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Coiro M, McLoughlin S, Steinthorsdottir M, Vajda V, Fabrikant D, Seyfullah LJ. Parallel evolution of angiosperm-like venation in Peltaspermales: a reinvestigation of Furcula. THE NEW PHYTOLOGIST 2024; 242:2845-2856. [PMID: 38623034 DOI: 10.1111/nph.19726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 03/15/2024] [Indexed: 04/17/2024]
Abstract
Leaf venation is a pivotal trait in the success of vascular plants. Whereas gymnosperms have single or sparsely branched parallel veins, angiosperms developed a hierarchical structure of veins that form a complex reticulum. Its physiological consequences are considered to have enabled angiosperms to dominate terrestrial ecosystems in the Late Cretaceous and Cenozoic. Although a hierarchical-reticulate venation also occurs in some groups of extinct seed plants, it is unclear whether these are stem relatives of angiosperms or have evolved these traits in parallel. Here, we re-examine the morphology of the enigmatic foliage taxon Furcula, a potential early Mesozoic angiosperm relative, and argue that its hierarchical vein network represents convergent evolution (in the Late Triassic) with flowering plants (which developed in the Early Cretaceous) based on details of vein architecture and the absence of angiosperm-like stomata and guard cells. We suggest that its nearest relatives are Peltaspermales similar to Scytophyllum and Vittaephyllum, the latter being a genus that originated during the Late Triassic (Carnian) and shares a hierarchical vein system with Furcula. We further suggest that the evolution of hierarchical venation systems in the early Permian, the Late Triassic, and the Early Cretaceous represent 'natural experiments' that might help resolve the selective pressures enabling this trait to evolve.
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Affiliation(s)
- Mario Coiro
- Department of Palaeontology, University of Vienna, 1090, Vienna, Austria
- Ronin Institute for Independent Scholarship, Montclair, NJ, 07043, USA
| | - Stephen McLoughlin
- Department of Palaeobiology, Swedish Museum of Natural History, 114 18, Stockholm, Sweden
| | - Margret Steinthorsdottir
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, 114 18, Stockholm, Sweden
- Bolin Centre for Climate Research, Stockholm University, 114 19, Stockholm, Sweden
| | - Vivi Vajda
- Department of Palaeobiology, Swedish Museum of Natural History, 114 18, Stockholm, Sweden
| | - Dolev Fabrikant
- The Hebrew University of Jerusalem, Jerusalem, 9190501, Israel
| | - Leyla J Seyfullah
- Department of Palaeontology, University of Vienna, 1090, Vienna, Austria
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2
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Bos R, Zheng W, Lindström S, Sanei H, Waajen I, Fendley IM, Mather TA, Wang Y, Rohovec J, Navrátil T, Sluijs A, van de Schootbrugge B. Climate-forced Hg-remobilization associated with fern mutagenesis in the aftermath of the end-Triassic extinction. Nat Commun 2024; 15:3596. [PMID: 38678037 DOI: 10.1038/s41467-024-47922-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 04/12/2024] [Indexed: 04/29/2024] Open
Abstract
The long-term effects of the Central Atlantic Magmatic Province, a large igneous province connected to the end-Triassic mass-extinction (201.5 Ma), remain largely elusive. Here, we document the persistence of volcanic-induced mercury (Hg) pollution and its effects on the biosphere for ~1.3 million years after the extinction event. In sediments recovered in Germany (Schandelah-1 core), we record not only high abundances of malformed fern spores at the Triassic-Jurassic boundary, but also during the lower Jurassic Hettangian, indicating repeated vegetation disturbance and stress that was eccentricity-forced. Crucially, these abundances correspond to increases in sedimentary Hg-concentrations. Hg-isotope ratios (δ202Hg, Δ199Hg) suggest a volcanic source of Hg-enrichment at the Triassic-Jurassic boundary but a terrestrial source for the early Jurassic peaks. We conclude that volcanically injected Hg across the extinction was repeatedly remobilized from coastal wetlands and hinterland areas during eccentricity-forced phases of severe hydrological upheaval and erosion, focusing Hg-pollution in the Central European Basin.
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Affiliation(s)
- Remco Bos
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Princetonlaan 8, 3584, CB, Utrecht, The Netherlands.
| | - Wang Zheng
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, 300072, Tianjin, China.
