinformatics and Genomics Intercollege Graduate Program, Pennsylvania State University, University Park, PA 16082
- Department of Biology, Pennsylvania State University, University Park, PA 16802
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802
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9
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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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10
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Folk RA, Siniscalchi CM, Soltis DE. Angiosperms at the edge: Extremity, diversity, and phylogeny. PLANT, CELL & ENVIRONMENT 2020; 43:2871-2893. [PMID: 32926444 DOI: 10.1111/pce.13887] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/21/2020] [Accepted: 08/13/2020] [Indexed: 05/26/2023]
Abstract
A hallmark of flowering plants is their ability to invade some of the most extreme and dynamic habitats, including cold and dry biomes, to a far greater extent than other land plants. Recent work has provided insight to the phylogenetic distribution and evolutionary mechanisms which have enabled this success, yet needed is a synthesis of evolutionary perspectives with plant physiological traits, morphology, and genomic diversity. Linking these disparate components will not only lead to better understand the evolutionary parallelism and diversification of plants with these two strategies, but also to provide the framework needed for directing future research. We summarize the primary physiological and structural traits involved in response to cold- and drought stress, outline the phylogenetic distribution of these adaptations, and describe the recurring association of these changes with rapid diversification events that occurred in multiple lineages over the past 15 million years. Across these threefold facets of dry-cold correlation (traits, phylogeny, and time) we stress the contrast between (a) the amazing diversity of solutions flowering plants have developed in the face of extreme environments and (b) a broad correlation between cold and dry adaptations that in some cases may hint at deep common origins.
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Affiliation(s)
- Ryan A Folk
- Department of Biological Sciences, Mississippi State University, Mississippi State, Mississippi, USA
| | - Carolina M Siniscalchi
- Department of Biological Sciences, Mississippi State University, Mississippi State, Mississippi, USA
| | - Douglas E Soltis
- Florida Museum of Natural History, University of Florida, Gainesville, Florida, USA
- Department of Biology, University of Florida, Gainesville, Florida, USA
- Biodiversity Institute, University of Florida, Gainesville, Florida, USA
- Genetics Institute, University of Florida, Gainesville, Florida, USA
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11
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Abstract
During the Eocene, high-latitude regions were much warmer than today and substantial polar ice sheets were lacking. Indeed, the initiation of significant polar ice sheets near the end of the Eocene has been closely linked to global cooling. Here, we examine the relationship between global temperatures and continental-scale polar ice sheets following the establishment of ice sheets on Antarctica ∼34 million years ago, using records of surface temperatures from around the world. We find that high-latitude temperatures were almost as warm after the initiation of Antarctic glaciation as before, challenging our basic understanding of how climate works, and of the development of climate and ice volume through time. Falling atmospheric CO2 levels led to cooling through the Eocene and the expansion of Antarctic ice sheets close to their modern size near the beginning of the Oligocene, a period of poorly documented climate. Here, we present a record of climate evolution across the entire Oligocene (33.9 to 23.0 Ma) based on TEX86 sea surface temperature (SST) estimates from southwestern Atlantic Deep Sea Drilling Project Site 516 (paleolatitude ∼36°S) and western equatorial Atlantic Ocean Drilling Project Site 929 (paleolatitude ∼0°), combined with a compilation of existing SST records and climate modeling. In this relatively low CO2 Oligocene world (∼300 to 700 ppm), warm climates similar to those of the late Eocene continued with only brief interruptions, while the Antarctic ice sheet waxed and waned. SSTs are spatially heterogenous, but generally support late Oligocene warming coincident with declining atmospheric CO2. This Oligocene warmth, especially at high latitudes, belies a simple relationship between climate and atmospheric CO2 and/or ocean gateways, and is only partially explained by current climate models. Although the dominant climate drivers of this enigmatic Oligocene world remain unclear, our results help fill a gap in understanding past Cenozoic climates and the way long-term climate sensitivity responded to varying background climate states.
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Godfrey LR, Samonds KE, Baldwin JW, Sutherland MR, Kamilar JM, Allfisher KL. Mid-Cenozoic climate change, extinction, and faunal turnover in Madagascar, and their bearing on the evolution of lemurs. BMC Evol Biol 2020; 20:97. [PMID: 32770933 PMCID: PMC7414565 DOI: 10.1186/s12862-020-01628-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 05/18/2020] [Indexed: 01/16/2023] Open
Abstract
Background Was there a mid-Cenozoic vertebrate extinction and recovery event in Madagascar and, if so, what are its implications for the evolution of lemurs? The near lack of an early and mid-Cenozoic fossil record on Madagascar has inhibited direct testing of any such hypotheses. We compare the terrestrial vertebrate fauna of Madagascar in the Holocene to that of early Cenozoic continental Africa to shed light on the probability of a major mid-Cenozoic lemur extinction event, followed by an “adaptive radiation” or recovery. We also use multiple analytic approaches to test competing models of lemur diversification and the null hypothesis that no unusual mid-Cenozoic extinction of lemurs occurred. Results Comparisons of the terrestrial vertebrate faunas of the early Cenozoic on continental Africa and Holocene on Madagascar support the inference that Madagascar suffered a major mid-Cenozoic extinction event. Evolutionary modeling offers some corroboration, although the level of support varies by phylogeny and model used. Using the lemur phylogeny and divergence dates generated by Kistler and colleagues, RPANDA and TESS offer moderate support for the occurrence of unusual extinction at or near the Eocene-Oligocene (E-O) boundary (34 Ma). TreePar, operating under the condition of obligate mass extinction, found peak diversification at 31 Ma, and low probability of survival of prior lineages. Extinction at the E-O boundary received greater support than other candidate extinctions or the null hypothesis of no major extinction. Using the lemur phylogeny and divergence dates generated by Herrera & Dàvalos, evidence for large-scale extinction diminishes and its most likely timing shifts to before 40 Ma, which fails to conform to global expectations. Conclusions While support for large-scale mid-Cenozoic lemur extinction on Madagascar based on phylogenetic modeling is inconclusive, the African fossil record does provide indirect support. Furthermore, a major extinction and recovery of lemuriforms during the Eocene-Oligocene transition (EOT) would coincide with other major vertebrate extinctions in North America, Europe, and Africa. It would suggest that Madagascar’s lemurs were impacted by the climate shift from “greenhouse” to “ice-house” conditions that occurred at that time. This could, in turn, help to explain some of the peculiar characteristics of the lemuriform clade.
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Affiliation(s)
- Laurie R Godfrey
- Department of Anthropology, University of Massachusetts, 217 Machmer Hall, 240 Hicks Way, Amherst, MA, 01003, USA.
| | - Karen E Samonds
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Justin W Baldwin
- Department of Public Health, School of Biostatistics and Epidemiology, University of Massachusetts, Amherst, MA, 01003, USA.,Present Address: Department of Biology, Washington University, St. Louis, MO, 63130, USA
| | - Michael R Sutherland
- Department of Mathematics and Statistics, University of Massachusetts, Amherst, MA, 01003, USA
| | - Jason M Kamilar
- Department of Anthropology, University of Massachusetts, 217 Machmer Hall, 240 Hicks Way, Amherst, MA, 01003, USA
| | - Kristen L Allfisher
- Department of Anthropology, University of Massachusetts, 217 Machmer Hall, 240 Hicks Way, Amherst, MA, 01003, USA.,Present Address: USDA, APHIS, Riverdale, MD, 20737, USA
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Miller KG, Browning JV, Schmelz WJ, Kopp RE, Mountain GS, Wright JD. Cenozoic sea-level and cryospheric evolution from deep-sea geochemical and continental margin records. SCIENCE ADVANCES 2020; 6:eaaz1346. [PMID: 32440543 PMCID: PMC7228749 DOI: 10.1126/sciadv.aaz1346] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 03/16/2020] [Indexed: 05/14/2023]
Abstract
Using Pacific benthic foraminiferal δ18O and Mg/Ca records, we derive a Cenozoic (66 Ma) global mean sea level (GMSL) estimate that records evolution from an ice-free Early Eocene to Quaternary bipolar ice sheets. These GMSL estimates are statistically similar to "backstripped" estimates from continental margins accounting for compaction, loading, and thermal subsidence. Peak warmth, elevated GMSL, high CO2, and ice-free "Hothouse" conditions (56 to 48 Ma) were followed by "Cool Greenhouse" (48 to 34 Ma) ice sheets (10 to 30 m changes). Continental-scale ice sheets ("Icehouse") began ~34 Ma (>50 m changes), permanent East Antarctic ice sheets at 12.8 Ma, and bipolar glaciation at 2.5 Ma. The largest GMSL fall (27 to 20 ka; ~130 m) was followed by a >40 mm/yr rise (19 to 10 ka), a slowing (10 to 2 ka), and a stillstand until ~1900 CE, when rates began to rise. High long-term CO2 caused warm climates and high sea levels, with sea-level variability dominated by periodic Milankovitch cycles.
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Affiliation(s)
- Kenneth G. Miller
- Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA
- Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, New Brunswick, NJ 08901, USA
- Corresponding author.
| | - James V. Browning
- Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA
- Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, New Brunswick, NJ 08901, USA
| | - W. John Schmelz
- Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA
- Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, New Brunswick, NJ 08901, USA
| | - Robert E. Kopp
- Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA
- Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, New Brunswick, NJ 08901, USA
| | - Gregory S. Mountain
- Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA
- Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, New Brunswick, NJ 08901, USA
| | - James D. Wright
- Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA
- Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, New Brunswick, NJ 08901, USA
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14
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Copilaş-Ciocianu D, Borko Š, Fišer C. The late blooming amphipods: Global change promoted post-Jurassic ecological radiation despite Palaeozoic origin. Mol Phylogenet Evol 2020; 143:106664. [DOI: 10.1016/j.ympev.2019.106664] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 10/19/2019] [Accepted: 10/24/2019] [Indexed: 01/04/2023]
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15
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Hughes DF, Blackburn DG. Evolutionary origins of viviparity in Chamaeleonidae. J ZOOL SYST EVOL RES 2019. [DOI: 10.1111/jzs.12328] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Daniel F. Hughes
- Department of Animal Sciences University of Illinois Urbana IL USA
| | - Daniel G. Blackburn
- Department of Biology, Electron Microscopy Center Trinity College Hartford CT USA
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16
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Back to the Future: Using Long-Term Observational and Paleo-Proxy Reconstructions to Improve Model Projections of Antarctic Climate. GEOSCIENCES 2019. [DOI: 10.3390/geosciences9060255] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Quantitative estimates of future Antarctic climate change are derived from numerical global climate models. Evaluation of the reliability of climate model projections involves many lines of evidence on past performance combined with knowledge of the processes that need to be represented. Routine model evaluation is mainly based on the modern observational period, which started with the establishment of a network of Antarctic weather stations in 1957/58. This period is too short to evaluate many fundamental aspects of the Antarctic and Southern Ocean climate system, such as decadal-to-century time-scale climate variability and trends. To help address this gap, we present a new evaluation of potential ways in which long-term observational and paleo-proxy reconstructions may be used, with a particular focus on improving projections. A wide range of data sources and time periods is included, ranging from ship observations of the early 20th century to ice core records spanning hundreds to hundreds of thousands of years to sediment records dating back 34 million years. We conclude that paleo-proxy records and long-term observational datasets are an underused resource in terms of strategies for improving Antarctic climate projections for the 21st century and beyond. We identify priorities and suggest next steps to addressing this.
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Thiemens MH, Lin M. Use of Isotope Effects To Understand the Present and Past of the Atmosphere and Climate and Track the Origin of Life. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201812322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mark H. Thiemens
- Department of Chemistry and BiochemistryUniversity of California San Diego La Jolla California 92093 USA
| | - Mang Lin
- Department of Chemistry and BiochemistryUniversity of California San Diego La Jolla California 92093 USA
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18
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Thiemens MH, Lin M. Use of Isotope Effects To Understand the Present and Past of the Atmosphere and Climate and Track the Origin of Life. Angew Chem Int Ed Engl 2019; 58:6826-6844. [PMID: 30633432 DOI: 10.1002/anie.201812322] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Indexed: 12/19/2022]
Abstract
Stable isotope ratio measurements have been used as a measure of a wide variety of processes, including solar system evolution, geological formational temperatures, tracking of atmospheric gas and aerosol chemical transformation, and is the only means by which past global temperatures may be determined over long time scales. Conventionally, isotope effects derive from differences of isotopically substituted molecules in isotope vibrational energy, bond strength, velocity, gravity, and evaporation/condensation. The variations in isotope ratio, such as 18 O/16 O (δ18 O) and 17 O/16 O (δ17 O) are dependent upon mass differences with δ17 O/δ18 O=0.5, due to the relative mass differences (1 amu vs. 2 amu). Relations that do not follow this are termed mass independent and are the focus of this Minireview. In chemical reactions such as ozone formation, a δ17 O/δ18 O=1 is observed. Physical chemical models capture most parameters but differ in basic approach and are reviewed. The mass independent effect is observed in atmospheric species and used to track their chemistry at the modern and ancient Earth, Mars, and the early solar system (meteorites).