| | - Sofie Lindström
- Department of Geosciences and Natural Resource Management, Copenhagen University, Øster Voldgade 10, DK-1350, Copenhagen K, Denmark
| | - Hamed Sanei
- Lithospheric Organic Carbon (LOC) Group, Department of Geoscience, Aarhus University, Høegh-Guldbergs gade 2, 8000C, Aarhus, Denmark
| | - Irene Waajen
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Princetonlaan 8, 3584, CB, Utrecht, The Netherlands
| | - Isabel M Fendley
- Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, UK
- Department of Geosciences, Pennsylvania State University, University Park, PA, 16802, USA
| | - Tamsin A Mather
- Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, UK
| | - Yang Wang
- Institute of Surface-Earth System Science, School of Earth System Science, Tianjin University, 300072, Tianjin, China
| | - Jan Rohovec
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, Prague, 6 165 00, Czech Republic
| | - Tomáš Navrátil
- Institute of Geology of the Czech Academy of Sciences, Rozvojová 269, Prague, 6 165 00, Czech Republic
| | - Appy Sluijs
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Princetonlaan 8, 3584, CB, Utrecht, The Netherlands
| | - Bas van de Schootbrugge
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Princetonlaan 8, 3584, CB, Utrecht, The Netherlands
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3
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Algeo TJ, Shen J. Theory and classification of mass extinction causation. Natl Sci Rev 2024; 11:nwad237. [PMID: 38116094 PMCID: PMC10727847 DOI: 10.1093/nsr/nwad237] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/01/2023] [Accepted: 09/04/2023] [Indexed: 12/21/2023] Open
Abstract
Theory regarding the causation of mass extinctions is in need of systematization, which is the focus of this contribution. Every mass extinction has both an ultimate cause, i.e. the trigger that leads to various climato-environmental changes, and one or more proximate cause(s), i.e. the specific climato-environmental changes that result in elevated biotic mortality. With regard to ultimate causes, strong cases can be made that bolide (i.e. meteor) impacts, large igneous province (LIP) eruptions and bioevolutionary events have each triggered one or more of the Phanerozoic Big Five mass extinctions, and that tectono-oceanic changes have triggered some second-order extinction events. Apart from bolide impacts, other astronomical triggers (e.g. solar flares, gamma bursts and supernova explosions) remain entirely in the realm of speculation. With regard to proximate mechanisms, most extinctions are related to either carbon-release or carbon-burial processes, the former being associated with climatic warming, ocean acidification, reduced marine productivity and lower carbonate δ13C values, and the latter with climatic cooling, increased marine productivity and higher carbonate δ13C values. Environmental parameters such as marine redox conditions and terrestrial weathering intensity do not show consistent relationships with carbon-cycle changes. In this context, mass extinction causation can be usefully classified using a matrix of ultimate and proximate factors. Among the Big Five mass extinctions, the end-Cretaceous biocrisis is an example of a bolide-triggered carbon-release event, the end-Permian and end-Triassic biocrises are examples of LIP-triggered carbon-release events, and the Late Ordovician and Late Devonian biocrises are examples of bioevolution-triggered carbon-burial events. Whereas the bolide-impact and LIP-eruption mechanisms appear to invariably cause carbon release, bioevolutionary triggers can result in variable carbon-cycle changes, e.g. carbon burial during the Late Ordovician and Late Devonian events, carbon release associated with modern anthropogenic climate warming, and little to no carbon-cycle impact due to certain types of ecosystem change (e.g. the advent of the first predators around the end-Ediacaran; the appearance of Paleolithic human hunters in Australasia and the Americas). Broadly speaking, studies of mass extinction causation have suffered from insufficiently critical thinking-an impartial survey of the extant evidence shows that (i) hypotheses of a common ultimate cause (e.g. bolide impacts or LIP eruptions) for all Big Five mass extinctions are suspect given manifest differences in patterns of environmental and biotic change among them; (ii) the Late Ordovician and Late Devonian events were associated with carbon burial and long-term climatic cooling, i.e. changes that are inconsistent with a bolide-impact or LIP-eruption mechanism; and (iii) claims of periodicity in Phanerozoic mass extinctions depended critically on the now-disproven idea that they shared a common extrinsic trigger (i.e. bolide impacts).
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Affiliation(s)
- Thomas J Algeo
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences—Wuhan, Wuhan430074, China
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences—Wuhan, Wuhan430074, China
- Department of Geosciences, University of Cincinnati, Cincinnati, OH45221, USA
| | - Jun Shen
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences—Wuhan, Wuhan430074, China
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4
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Peng J, Slater SM, McLoughlin S, Vajda V. New species of Kuqaia from the Lower Jurassic of Sweden indicates a possible water flea (Crustacea: Branchiopoda) affinity. PLoS One 2023; 18:e0282247. [PMID: 37285340 DOI: 10.1371/journal.pone.0282247] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 02/07/2023] [Indexed: 06/09/2023] Open
Abstract
The enigmatic acid-resistant mesofossil genus Kuqaia is emended, a new species (Kuqaia scanicus) is instituted, and three established species are described from the Lower Jurassic (lower Pliensbachian) of the Kävlinge BH-928 core, in southern Sweden. Kuqaia has a distribution across the middle northern latitudes of Pangaea and is restricted to Lower to lower Middle Jurassic strata. Morphological characters support Kuqaia being the ephippia (resting egg/embryo cases) of Cladocera (Crustacea: Branchiopoda), and a probable early stem-group taxon of the Daphnia lineage. The paleoecology of the small planktonic crustaceans indicate purely fresh-water environments, such as lakes or ponds, all occurrences being in continental deposits, and the Kuqaia specimens possibly represent dry-season resting eggs. Chemical analyses of these and similar fossils, and of extant invertebrate eggs and egg cases are recommended to improve resolution of the biological affiliations of such mesofossil groups.