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Affiliation(s)
- Mark H Thiemens
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, 92093, USA
| | - Mang Lin
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California, 92093, USA
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19
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González-Wevar CA, Hüne M, Rosenfeld S, Nakano T, Saucède T, Spencer H, Poulin E. Systematic revision of Nacella (Patellogastropoda: Nacellidae) based on a complete phylogeny of the genus, with the description of a new species from the southern tip of South America. Zool J Linn Soc 2018. [DOI: 10.1093/zoolinnean/zly067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Claudio A González-Wevar
- Laboratorio de Genómica y Ecología Molecular Antártica y sub-Antártica, Instituto de Ciencias Marinas y Limnológicas (ICML), Universidad Austral de Chile, Edificio Emilio Pugín, Campus Isla Teja, Valdivia, XIV Región de los Ríos, Chile
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Universidad de Chile, Las Palmeras #3425, Ñuñoa, Santiago, Chile
- Centro FONDAP de Investigaciones en Dinámica de Ecosistemas Marinos de Altas Latitudes, Universidad Austral de Chile, Chile
| | - Mathias Hüne
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Universidad de Chile, Las Palmeras #3425, Ñuñoa, Santiago, Chile
| | - Sebastián Rosenfeld
- Laboratorio de Ecosistemas Marinos Antárticos y Subantárticos, Universidad de Magallanes, Casilla, Punta Arenas, Chile
| | - Tomoyuki Nakano
- Seto Marine Biological Laboratory, Field Science Education and Research Centre, Kyoto University, Nishimuro, Wakayama, Japan
| | - Thomas Saucède
- IMBE-Institut Méditerranéen de Biologie et d’Ecologie marine et continentale, Station Marine d’Endoume, Marseille, France
| | - Hamish Spencer
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Elie Poulin
- Instituto de Ecología y Biodiversidad (IEB), Departamento de Ciencias Ecológicas, Universidad de Chile, Las Palmeras #3425, Ñuñoa, Santiago, Chile
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20
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Sheremetiev SN, Chebotareva KE. Modern and Cretaceous–Cenozoic Diversification of Angiosperms. ACTA ACUST UNITED AC 2018. [DOI: 10.1134/s2079086418050079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Geeza TJ, Gillikin DP, McDevitt B, Van Sice K, Warner NR. Accumulation of Marcellus Formation Oil and Gas Wastewater Metals in Freshwater Mussel Shells. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10883-10892. [PMID: 30179464 DOI: 10.1021/acs.est.8b02727] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
For several decades, high-salinity water brought to the surface during oil and gas (O&G) production has been treated and discharged to waterways under National Pollutant Discharge Elimination System (NPDES) permits. In Pennsylvania, USA, a portion of the treated O&G wastewater discharged to streams from 2008 to 2011 originated from unconventional (Marcellus) wells. We collected freshwater mussels, Elliptio dilatata and Elliptio complanata, both upstream and downstream of a NPDES-permitted facility, and for comparison, we also collected mussels from the Juniata and Delaware Rivers that have no reported O&G discharge. We observed changes in both the Sr/Cashell and 87Sr/86Srshell in shell samples collected downstream of the facility that corresponded to the time period of greatest Marcellus wastewater disposal (2009-2011). Importantly, the changes in Sr/Cashell and 87Sr/86Srshell shifted toward values characteristic of O&G wastewater produced from the Marcellus Formation. Conversely, shells collected upstream of the discharge and from waterways without treatment facilities showed lower variability and no trend in either Sr/Cashell or 87Sr/86Srshell with time (2008-2015). These findings suggest that (1) freshwater mussels may be used to monitor changes in water chemistry through time and help identify specific pollutant sources and (2) O&G contaminants likely bioaccumulated in areas of surface water disposal.
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Affiliation(s)
- Thomas J Geeza
- Department of Civil and Environmental Engineering , The Pennsylvania State University , 212 Sackett Building , University Park , Pennsylvania 16802 , United States
| | - David P Gillikin
- Department of Geology , Union College , 807 Union St , Schenectady , New York 12308 , United States
| | - Bonnie McDevitt
- Department of Civil and Environmental Engineering , The Pennsylvania State University , 212 Sackett Building , University Park , Pennsylvania 16802 , United States
| | - Katherine Van Sice
- Department of Civil and Environmental Engineering , The Pennsylvania State University , 212 Sackett Building , University Park , Pennsylvania 16802 , United States
| | - Nathaniel R Warner
- Department of Civil and Environmental Engineering , The Pennsylvania State University , 212 Sackett Building , University Park , Pennsylvania 16802 , United States
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22
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Cramwinckel MJ, Huber M, Kocken IJ, Agnini C, Bijl PK, Bohaty SM, Frieling J, Goldner A, Hilgen FJ, Kip EL, Peterse F, van der Ploeg R, Röhl U, Schouten S, Sluijs A. Synchronous tropical and polar temperature evolution in the Eocene. Nature 2018; 559:382-386. [PMID: 29967546 DOI: 10.1038/s41586-018-0272-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 04/13/2018] [Indexed: 11/09/2022]
Abstract
Palaeoclimate reconstructions of periods with warm climates and high atmospheric CO2 concentrations are crucial for developing better projections of future climate change. Deep-ocean1,2 and high-latitude3 palaeotemperature proxies demonstrate that the Eocene epoch (56 to 34 million years ago) encompasses the warmest interval of the past 66 million years, followed by cooling towards the eventual establishment of ice caps on Antarctica. Eocene polar warmth is well established, so the main obstacle in quantifying the evolution of key climate parameters, such as global average temperature change and its polar amplification, is the lack of continuous high-quality tropical temperature reconstructions. Here we present a continuous Eocene equatorial sea surface temperature record, based on biomarker palaeothermometry applied on Atlantic Ocean sediments. We combine this record with the sparse existing data4-6 to construct a 26-million-year multi-proxy, multi-site stack of Eocene tropical climate evolution. We find that tropical and deep-ocean temperatures changed in parallel, under the influence of both long-term climate trends and short-lived events. This is consistent with the hypothesis that greenhouse gas forcing7,8, rather than changes in ocean circulation9,10, was the main driver of Eocene climate. Moreover, we observe a strong linear relationship between tropical and deep-ocean temperatures, which implies a constant polar amplification factor throughout the generally ice-free Eocene. Quantitative comparison with fully coupled climate model simulations indicates that global average temperatures were about 29, 26, 23 and 19 degrees Celsius in the early, early middle, late middle and late Eocene, respectively, compared to the preindustrial temperature of 14.4 degrees Celsius. Finally, combining proxy- and model-based temperature estimates with available CO2 reconstructions8 yields estimates of an Eocene Earth system sensitivity of 0.9 to 2.3 kelvin per watt per square metre at 68 per cent probability, consistent with the high end of previous estimates11.
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Affiliation(s)
- Margot J Cramwinckel
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands.
| | - Matthew Huber
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, USA
| | - Ilja J Kocken
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands
| | - Claudia Agnini
- Department of Geosciences, University of Padova, Padova, Italy
| | - Peter K Bijl
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands
| | - Steven M Bohaty
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
| | - Joost Frieling
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands
| | - Aaron Goldner
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN, USA
| | - Frederik J Hilgen
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands
| | - Elizabeth L Kip
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands
| | - Francien Peterse
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands
| | - Robin van der Ploeg
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands
| | - Ursula Röhl
- MARUM - Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Stefan Schouten
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands.,NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Microbiology and Biogeochemistry and Utrecht University, Den Burg, The Netherlands
| | - Appy Sluijs
- Department of Earth Sciences, Faculty of Geoscience, Utrecht University, Utrecht, The Netherlands
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23
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Maisch HM, Becker MA, Chamberlain JA. Lamniform and Carcharhiniform Sharks from the Pungo River and Yorktown Formations (Miocene–Pliocene) of the Submerged Continental Shelf, Onslow Bay, North Carolina, USA. COPEIA 2018. [DOI: 10.1643/ot-18-016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Abstract
Earth’s modern climate is defined by the presence of ice at both poles, but that ice is now disappearing. Therefore understanding the origin and causes of polar ice stability is more critical than ever. Here we provide novel geochemical data that constrain past dynamics of glacial ice on Greenland and Arctic sea ice. Based on accurate source determinations of individual ice-rafted Fe-oxide grains, we find evidence for episodic glaciation of distinct source regions on Greenland as far-ranging as ~68°N and ~80°N synchronous with ice-rafting from circum-Arctic sources, beginning in the middle Eocene. Glacial intervals broadly coincide with reduced CO2, with a potential threshold for glacial ice stability near ~500 p.p.m.v. The middle Eocene represents the Cenozoic onset of a dynamic cryosphere, with ice in both hemispheres during transient glacials and substantial regional climate heterogeneity. A more stable cryosphere developed at the Eocene-Oligocene transition, and is now threatened by anthropogenic emissions. With rapidly disappearing ice, understanding the past behavior of the cryosphere is critical. Here, the authors indicate the initiation and disappearance of glaciation on Greenland and Arctic sea ice coincided in the past, synchronous with Antarctic ice and global ice volume, and a CO2 threshold of ~500 p.p.m.v.