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Affiliation(s)
- Jungang Peng
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, China
- Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden
| | - Sam M Slater
- Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden
| | - Stephen McLoughlin
- Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden
| | - Vivi Vajda
- Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden
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5
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Singh P, Lu W, Lu Z, Jost AB, Lau K, Bachan A, van de Schootbrugge B, Payne JL. Reduction in animal abundance and oxygen availability during and after the end-Triassic mass extinction. GEOBIOLOGY 2023; 21:175-192. [PMID: 36329603 DOI: 10.1111/gbi.12533] [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: 01/11/2022] [Revised: 09/27/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
The end-Triassic biodiversity crisis was one of the most severe mass extinctions in the history of animal life. However, the extent to which the loss of taxonomic diversity was coupled with a reduction in organismal abundance remains to be quantified. Further, the temporal relationship between organismal abundance and local marine redox conditions is lacking in carbonate sections. To address these questions, we measured skeletal grain abundance in shallow-marine limestones by point counting 293 thin sections from four stratigraphic sections across the Triassic/Jurassic boundary in the Lombardy Basin and Apennine Platform of western Tethys. Skeletal abundance decreased abruptly across the Triassic/Jurassic boundary in all stratigraphic sections. The abundance of skeletal organisms remained low throughout the lower-middle Hettangian strata and began to rebound during the late Hettangian and early Sinemurian. A two-way ANOVA indicates that sample age (p < .01, η2 = 0.30) explains more of the variation in skeletal abundance than the depositional environment or paleobathymetry (p < .01, η2 = 0.15). Measured I/Ca ratios, a proxy for local shallow-marine redox conditions, show this same pattern with the lowest I/Ca ratios occurring in the early Hettangian. The close correspondence between oceanic water column oxygen levels and skeletal abundance indicates a connection between redox conditions and benthic organismal abundance across the Triassic/Jurassic boundary. These findings indicate that the end-Triassic mass extinction reduced not only the biodiversity but also the carrying capacity for skeletal organisms in early Hettangian ecosystems, adding to evidence that mass extinction of species generally leads to mass rarity among survivors.
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Affiliation(s)
- Pulkit Singh
- Department of Geological Sciences, Stanford University, Stanford, California, USA
| | - Wanyi Lu
- Department of Earth and Environmental Sciences, Syracuse University, Syracuse, New York, USA
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Zunli Lu
- Department of Earth and Environmental Sciences, Syracuse University, Syracuse, New York, USA
| | - Adam B Jost
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kimberly Lau
- Department of Geosciences and Earth and Environmental Systems Institute, Penn State University, University Park, Pennsylvania, USA
| | | | | | - Jonathan L Payne
- Department of Geological Sciences, Stanford University, Stanford, California, USA
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6
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Baker SJ, Dewhirst RA, McElwain JC, Haworth M, Belcher CM. CO 2 -induced biochemical changes in leaf volatiles decreased fire-intensity in the run-up to the Triassic-Jurassic boundary. THE NEW PHYTOLOGIST 2022; 235:1442-1454. [PMID: 35672945 PMCID: PMC9545750 DOI: 10.1111/nph.18299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
The Triassic-Jurassic boundary marks the third largest mass extinction event in the Phanerozoic, characterized by a rise in CO2 -concentrations from c. 600 ppm to c. 2100-2400 ppm, coupled with a c. 3.0-4.0°C temperature rise. This is hypothesized to have induced major floral turnover, altering vegetation structure, composition and leaf morphology, which in turn are hypothesized to have driven changes in wildfire. However, the effects of elevated CO2 on fuel properties, such as chemical composition of leaves, are also important in influencing fire behaviour, but yet have not been considered. We test this by selecting three Triassic analogue species grown experimentally in different atmospheric compositions, and analyse variations in leaf chemistry, and leaf level flammability. These data were used to inform a fire behaviour model. We find that all three species tested showed a reduction in their volatile component, leading to lower flammability. Accounting for these variations in a model, our results suggest that leaf intrinsic flammability has a measurable impact on modelled fire behaviour. If scaled up to ecosystem level, periods of elevated CO2 may therefore be capable of inducing both biochemical and morphological changes in fuel properties, and thus may be capable of influencing fire behaviour.