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Müller RD, Dutkiewicz A. Oceanic crustal carbon cycle drives 26-million-year atmospheric carbon dioxide periodicities. SCIENCE ADVANCES 2018; 4:eaaq0500. [PMID: 29457135 PMCID: PMC5812735 DOI: 10.1126/sciadv.aaq0500] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/16/2018] [Indexed: 06/08/2023]
Abstract
Atmospheric carbon dioxide (CO2) data for the last 420 million years (My) show long-term fluctuations related to supercontinent cycles as well as shorter cycles at 26 to 32 My whose origin is unknown. Periodicities of 26 to 30 My occur in diverse geological phenomena including mass extinctions, flood basalt volcanism, ocean anoxic events, deposition of massive evaporites, sequence boundaries, and orogenic events and have previously been linked to an extraterrestrial mechanism. The vast oceanic crustal carbon reservoir is an alternative potential driving force of climate fluctuations at these time scales, with hydrothermal crustal carbon uptake occurring mostly in young crust with a strong dependence on ocean bottom water temperature. We combine a global plate model and oceanic paleo-age grids with estimates of paleo-ocean bottom water temperatures to track the evolution of the oceanic crustal carbon reservoir over the past 230 My. We show that seafloor spreading rates as well as the storage, subduction, and emission of oceanic crustal and mantle CO2 fluctuate with a period of 26 My. A connection with seafloor spreading rates and equivalent cycles in subduction zone rollback suggests that these periodicities are driven by the dynamics of subduction zone migration. The oceanic crust-mantle carbon cycle is thus a previously overlooked mechanism that connects plate tectonic pulsing with fluctuations in atmospheric carbon and surface environments.
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Affiliation(s)
- R. Dietmar Müller
- EarthByte Group, School of Geosciences, University of Sydney, Sydney, New South Wales 2006, Australia
- Sydney Informatics Hub, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Adriana Dutkiewicz
- EarthByte Group, School of Geosciences, University of Sydney, Sydney, New South Wales 2006, Australia
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Pérez-Díaz L, Eagles G. South Atlantic paleobathymetry since early Cretaceous. Sci Rep 2017; 7:11819. [PMID: 28924144 PMCID: PMC5603583 DOI: 10.1038/s41598-017-11959-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 09/01/2017] [Indexed: 12/05/2022] Open
Abstract
We present early Cretaceous to present paleobathymetric reconstructions and quantitative uncertainty estimates for the South Atlantic, offering a strong basis for studies of paleocirculation, paleoclimate and paleobiogeography. Circulation in an initially salty and anoxic ocean, restricted by the topography of the Falkland Plateau, Rio Grande Ridge and Walvis Rise, favoured deposition of thick evaporites in shallow water of the Brazilian-Angolan margins. This ceased as seafloor spreading propagated northwards, opening an equatorial gateway to shallow and intermediate circulation. This gateway, together with subsiding volcano-tectonic barriers would have played a key role in Late Cretaceous climate changes. Later deepening and widening of the South Atlantic, together with gateway opening at Drake Passage would lead, by mid-Miocene (∼15 Ma) to the establishment of modern-style thermohaline circulation.
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Affiliation(s)
- Lucía Pérez-Díaz
- Royal Holloway University of London, TW20 0EX, Egham, Surrey, UK.
| | - Graeme Eagles
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Alten Hafen 26, 27568, Bremerhaven, Germany
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Abstract
Clumped isotopes geochemistry measures the thermodynamic preference of two heavy, rare, isotopes to bind with each other. This preference is temperature dependent, and is more pronounced at low temperatures. Carbonate clumped isotope values are independent of the carbonate δ13C and δ18O, making them independent of the carbon or oxygen composition of the solution from which the carbonate precipitated. At equilibrium, it is therefore a direct proxy for the temperature in which the carbonate mineral formed. In most cases, carbonate clumped isotopes record the temperature of carbonate formation, irrespective of the mineral form (calcite, aragonite, or bioapatite) or the organism making it. The carbonate formation temperatures obtained from carbonate clumped isotope analysis can be used in conjunction with the δ18O of the same carbonate, to constrain the oxygen isotope composition of the water from which the carbonate has precipitated. There are, however, cases of deviation from thermodynamic equilibrium, where both clumped and oxygen isotopes are offset from the expected values. Such carbonates must be characterized and calibrated separately. For deep-time applications, special care must be paid to the preservation of the original signal, in particular with respect to diagenetic alteration associated with atomic scale diffusion that may be undetectable by common tests for diagenesis.
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Abstract
Foraminiferal tests are a common component of many marine sediments. The oxygen isotope ratio (δ18O) of test calcite is frequently used to reconstruct aspects of their life environment. The δ18O depends mainly on the isotope ratio of the water it is precipitated from, the temperature of calcification, and, to a lesser extent, the carbonate ion concentration. Foraminifera and other organisms can potentially preserve their original isotope ratio for many millions of years, although diagenetic processes can alter the ratios. Work on oxygen isotope ratios of foraminifera was instrumental in the discovery of the orbital theory of the ice ages and continues to be widely used in the study of rapid climate change. Compilations of deep sea benthic foraminifer oxygen isotopes have revealed the long history of global climate change over the past 100 million years. Planktonic foraminifer oxygen isotopes are used to investigate the history of past sea surface temperatures, revealing the extent of past ‘greenhouse’ warming and global sea surface temperatures.
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Verheye ML, Backeljau T, d'Udekem d'Acoz C. Locked in the icehouse: Evolution of an endemic Epimeria (Amphipoda, Crustacea) species flock on the Antarctic shelf. Mol Phylogenet Evol 2017; 114:14-33. [PMID: 28528744 DOI: 10.1016/j.ympev.2017.05.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 05/12/2017] [Accepted: 05/14/2017] [Indexed: 11/24/2022]
Abstract
The Antarctic shelf's marine biodiversity has been greatly influenced by the climatic and glacial history of the region. Extreme temperature changes led to the extinction of some lineages, while others adapted and flourished. The amphipod genus Epimeria is an example of the latter, being particularly diverse in the Antarctic region. By reconstructing a time-calibrated phylogeny based on mitochondrial (COI) and nuclear (28S and H3) markers and including Epimeria species from all oceans, this study provides a temporal and geographical framework for the evolution of Antarctic Epimeria. The monophyly of this genus is not supported by Bayesian Inference, as Antarctic and non-Antarctic Epimeria form two distinct well-supported clades, with Antarctic Epimeria being a sister clade to two stilipedid species. The monophyly of Antarctic Epimeria suggests that this clade evolved in isolation since its origin. While the precise timing of this origin remains unclear, it is inferred that the Antarctic lineage arose from a late Gondwanan ancestor and hence did not colonize the Antarctic region after the continent broke apart from the other fragments of Gondwanaland. The initial diversification of the clade occurred 38.04Ma (95% HPD [48.46Ma; 28.36Ma]) in a cooling environment. Adaptation to cold waters, along with the extinction of cold-intolerant taxa and resulting ecological opportunities, likely led to the successful diversification of Epimeria on the Antarctic shelf. However, there was neither evidence of a rapid lineage diversification early in the clade's history, nor of any shifts in diversification rates induced by glacial cycles. This suggests that a high turnover rate on the repeatedly scoured Antarctic shelf could have masked potential signals of diversification bursts.