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Affiliation(s)
| | | | - Jennifer C. McElwain
- Botany Department, School of Natural SciencesTrinity College DublinDublinD02 PN40Ireland
| | - Matthew Haworth
- Institute for Sustainable Plant ProtectionNational Research Council (CNR‐IPSP)Via Madonna del Piano 10 Sesto FiorentinoFlorenceFirenze50019Italy
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7
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Olsen P, Sha J, Fang Y, Chang C, Whiteside JH, Kinney S, Sues HD, Kent D, Schaller M, Vajda V. Arctic ice and the ecological rise of the dinosaurs. SCIENCE ADVANCES 2022; 8:eabo6342. [PMID: 35776799 PMCID: PMC10883366 DOI: 10.1126/sciadv.abo6342] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Abundant lake ice-rafted debris in Late Triassic and earliest Jurassic strata of the Junggar Basin of northwestern China (paleolatitude ~71°N) indicates that freezing winter temperatures typified the forested Arctic, despite a persistence of extremely high levels of atmospheric Pco2 (partial pressure of CO2). Phylogenetic bracket analysis shows that non-avian dinosaurs were primitively insulated, enabling them to access rich deciduous and evergreen Arctic vegetation, even under freezing winter conditions. Transient but intense volcanic winters associated with massive eruptions and lowered light levels led to the end-Triassic mass extinction (201.6 Ma) on land, decimating all medium- to large-sized nondinosaurian, noninsulated continental reptiles. In contrast, insulated dinosaurs were already well adapted to cold temperatures, and not only survived but also underwent a rapid adaptive radiation and ecological expansion in the Jurassic, taking over regions formerly dominated by large noninsulated reptiles.
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Affiliation(s)
- Paul Olsen
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10968, USA
| | - Jingeng Sha
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yanan Fang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Clara Chang
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10968, USA
| | - Jessica H Whiteside
- School of Ocean and Earth Sciences, National Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
| | - Sean Kinney
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10968, USA
| | - Hans-Dieter Sues
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA
| | - Dennis Kent
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10968, USA
- Earth and Planetary Sciences, Rutgers University, Piscataway, NJ 08854, USA
| | - Morgan Schaller
- Earth and Environmental Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Vivi Vajda
- Department of Palaeobiology, Swedish Museum of Natural History, Stockholm, Sweden
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8
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Zhang P, Lu J, Yang M, Bond DPG, Greene SE, Liu L, Zhang Y, Wang Y, Wang Z, Li S, Shao L, Hilton J. Volcanically-Induced Environmental and Floral Changes Across the Triassic-Jurassic (T-J) Transition. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.853404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The End-Triassic Mass Extinction (ETME) saw the catastrophic loss of ca. 50% of marine genera temporally associated with emplacement of the Central Atlantic Magmatic Province (CAMP). However, the effects of the ETME on land is a controversial topic. Evaluation of the disparate cause(s) and effects of the extinction requires additional, detailed terrestrial records of these events. Here, we present a multidisciplinary record of volcanism and environmental change from an expanded Triassic-Jurassic (T-J) transition preserved in lacustrine sediments from the Jiyuan Basin, North China. High-resolution chemostratigraphy, palynological, kerogen, and sedimentological data reveal that terrestrial conditions responded to and were defined by large-scale volcanism. The record of sedimentary mercury reveals two discrete CAMP eruptive phases during the T-J transition. Each of these can be correlated with large, negative C isotope excursions (CIE-I of −4.7‰; CIE-II of −2.9‰), significantly reduced plant diversity (with ca. 45 and 44% generic losses, respectively), enhanced wildfire (marked by increased fusinite or charcoal content), and major climatic shifts toward drier and hotter conditions (indicated by the occurrence of calcareous nodules, increased Classopollis pollen content, and PCA analysis). Our results show that CAMP eruptions may have followed a bimodal eruptive model and demonstrate the powerful ability of large-scale volcanism to alter the global C cycle and profoundly affect the climate, in turn leading to enhanced wildfires and a collapse in land plant diversity during the T-J transition.
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9
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Shen J, Yin R, Algeo TJ, Svensen HH, Schoepfer SD. Mercury evidence for combustion of organic-rich sediments during the end-Triassic crisis. Nat Commun 2022; 13:1307. [PMID: 35264554 PMCID: PMC8907283 DOI: 10.1038/s41467-022-28891-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 02/15/2022] [Indexed: 11/09/2022] Open
Abstract
The sources of isotopically light carbon released during the end-Triassic mass extinction remain in debate. Here, we use mercury (Hg) concentrations and isotopes from a pelagic Triassic–Jurassic boundary section (Katsuyama, Japan) to track changes in Hg cycling. Because of its location in the central Panthalassa, far from terrigenous runoff, Hg enrichments at Katsuyama record atmospheric Hg deposition. These enrichments are characterized by negative mass independent fractionation (MIF) of odd Hg isotopes, providing evidence of their derivation from terrestrial organic-rich sediments (Δ199Hg < 0‰) rather than from deep-Earth volcanic gases (Δ199Hg ~ 0‰). Our data thus provide evidence that combustion of sedimentary organic matter by igneous intrusions and/or wildfires played a significant role in the environmental perturbations accompanying the event. This process has a modern analog in anthropogenic combustion of fossil fuels from crustal reservoirs. Mercury (Hg) concentrations and isotopes from a deep-ocean Triassic–Jurassic (~201 Ma) boundary section provide evidence of large inputs from terrestrial organic-rich sources through combustion by magmatic sills and wildfires.