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Affiliation(s)
- Marie L Verheye
- Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny, rue Vautier 29, 1000 Brussels, Belgium; Catholic University of Louvain-la-Neuve, Department of Biology, Marine Biology Laboratory, Croix du Sud 3 bte L7.06.04, 1348 Louvain-la-Neuve, Belgium.
| | - Thierry Backeljau
- Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny, rue Vautier 29, 1000 Brussels, Belgium; University of Antwerp, Evolutionary Ecology Group, Universiteitsplein 1, 2160 Antwerp, Belgium
| | - Cédric d'Udekem d'Acoz
- Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny, rue Vautier 29, 1000 Brussels, Belgium
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Stolper DA, Bender ML, Dreyfus GB, Yan Y, Higgins JA. A Pleistocene ice core record of atmospheric O2 concentrations. Science 2017; 353:1427-1430. [PMID: 27708037 DOI: 10.1126/science.aaf5445] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 08/02/2016] [Indexed: 11/02/2022]
Abstract
The history of atmospheric O2 partial pressures (Po2) is inextricably linked to the coevolution of life and Earth's biogeochemical cycles. Reconstructions of past Po2 rely on models and proxies but often markedly disagree. We present a record of Po2 reconstructed using O2/N2 ratios from ancient air trapped in ice. This record indicates that Po2 declined by 7 per mil (0.7%) over the past 800,000 years, requiring that O2 sinks were ~2% larger than sources. This decline is consistent with changes in burial and weathering fluxes of organic carbon and pyrite driven by either Neogene cooling or increasing Pleistocene erosion rates. The 800,000-year record of steady average carbon dioxide partial pressures (Pco2) but declining Po2 provides distinctive evidence that a silicate weathering feedback stabilizes Pco2 on million-year time scales.
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Affiliation(s)
- D A Stolper
- Department of Geosciences, Princeton University, Princeton, NJ 08544, USA
| | - M L Bender
- Department of Geosciences, Princeton University, Princeton, NJ 08544, USA. Institute of Oceanology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - G B Dreyfus
- Department of Geosciences, Princeton University, Princeton, NJ 08544, USA. Laboratoire des Sciences du Climat et de l'Environnement, Gif-sur-Yvettte, France
| | - Y Yan
- Department of Geosciences, Princeton University, Princeton, NJ 08544, USA
| | - J A Higgins
- Department of Geosciences, Princeton University, Princeton, NJ 08544, USA
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Equatorial heat accumulation as a long-term trigger of permanent Antarctic ice sheets during the Cenozoic. Proc Natl Acad Sci U S A 2016; 113:11782-11787. [PMID: 27698116 DOI: 10.1073/pnas.1608100113] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Growth of the first permanent Antarctic ice sheets at the Eocene-Oligocene Transition (EOT), ∼33.7 million years ago, indicates a major climate shift within long-term Cenozoic cooling. The driving mechanisms that set the stage for this glaciation event are not well constrained, however, owing to large uncertainties in temperature reconstructions during the Eocene, especially at lower latitudes. To address this deficiency, we used recent developments in coccolith biogeochemistry to reconstruct equatorial Atlantic sea surface temperature (SST) and atmospheric pCO2 values from pelagic sequences preceding and spanning the EOT. We found significantly more variability in equatorial SSTs than previously reported, with pronounced cooling from the Early to Middle Eocene and subsequent warming during the Late Eocene. Thus, we show that the Antarctic glaciation at the Eocene-Oligocene boundary was preceded by a period of heat accumulation in the low latitudes, likely focused in a progressively contracting South Atlantic gyre, which contributed to cooling high-latitude austral regions. This prominent redistribution of heat corresponds to the emplacement of a strong meridional temperature gradient that typifies icehouse climate conditions. Our equatorial coccolith-derived geochemical record thus highlights an important period of global climatic and oceanic upheaval, which began 4 million years before the EOT and, superimposed on a long-term pCO2 decline, drove the Earth system toward a glacial tipping point in the Cenozoic.
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Hyeong K, Kuroda J, Seo I, Wilson PA. Response of the Pacific inter-tropical convergence zone to global cooling and initiation of Antarctic glaciation across the Eocene Oligocene Transition. Sci Rep 2016; 6:30647. [PMID: 27507793 PMCID: PMC4979033 DOI: 10.1038/srep30647] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 07/08/2016] [Indexed: 11/10/2022] Open
Abstract
Approximately 34 million years ago across the Eocene–Oligocene transition (EOT), Earth’s climate tipped from a largely unglaciated state into one that sustained large ice sheets on Antarctica. Antarctic glaciation is attributed to a threshold response to slow decline in atmospheric CO2 but our understanding of the feedback processes triggered and of climate change on the other contents is limited. Here we present new geochemical records of terrigenous dust accumulating on the sea floor across the EOT from a site in the central equatorial Pacific. We report a change in dust chemistry from an Asian affinity to a Central-South American provenance that occurs geologically synchronously with the initiation of stepwise global cooling, glaciation of Antarctica and aridification on the northern continents. We infer that the inter-tropical convergence zone of intense precipitation extended to our site during late Eocene, at least four degrees latitude further south than today, but that it migrated northwards in step with global cooling and initiation of Antarctic glaciation. Our findings point to an atmospheric teleconnection between extratropical cooling and rainfall climate in the tropics and the mid-latitude belt of the westerlies operating across the most pivotal transition in climate state of the Cenozoic Era.
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Affiliation(s)
- Kiseong Hyeong
- Korea Institute of Ocean Science and Technology, Ansan, South Korea
| | - Junichiro Kuroda
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Inah Seo
- Korea Institute of Ocean Science and Technology, Ansan, South Korea.,School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea
| | - Paul A Wilson
- National Oceanography Center Southampton, University of Southampton, Waterfront Campus, Southampton, SO14 3ZH, UK
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Changing atmospheric CO2 concentration was the primary driver of early Cenozoic climate. Nature 2016; 533:380-4. [PMID: 27111509 DOI: 10.1038/nature17423] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 02/10/2016] [Indexed: 11/08/2022]
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Deng T, Ding L. Paleoaltimetry reconstructions of the Tibetan Plateau: progress and contradictions. Natl Sci Rev 2015. [DOI: 10.1093/nsr/nwv062] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Over the last two decades, many quantitative paleoaltimetry reconstructions of the Tibetan Plateau have been published, but they are still preliminary and controversial, although several approaches have been combined paleontology and geochemistry, including vertebrate, plant, and pollen fossils as well as oxygen, carbon, and hydrogen isotopes. The Tibetan Plateau is the youngest and highest plateau on Earth, and its paleoaltimetry reconstructions are crucial to interpret its geodynamic evolution and to understand the climatic changes in Asia. Uplift histories of the Tibetan Plateau based on different proxies differ considerably, and two viewpoints are pointedly opposing on the paleoaltimetry estimations of the Tibetan Plateau. One viewpoint is that the Tibetan Plateau did not strongly uplift to reach its modern elevation until the Late Miocene, but another one, mainly based on stable isotopes, argues that the Tibetan Plateau formed early during the Indo-Asian collision and reached its modern elevation in the Paleogene or by the Middle Miocene. With either a geochemical or paleontological approach, the present is used as the key to the past. However, there are great difficulties because modern processes of isotopic fractionation and species for creature distribution are not easily precisely determined. In addition, the climatic and environmental backgrounds of past geological times have massive differences from the present, and associated adjustments are influenced by many human factors. In the future work, the applications of multidisciplinary comprehensive methods and cross-checks of their results will be productive, and we look forward to achieving more reliable estimates for paleoelevations of the Tibetan Plateau.
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Affiliation(s)
- Tao Deng
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
| | - Lin Ding
- Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China
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Yasuhara M, Danovaro R. Temperature impacts on deep-sea biodiversity. Biol Rev Camb Philos Soc 2014; 91:275-87. [PMID: 25523624 DOI: 10.1111/brv.12169] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 11/19/2014] [Accepted: 11/21/2014] [Indexed: 10/24/2022]
Abstract
Temperature is considered to be a fundamental factor controlling biodiversity in marine ecosystems, but precisely what role temperature plays in modulating diversity is still not clear. The deep ocean, lacking light and in situ photosynthetic primary production, is an ideal model system to test the effects of temperature changes on biodiversity. Here we synthesize current knowledge on temperature-diversity relationships in the deep sea. Our results from both present and past deep-sea assemblages suggest that, when a wide range of deep-sea bottom-water temperatures is considered, a unimodal relationship exists between temperature and diversity (that may be right skewed). It is possible that temperature is important only when at relatively high and low levels but does not play a major role in the intermediate temperature range. Possible mechanisms explaining the temperature-biodiversity relationship include the physiological-tolerance hypothesis, the metabolic hypothesis, island biogeography theory, or some combination of these. The possible unimodal relationship discussed here may allow us to identify tipping points at which on-going global change and deep-water warming may increase or decrease deep-sea biodiversity. Predicted changes in deep-sea temperatures due to human-induced climate change may have more adverse consequences than expected considering the sensitivity of deep-sea ecosystems to temperature changes.
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Affiliation(s)
- Moriaki Yasuhara
- School of Biological Sciences, Swire Institute of Marine Science, and Department of Earth Sciences, The University of Hong Kong, Hong Kong, China
| | - Roberto Danovaro
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy.,Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
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36
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Sun J, Ni X, Bi S, Wu W, Ye J, Meng J, Windley BF. Synchronous turnover of flora, fauna, and climate at the Eocene-Oligocene Boundary in Asia. Sci Rep 2014; 4:7463. [PMID: 25501388 PMCID: PMC4264005 DOI: 10.1038/srep07463] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 11/25/2014] [Indexed: 01/31/2023] Open
Abstract
The Eocene–Oligocene Boundary (~34 million years ago) marks one of the largest extinctions of marine invertebrates in the world oceans and of mammalian fauna in Europe and Asia in the Cenozoic era. A shift to a cooler climate across this boundary has been suggested as the cause of this extinction in the marine environment, but there is no manifold evidence for a synchronous turnover of flora, fauna and climate at the Eocene–Oligocene Boundary in a single terrestrial site in Asia to support this hypothesis. Here we report new data of magnetostratigraphy, pollen and climatic proxies in the Asian interior across the Eocene–Oligocene Boundary; our results show that climate change forced a turnover of flora and fauna, suggesting there was a change from large-size perissodactyl-dominant fauna in forests under a warm-temperate climate to small rodent/lagomorph-dominant fauna in forest-steppe in a dry-temperate climate across the Eocene–Oligocene Boundary. These data provide a new terrestrial record for this significant Cenozoic environmental event.
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Affiliation(s)
- Jimin Sun
- 1] Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China [2] CAS Center for Excellence in Tibetan Plateau Earth Sciences
| | - Xijun Ni
- Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Shundong Bi
- Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Wenyu Wu
- Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Jie Ye
- Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Jin Meng
- 1] Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China [2] American Museum of Natural History, New York, New York 10024, USA
| | - Brian F Windley
- Department of Geology, University of Leicester, Leicester LEI 7RH, UK
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González-Wevar CA, Chown SL, Morley S, Coria N, Saucéde T, Poulin E. Out of Antarctica: quaternary colonization of sub-Antarctic Marion Island by the limpet genus Nacella (Patellogastropoda: Nacellidae). Polar Biol 2014. [DOI: 10.1007/s00300-014-1620-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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38
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Low level of genetic divergence between Harpagifer fish species (Perciformes: Notothenioidei) suggests a Quaternary colonization of Patagonia from the Antarctic Peninsula. Polar Biol 2014. [DOI: 10.1007/s00300-014-1623-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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39
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Kiel S, Glodny J, Birgel D, Bulot LG, Campbell KA, Gaillard C, Graziano R, Kaim A, Lazăr I, Sandy MR, Peckmann J. The paleoecology, habitats, and stratigraphic range of the enigmatic cretaceous brachiopod peregrinella. PLoS One 2014; 9:e109260. [PMID: 25296341 PMCID: PMC4190153 DOI: 10.1371/journal.pone.0109260] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 09/03/2014] [Indexed: 11/19/2022] Open
Abstract
Modern and Cenozoic deep-sea hydrothermal-vent and methane-seep communities are dominated by large tubeworms, bivalves and gastropods. In contrast, many Early Cretaceous seep communities were dominated by the largest Mesozoic rhynchonellid brachiopod, the dimerelloid Peregrinella, the paleoecologic and evolutionary traits of which are still poorly understood. We investigated the nature of Peregrinella based on 11 occurrences world wide and a literature survey. All in situ occurrences of Peregrinella were confirmed as methane-seep deposits, supporting the view that Peregrinella lived exclusively at methane seeps. Strontium isotope stratigraphy indicates that Peregrinella originated in the late Berriasian and disappeared after the early Hauterivian, giving it a geologic range of ca. 9.0 (+1.45/–0.85) million years. This range is similar to that of rhynchonellid brachiopod genera in general, and in this respect Peregrinella differs from seep-inhabiting mollusks, which have, on average, longer geologic ranges than marine mollusks in general. Furthermore, we found that (1) Peregrinella grew to larger sizes at passive continental margins than at active margins; (2) it grew to larger sizes at sites with diffusive seepage than at sites with advective fluid flow; (3) despite its commonly huge numerical abundance, its presence had no discernible impact on the diversity of other taxa at seep sites, including infaunal chemosymbiotic bivalves; and (4) neither its appearance nor its extinction coincides with those of other seep-restricted taxa or with global extinction events during the late Mesozoic. A preference of Peregrinella for diffusive seepage is inferred from the larger average sizes of Peregrinella at sites with more microcrystalline carbonate (micrite) and less seep cements. Because other seep-inhabiting brachiopods occur at sites where such cements are very abundant, we speculate that the various vent- and seep-inhabiting dimerelloid brachiopods since Devonian time may have adapted to these environments in more than one way.