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Affiliation(s)
- Jun Shen
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei, 430074, P.R. China.
| | - Runsheng Yin
- State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, Guizhou, 550081, P.R. China.
| | - Thomas J Algeo
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, Hubei, 430074, P.R. China.,State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, Hubei, 430074, P.R. China.,Department of Geology, University of Cincinnati, Cincinnati, OH, 45221-0013, USA
| | - Henrik H Svensen
- Centre for Earth Evolution and Dynamics (CEED), University of Oslo, Oslo, Norway
| | - Shane D Schoepfer
- Department of Geoscience and Natural Resources, Western Carolina University, Cullowhee, NC, 28723, USA
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10
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Intensified continental chemical weathering and carbon-cycle perturbations linked to volcanism during the Triassic-Jurassic transition. Nat Commun 2022; 13:299. [PMID: 35027546 PMCID: PMC8758789 DOI: 10.1038/s41467-022-27965-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 01/03/2022] [Indexed: 11/08/2022] Open
Abstract
Direct evidence of intense chemical weathering induced by volcanism is rare in sedimentary successions. Here, we undertake a multiproxy analysis (including organic carbon isotopes, mercury (Hg) concentrations and isotopes, chemical index of alteration (CIA), and clay minerals) of two well-dated Triassic-Jurassic (T-J) boundary sections representing high- and low/middle-paleolatitude sites. Both sections show increasing CIA in association with Hg peaks near the T-J boundary. We interpret these results as reflecting volcanism-induced intensification of continental chemical weathering, which is also supported by negative mass-independent fractionation (MIF) of odd Hg isotopes. The interval of enhanced chemical weathering persisted for ~2 million years, which is consistent with carbon-cycle model results of the time needed to drawdown excess atmospheric CO2 following a carbon release event. Lastly, these data also demonstrate that high-latitude continental settings are more sensitive than low/middle-latitude sites to shifts in weathering intensity during climatic warming events.
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11
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Song H, Kemp DB, Tian L, Chu D, Song H, Dai X. Thresholds of temperature change for mass extinctions. Nat Commun 2021; 12:4694. [PMID: 34349121 PMCID: PMC8338942 DOI: 10.1038/s41467-021-25019-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 07/16/2021] [Indexed: 11/26/2022] Open
Abstract
Climate change is a critical factor affecting biodiversity. However, the quantitative relationship between temperature change and extinction is unclear. Here, we analyze magnitudes and rates of temperature change and extinction rates of marine fossils through the past 450 million years (Myr). The results show that both the rate and magnitude of temperature change are significantly positively correlated with the extinction rate of marine animals. Major mass extinctions in the Phanerozoic can be linked to thresholds in climate change (warming or cooling) that equate to magnitudes >5.2 °C and rates >10 °C/Myr. The significant relationship between temperature change and extinction still exists when we exclude the five largest mass extinctions of the Phanerozoic. Our findings predict that a temperature increase of 5.2 °C above the pre-industrial level at present rates of increase would likely result in mass extinction comparable to that of the major Phanerozoic events, even without other, non-climatic anthropogenic impacts.
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Affiliation(s)
- Haijun Song
- State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China.
| | - David B Kemp
- State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Li Tian
- State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Daoliang Chu
- State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Huyue Song
- State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Xu Dai
- State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China
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12
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Singh SA, Elsler A, Stubbs TL, Bond R, Rayfield EJ, Benton MJ. Niche partitioning shaped herbivore macroevolution through the early Mesozoic. Nat Commun 2021; 12:2796. [PMID: 33990610 PMCID: PMC8121902 DOI: 10.1038/s41467-021-23169-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 04/16/2021] [Indexed: 02/04/2023] Open
Abstract
The Triassic (252-201 Ma) marks a major punctuation in Earth history, when ecosystems rebuilt themselves following the devastating Permian-Triassic mass extinction. Herbivory evolved independently several times as ecosystems comprising diverse assemblages of therapsids, parareptiles and archosauromorphs rose and fell, leading to a world dominated by dinosaurs. It was assumed that dinosaurs prevailed either through long-term competitive replacement of the incumbent clades or rapidly and opportunistically following one or more extinction events. Here we use functional morphology and ecology to explore herbivore morphospace through the Triassic and Early Jurassic. We identify five main herbivore guilds (ingestion generalists, prehension specialists, durophagous specialists, shearing pulpers, and heavy oral processors), and find that herbivore clades generally avoided competition by almost exclusively occupying different guilds. Major ecosystem remodelling was triggered multiple times by external environmental challenges, and previously dominant herbivores were marginalised by newly emerging forms. Dinosaur dominance was a mix of opportunity following disaster, combined with competitive advantage in their new world.