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Affiliation(s)
- Steffen Kiel
- Georg-August-Universität Göttingen, Geowissenschaftliches Zentrum, Abteilung Geobiologie, Göttingen, Germany
- * E-mail:
| | - Johannes Glodny
- Deutsches GeoForschungsZentrum GFZ, Sektion 4.2, Anorganische und Isotopengeochemie, Telegrafenberg, Potsdam, Germany
| | - Daniel Birgel
- Universität Wien, Erdwissenschaftliches Zentrum, Department für Geodynamik und Sedimentologie, Wien, Austria
| | - Luc G. Bulot
- FRE CNRS 2761, Centre de Sédimentologie-Paléontologie, Université de Provence, Marseille, France
| | - Kathleen A. Campbell
- University of Auckland, Geology Programme, School of Environment Science, Auckland, New Zealand
| | - Christian Gaillard
- Université de Lyon-1, UMR CNRS 5125 Paléoenvironnements et Paléobiosphère, Villeurbanne, France
| | - Roberto Graziano
- Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse, Università di Napoli Federico II, Largo S. Marcellino, Napoli, Italia
| | | | - Iuliana Lazăr
- University of Bucharest, Faculty of Geology and Geophysics, Department of Geology, Bucharest, Romania
| | - Michael R. Sandy
- University of Dayton, Department of Geology, Dayton, Ohio, United States of America
| | - Jörn Peckmann
- Universität Wien, Erdwissenschaftliches Zentrum, Department für Geodynamik und Sedimentologie, Wien, Austria
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40
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Brown A, Thatje S. Explaining bathymetric diversity patterns in marine benthic invertebrates and demersal fishes: physiological contributions to adaptation of life at depth. Biol Rev Camb Philos Soc 2014; 89:406-26. [PMID: 24118851 PMCID: PMC4158864 DOI: 10.1111/brv.12061] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 08/01/2013] [Accepted: 08/14/2013] [Indexed: 12/01/2022]
Abstract
Bathymetric biodiversity patterns of marine benthic invertebrates and demersal fishes have been identified in the extant fauna of the deep continental margins. Depth zonation is widespread and evident through a transition between shelf and slope fauna from the shelf break to 1000 m, and a transition between slope and abyssal fauna from 2000 to 3000 m; these transitions are characterised by high species turnover. A unimodal pattern of diversity with depth peaks between 1000 and 3000 m, despite the relatively low area represented by these depths. Zonation is thought to result from the colonisation of the deep sea by shallow-water organisms following multiple mass extinction events throughout the Phanerozoic. The effects of low temperature and high pressure act across hierarchical levels of biological organisation and appear sufficient to limit the distributions of such shallow-water species. Hydrostatic pressures of bathyal depths have consistently been identified experimentally as the maximum tolerated by shallow-water and upper bathyal benthic invertebrates at in situ temperatures, and adaptation appears required for passage to deeper water in both benthic invertebrates and demersal fishes. Together, this suggests that a hyperbaric and thermal physiological bottleneck at bathyal depths contributes to bathymetric zonation. The peak of the unimodal diversity-depth pattern typically occurs at these depths even though the area represented by these depths is relatively low. Although it is recognised that, over long evolutionary time scales, shallow-water diversity patterns are driven by speciation, little consideration has been given to the potential implications for species distribution patterns with depth. Molecular and morphological evidence indicates that cool bathyal waters are the primary site of adaptive radiation in the deep sea, and we hypothesise that bathymetric variation in speciation rates could drive the unimodal diversity-depth pattern over time. Thermal effects on metabolic-rate-dependent mutation and on generation times have been proposed to drive differences in speciation rates, which result in modern latitudinal biodiversity patterns over time. Clearly, this thermal mechanism alone cannot explain bathymetric patterns since temperature generally decreases with depth. We hypothesise that demonstrated physiological effects of high hydrostatic pressure and low temperature at bathyal depths, acting on shallow-water taxa invading the deep sea, may invoke a stress-evolution mechanism by increasing mutagenic activity in germ cells, by inactivating canalisation during embryonic or larval development, by releasing hidden variation or mutagenic activity, or by activating or releasing transposable elements in larvae or adults. In this scenario, increased variation at a physiological bottleneck at bathyal depths results in elevated speciation rate. Adaptation that increases tolerance to high hydrostatic pressure and low temperature allows colonisation of abyssal depths and reduces the stress-evolution response, consequently returning speciation of deeper taxa to the background rate. Over time this mechanism could contribute to the unimodal diversity-depth pattern.
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Affiliation(s)
- Alastair Brown
- Ocean and Earth Science, University of Southampton, National Oceanography Centre SouthamptonEuropean Way, Southampton, SO14 3ZH, U.K.
| | - Sven Thatje
- Ocean and Earth Science, University of Southampton, National Oceanography Centre SouthamptonEuropean Way, Southampton, SO14 3ZH, U.K.
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Dowsett HJ, Robinson MM, Stoll DK, Foley KM, Johnson ALA, Williams M, Riesselman CR. The PRISM (Pliocene palaeoclimate) reconstruction: time for a paradigm shift. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2013; 371:20120524. [PMID: 24043866 DOI: 10.1098/rsta.2012.0524] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Global palaeoclimate reconstructions have been invaluable to our understanding of the causes and effects of climate change, but single-temperature representations of the oceanic mixed layer for data-model comparisons are outdated, and the time for a paradigm shift in marine palaeoclimate reconstruction is overdue. The new paradigm in marine palaeoclimate reconstruction stems the loss of valuable climate information and instead presents a holistic and nuanced interpretation of multi-dimensional oceanographic processes and responses. A wealth of environmental information is hidden within the US Geological Survey's Pliocene Research, Interpretation and Synoptic Mapping (PRISM) marine palaeoclimate reconstruction, and we introduce here a plan to incorporate all valuable climate data into the next generation of PRISM products. Beyond the global approach and focus, we plan to incorporate regional climate dynamics with emphasis on processes, integrating multiple environmental proxies wherever available in order to better characterize the mixed layer, and developing a finer time slice within the Mid-Piacenzian Age of the Pliocene, complemented by underused proxies that offer snapshots into environmental conditions. The result will be a proxy-rich, temporally nested, process-oriented approach in a digital format-a relational database with geographic information system capabilities comprising a three-dimensional grid representing the surface layer, with a plethora of data in each cell.
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Affiliation(s)
- Harry J Dowsett
- Eastern Geology and Paleoclimate Science Center, US Geological Survey, Reston, VA 20192, USA
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42
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Hansen J, Sato M, Russell G, Kharecha P. Climate sensitivity, sea level and atmospheric carbon dioxide. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2013; 371:20120294. [PMID: 24043864 PMCID: PMC3785813 DOI: 10.1098/rsta.2012.0294] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Cenozoic temperature, sea level and CO2 covariations provide insights into climate sensitivity to external forcings and sea-level sensitivity to climate change. Climate sensitivity depends on the initial climate state, but potentially can be accurately inferred from precise palaeoclimate data. Pleistocene climate oscillations yield a fast-feedback climate sensitivity of 3±1(°)C for a 4 W m(-2) CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective because of poorly defined LGM global temperature and possible human influences in the Holocene. Glacial-to-interglacial climate change leading to the prior (Eemian) interglacial is less ambiguous and implies a sensitivity in the upper part of the above range, i.e. 3-4(°)C for a 4 W m(-2) CO2 forcing. Slow feedbacks, especially change of ice sheet size and atmospheric CO2, amplify the total Earth system sensitivity by an amount that depends on the time scale considered. Ice sheet response time is poorly defined, but we show that the slow response and hysteresis in prevailing ice sheet models are exaggerated. We use a global model, simplified to essential processes, to investigate state dependence of climate sensitivity, finding an increased sensitivity towards warmer climates, as low cloud cover is diminished and increased water vapour elevates the tropopause. Burning all fossil fuels, we conclude, would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change.
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Affiliation(s)
- James Hansen
- The Earth Institute, Columbia University, New York, NY 10027, USA
- e-mail:
| | - Makiko Sato
- The Earth Institute, Columbia University, New York, NY 10027, USA
| | - Gary Russell
- NASA Goddard Institute for Space Studies, New York, NY 10027, USA
| | - Pushker Kharecha
- The Earth Institute, Columbia University, New York, NY 10027, USA
- NASA Goddard Institute for Space Studies, New York, NY 10027, USA
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43
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Williams ST, Smith LM, Herbert DG, Marshall BA, Warén A, Kiel S, Dyal P, Linse K, Vilvens C, Kano Y. Cenozoic climate change and diversification on the continental shelf and slope: evolution of gastropod diversity in the family Solariellidae (Trochoidea). Ecol Evol 2013; 3:887-917. [PMID: 23610633 PMCID: PMC3631403 DOI: 10.1002/ece3.513] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 01/30/2013] [Accepted: 02/01/2013] [Indexed: 11/11/2022] Open
Abstract
Recent expeditions have revealed high levels of biodiversity in the tropical deep-sea, yet little is known about the age or origin of this biodiversity, and large-scale molecular studies are still few in number. In this study, we had access to the largest number of solariellid gastropods ever collected for molecular studies, including many rare and unusual taxa. We used a Bayesian chronogram of these deep-sea gastropods (1) to test the hypothesis that deep-water communities arose onshore, (2) to determine whether Antarctica acted as a source of diversity for deep-water communities elsewhere and (3) to determine how factors like global climate change have affected evolution on the continental slope. We show that although fossil data suggest that solariellid gastropods likely arose in a shallow, tropical environment, interpretation of the molecular data is equivocal with respect to the origin of the group. On the other hand, the molecular data clearly show that Antarctic species sampled represent a recent invasion, rather than a relictual ancestral lineage. We also show that an abrupt period of global warming during the Palaeocene Eocene Thermal Maximum (PETM) leaves no molecular record of change in diversification rate in solariellids and that the group radiated before the PETM. Conversely, there is a substantial, although not significant increase in the rate of diversification of a major clade approximately 33.7 Mya, coinciding with a period of global cooling at the Eocene-Oligocene transition. Increased nutrients made available by contemporaneous changes to erosion, ocean circulation, tectonic events and upwelling may explain increased diversification, suggesting that food availability may have been a factor limiting exploitation of deep-sea habitats. Tectonic events that shaped diversification in reef-associated taxa and deep-water squat lobsters in central Indo-West Pacific were also probably important in the evolution of solariellids during the Oligo-Miocene.
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Affiliation(s)
- S T Williams
- Department of Life Sciences, Natural History Museum Cromwell Road, London, SW7 5BD, UK
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Pross J, Contreras L, Bijl PK, Greenwood DR, Bohaty SM, Schouten S, Bendle JA, Röhl U, Tauxe L, Raine JI, Huck CE, van de Flierdt T, Jamieson SSR, Stickley CE, van de Schootbrugge B, Escutia C, Brinkhuis H. Persistent near-tropical warmth on the Antarctic continent during the early Eocene epoch. Nature 2012; 488:73-7. [PMID: 22859204 DOI: 10.1038/nature11300] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 06/08/2012] [Indexed: 11/09/2022]
Abstract
The warmest global climates of the past 65 million years occurred during the early Eocene epoch (about 55 to 48 million years ago), when the Equator-to-pole temperature gradients were much smaller than today and atmospheric carbon dioxide levels were in excess of one thousand parts per million by volume. Recently the early Eocene has received considerable interest because it may provide insight into the response of Earth's climate and biosphere to the high atmospheric carbon dioxide levels that are expected in the near future as a consequence of unabated anthropogenic carbon emissions. Climatic conditions of the early Eocene 'greenhouse world', however, are poorly constrained in critical regions, particularly Antarctica. Here we present a well-dated record of early Eocene climate on Antarctica from an ocean sediment core recovered off the Wilkes Land coast of East Antarctica. The information from biotic climate proxies (pollen and spores) and independent organic geochemical climate proxies (indices based on branched tetraether lipids) yields quantitative, seasonal temperature reconstructions for the early Eocene greenhouse world on Antarctica. We show that the climate in lowland settings along the Wilkes Land coast (at a palaeolatitude of about 70° south) supported the growth of highly diverse, near-tropical forests characterized by mesothermal to megathermal floral elements including palms and Bombacoideae. Notably, winters were extremely mild (warmer than 10 °C) and essentially frost-free despite polar darkness, which provides a critical new constraint for the validation of climate models and for understanding the response of high-latitude terrestrial ecosystems to increased carbon dioxide forcing.
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Affiliation(s)
- Jörg Pross
- Paleoenvironmental Dynamics Group, Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt, Germany.
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Barco A, Schiaparelli S, Houart R, Oliverio M. Cenozoic evolution of Muricidae (Mollusca, Neogastropoda) in the Southern Ocean, with the description of a new subfamily. ZOOL SCR 2012. [DOI: 10.1111/j.1463-6409.2012.00554.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Carbon isotopic record of terrestrial ecosystems spanning the Late Miocene extinction of Oreopithecus bambolii, Baccinello Basin (Tuscany, Italy). J Hum Evol 2012; 63:127-39. [DOI: 10.1016/j.jhevol.2012.04.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 04/20/2012] [Accepted: 04/24/2012] [Indexed: 11/20/2022]
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Cramer BS, Miller KG, Barrett PJ, Wright JD. Late Cretaceous–Neogene trends in deep ocean temperature and continental ice volume: Reconciling records of benthic foraminiferal geochemistry (δ18O and Mg/Ca) with sea level history. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jc007255] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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48
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Coggon RM, Teagle DA. Hydrothermal calcium-carbonate veins reveal past ocean chemistry. Trends Analyt Chem 2011. [DOI: 10.1016/j.trac.2011.02.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Bergue CT, Govindan A. Eocene-Pliocene deep sea ostracodes from ODP site 744A, Southern Indian Ocean. AN ACAD BRAS CIENC 2011; 82:747-60. [PMID: 21562702 DOI: 10.1590/s0001-37652010000300021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Accepted: 04/14/2010] [Indexed: 11/21/2022] Open
Abstract
The Eocene-Pliocene deep sea ostracodes from the ODP site 744A (Kerguelen Plateau) are herein studied under the taxonomic and paleoecologic aspects. 28 species are identified, being the genera Krithe, Cytherella and Dutoitella the most diversified. A faunal threshold was recorded in the Early Oligocene, which is tentatively explained under the knowledge of the paleoceanographical studies carried out not only in the Kerguelen Plateau but also in adjacent areas. The faunal turnover and variations in both richness and abundance possibly reflect the inception of psychrosphere and the influence of hydrological changes in the preservation of carapaces. Moreover, the influence of those changes on carbonate preservation is discussed as the cause of faunal impoverishment in the upper portion of the core.
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Affiliation(s)
- Cristianini T Bergue
- Universidade do Vale do Rio dos Sinos, Laboratório de Micropaleontologia, São Leopoldo, RS, Brazil.
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Clementz MT, Sewall JO. Latitudinal Gradients in Greenhouse Seawater 18O: Evidence from Eocene Sirenian Tooth Enamel. Science 2011; 332:455-8. [DOI: 10.1126/science.1201182] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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