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Affiliation(s)
- Suresh A Singh
- School of Earth Sciences, University of Bristol, Bristol, UK.
| | - Armin Elsler
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - Thomas L Stubbs
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - Russell Bond
- School of Earth Sciences, University of Bristol, Bristol, UK
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13
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Northward dispersal of dinosaurs from Gondwana to Greenland at the mid-Norian (215-212 Ma, Late Triassic) dip in atmospheric pCO 2. Proc Natl Acad Sci U S A 2021; 118:2020778118. [PMID: 33593914 DOI: 10.1073/pnas.2020778118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The earliest dinosaurs (theropods and sauropodomorphs) are found in fossiliferous early Late Triassic strata dated to about 230 million years ago (Ma), mainly in northwestern Argentina and southern Brazil in the Southern Hemisphere temperate belt of what was Gondwana in Pangea. Sauropodomorphs, which are not known for the entire Triassic in then tropical North America, eventually appear 15 million years later in the Northern Hemisphere temperate belt of Laurasia. The Pangea supercontinent was traversable in principle by terrestrial vertebrates, so the main barrier to be surmounted for dispersal between hemispheres was likely to be climatic; in particular, the intense aridity of tropical desert belts and unstable climate in the equatorial humid belt accompanying high atmospheric pCO2 that characterized the Late Triassic. We revisited the chronostratigraphy of the dinosaur-bearing Fleming Fjord Group of central East Greenland and, with additional data, produced a correlation of a detailed magnetostratigraphy from more than 325 m of composite section from two field areas to the age-calibrated astrochronostratigraphic polarity time scale. This age model places the earliest occurrence of sauropodomorphs (Plateosaurus) in their northernmost range to ∼214 Ma. The timing is within the 215 to 212 Ma (mid-Norian) window of a major, robust dip in atmospheric pCO2 of uncertain origin but which may have resulted in sufficiently lowered climate barriers that facilitated the initial major dispersal of the herbivorous sauropodomorphs to the temperate belt of the Northern Hemisphere. Indications are that carnivorous theropods may have had dispersals that were less subject to the same climate constraints.
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14
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Wang CL, Liu LH, Wang JY, Yu XC, Yan K. Micron-Nanometer Evaporite Mineral Compositions in the Jiangling Depression, Jianghan Basin, China, by Means of Scanning Electron Microscopy. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2021; 21:310-325. [PMID: 33213632 DOI: 10.1166/jnn.2021.18564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Scanning electron microscopy (SEM) was used to analyze and study micron-nanometer evaporite samples collected from Paleocene and Eocene drill cores in the Jiangling Depression. Accordingly, seven beds of potassium-bearing solid rocks were accurately identified. Sylvite, carnallite, syngenite, dolomite, thenardite, anhydrite, glauberite, halite, barite, celestite, and other solid salt minerals were found, and carnallite, syngenite, and thenardite were found for the first time in the Jiangling Depression. Sylvite, syngenite, and carnallite indicate that the Paleogene salt lakes in the Jiangling Depression had evolved to the sylvite stage and that prospecting for solid sylvite would be satisfactory. Micron-nanometer celestite is contained in the evaporites, from which we can infer that strontium may have been provided by deep formation water (or oil-field water). This finding is of great significance to studying the genesis of sylvite sediment in the Jiangling Depression. From the extensive development of primary glauberite beds typical of warm salt minerals in the Shashi Formation, it can be inferred that the late Paleogene paleoclimate in the Jiangling Depression of the Jianghan Basin was dry and hot. Based on the extensive distribution of micron-nanometer pyrite, siderite, iron and Fe₂O₃/FeO ratios in evaporite sediments and color analysis of mudstones, the evaporites in the study area formed in an underwater anoxic, reducing environment during sedimentation. Therefore, the evaporite sediments in the Paleocene-Eocene interval of the Jiangling Depression are proposed to have formed in a saltwater lake sedimentary environment, and the ancient lake was characterized by a deep-water salt lake sedimentary model.
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Affiliation(s)
- Chun-Lian Wang
- MNR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
| | - Li-Hong Liu
- Oil & Gas Survey, China Geological Survey, Beijing 100083, China
| | - Jiu-Yi Wang
- MNR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
| | - Xiao-Can Yu
- State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
| | - Kai Yan
- MNR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
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15
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Kanayama Y, Iwasa Y. Why did sauropod dinosaurs grow so big? - A possible answer from the life history theory. J Theor Biol 2020; 508:110485. [PMID: 32918924 DOI: 10.1016/j.jtbi.2020.110485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/30/2020] [Accepted: 09/03/2020] [Indexed: 11/19/2022]
Abstract
Dinosaurs are known for their large body size. Sauropod dinosaurs (Sauropodomorpha) had an especially large body size; some species reached 30 m long and 50 tons. Many hypotheses have been proposed to explain this phenomenon. In this study we examined this question using the life history theory. We constructed a simple model of life history with the following assumptions: the body size of immature individuals increases following a logistic equation. A higher quality and availability of food plants make the initial growth rate faster and the final saturating size larger. The increase in body size stops once reproduction starts. Fertility increases with adult body size and food-plant quality. Mortality due to predation is mitigated by a larger body size. We calculated the optimal body size at maturity that would maximize the lifetime reproductive success or fitness. The analysis showed that adult body size increased with food-plant quality and availability but decreased with higher mortality due to predators and other factors. This conclusion is consistent with geological studies that suggest a high quality and availability of food plants in the Mesozoic era, efficient air-sac breathing, and the lightweight bones of sauropod dinosaurs, allowing rapid growth of small individuals.
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Affiliation(s)
- Yuki Kanayama
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda-shi, Hyogo 669-1337, Japan
| | - Yoh Iwasa
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda-shi, Hyogo 669-1337, Japan
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16
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Meeus S, Van den Bulcke J, wyffels F. From leaf to label: A robust automated workflow for stomata detection. Ecol Evol 2020; 10:9178-9191. [PMID: 32953053 PMCID: PMC7487252 DOI: 10.1002/ece3.6571] [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: 03/18/2020] [Revised: 06/11/2020] [Accepted: 06/15/2020] [Indexed: 12/24/2022] Open
Abstract
Plant leaf stomata are the gatekeepers of the atmosphere-plant interface and are essential building blocks of land surface models as they control transpiration and photosynthesis. Although more stomatal trait data are needed to significantly reduce the error in these model predictions, recording these traits is time-consuming, and no standardized protocol is currently available. Some attempts were made to automate stomatal detection from photomicrographs; however, these approaches have the disadvantage of using classic image processing or targeting a narrow taxonomic entity which makes these technologies less robust and generalizable to other plant species. We propose an easy-to-use and adaptable workflow from leaf to label. A methodology for automatic stomata detection was developed using deep neural networks according to the state of the art and its applicability demonstrated across the phylogeny of the angiosperms.We used a patch-based approach for training/tuning three different deep learning architectures. For training, we used 431 micrographs taken from leaf prints made according to the nail polish method from herbarium specimens of 19 species. The best-performing architecture was tested on 595 images of 16 additional species spread across the angiosperm phylogeny.The nail polish method was successfully applied in 78% of the species sampled here. The VGG19 architecture slightly outperformed the basic shallow and deep architectures, with a confidence threshold equal to 0.7 resulting in an optimal trade-off between precision and recall. Applying this threshold, the VGG19 architecture obtained an average F-score of 0.87, 0.89, and 0.67 on the training, validation, and unseen test set, respectively. The average accuracy was very high (94%) for computed stomatal counts on unseen images of species used for training.The leaf-to-label pipeline is an easy-to-use workflow for researchers of different areas of expertise interested in detecting stomata more efficiently. The described methodology was based on multiple species and well-established methods so that it can serve as a reference for future work.
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Affiliation(s)
| | | | - Francis wyffels
- Department of Electronics and Information SystemsIDLab‐AIROGhent University‐‐imecZwijnaardeBelgium
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17
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Xu SY, Weng J. Climate change shapes the future evolution of plant metabolism. ADVANCED GENETICS (HOBOKEN, N.J.) 2020; 1:e10022. [PMID: 36619247 PMCID: PMC9744464 DOI: 10.1002/ggn2.10022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/13/2020] [Accepted: 03/02/2020] [Indexed: 01/11/2023]
Abstract
Planet Earth has experienced many dramatic atmospheric and climatic changes throughout its 4.5-billion-year history that have profoundly impacted the evolution of life as we know it. Photosynthetic organisms, and specifically plants, have played a paramount role in shaping the Earth's atmosphere through oxygen production and carbon sequestration. In turn, the diversity of plants has been shaped by historical atmospheric and climatic changes: plants rose to this challenge by evolving new developmental and metabolic traits. These adaptive traits help plants to thrive in diverse growth conditions, while benefiting humanity through the production of food, raw materials, and medicines. However, the current rapid rate of climate change caused by human activities presents unprecedented new challenges to the future of plants. Here, we discuss the potential effects of modern climate change on plants, with specific attention to plant specialized metabolism. We explore potential avenues of future scientific investigations, powered by cutting-edge methods such as synthetic biology and genome engineering, to better understand and mitigate the consequences of rapid climate change on plant fitness and plant usage by humans.
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Affiliation(s)
- Sophia Y. Xu
- Whitehead Institute for Biomedical ResearchCambridgeMassachusettsUSA,Department of BiologyMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
| | - Jing‐Ke Weng
- Whitehead Institute for Biomedical ResearchCambridgeMassachusettsUSA,Department of BiologyMassachusetts Institute of TechnologyCambridgeMassachusettsUSA
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18
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Payne JL, Bachan A, Heim NA, Hull PM, Knope ML. The evolution of complex life and the stabilization of the Earth system. Interface Focus 2020; 10:20190106. [PMID: 32642051 PMCID: PMC7333899 DOI: 10.1098/rsfs.2019.0106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2020] [Indexed: 11/12/2022] Open
Abstract
The half-billion-year history of animal evolution is characterized by decreasing rates of background extinction. Earth's increasing habitability for animals could result from several processes: (i) a decrease in the intensity of interactions among species that lead to extinctions; (ii) a decrease in the prevalence or intensity of geological triggers such as flood basalt eruptions and bolide impacts; (iii) a decrease in the sensitivity of animals to environmental disturbance; or (iv) an increase in the strength of stabilizing feedbacks within the climate system and biogeochemical cycles. There is no evidence that the prevalence or intensity of interactions among species or geological extinction triggers have decreased over time. There is, however, evidence from palaeontology, geochemistry and comparative physiology that animals have become more resilient to an environmental change and that the evolution of complex life has, on the whole, strengthened stabilizing feedbacks in the climate system. The differential success of certain phyla and classes appears to result, at least in part, from the anatomical solutions to the evolution of macroscopic size that were arrived at largely during Ediacaran and Cambrian time. Larger-bodied animals, enabled by increased anatomical complexity, were increasingly able to mix the marine sediment and water columns, thus promoting stability in biogeochemical cycles. In addition, body plans that also facilitated ecological differentiation have tended to be associated with lower rates of extinction. In this sense, Cambrian solutions to Cambrian problems have had a lasting impact on the trajectory of complex life and, in turn, fundamental properties of the Earth system.
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Affiliation(s)
- Jonathan L. Payne
- Department of Geological Sciences, Stanford University, 450 Serra Mall, Building 320, Stanford, CA 94305, USA
| | - Aviv Bachan
- Department of Geological Sciences, Stanford University, 450 Serra Mall, Building 320, Stanford, CA 94305, USA
| | - Noel A. Heim
- Department of Earth and Ocean Sciences, Tufts University, Medford, MA 02155, USA
| | - Pincelli M. Hull
- Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA
| | - Matthew L. Knope
- Department of Biology, University of Hawaii-Hilo, 200 West Kawili Street, Hilo, HI 96720, USA
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19
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Khlebodarova TM, Likhoshvai VA. Causes of global extinctions in the history of life: facts and hypotheses. Vavilovskii Zhurnal Genet Selektsii 2020; 24:407-419. [PMID: 33659824 PMCID: PMC7716527 DOI: 10.18699/vj20.633] [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: 11/19/2022] Open
Abstract
Paleontologists define global extinctions on Earth as a loss of about three-quarters of plant and animal species over a relatively short period of time. At least five global extinctions are documented in the Phanerozoic fossil record (~500-million-year period): ~65, 200, 260, 380, and 440 million years ago. In addition, there is evidence of global extinctions in earlier periods of life on Earth - during the Late Cambrian (~500 million years ago) and Ediacaran periods (more than 540 million years ago). There is still no common opinion on the causes of their occurrence. The current study is a systematized review of the data on recorded extinctions of complex life forms on Earth from the moment of their occurrence during the Ediacaran period to the modern period. The review discusses possible causes for mass extinctions in the light of the influence of abiogenic factors, planetary or astronomical, and the consequences of their actions. We evaluate the pros and cons of the hypothesis on the presence of periodicity in the extinction of Phanerozoic marine biota. Strong evidence that allows us to hypothesize that additional mechanisms associated with various internal biotic factors are responsible for the emergence of extinctions in the evolution of complex life forms is discussed. Developing the idea of the internal causes of periodicity and discontinuity in evolution, we propose our own original hypothesis, according to which the bistability phenomenon underlies the complex dynamics of the biota development, which is manifested in the form of global extinctions. The bistability phenomenon arises only in ecosystems with predominant sexual reproduction. Our hypothesis suggests that even in the absence of global abiotic catastrophes, extinctions of biota would occur anyway. However, our hypothesis does not exclude the possibility that in different periods of the Earth's history the biota was subjected to powerful external influences that had a significant impact on its further development, which is reflected in the Earth's fossil record.
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Affiliation(s)
- T M Khlebodarova
- Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - V A Likhoshvai
- Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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20
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Thermogenic carbon release from the Central Atlantic magmatic province caused major end-Triassic carbon cycle perturbations. Proc Natl Acad Sci U S A 2020; 117:11968-11974. [PMID: 32424084 DOI: 10.1073/pnas.2000095117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Central Atlantic magmatic province (CAMP), the end-Triassic mass extinction (ETE), and associated major carbon cycle perturbations occurred synchronously around the Triassic-Jurassic (T-J) boundary (201 Ma). Negative carbon isotope excursions (CIEs) recorded in marine and terrestrial sediments attest to the input of isotopically light carbon, although the carbon sources remain debated. Here, we explore the effects of mantle-derived and thermogenic carbon released from the emplacement of CAMP using the long-term ocean-atmosphere-sediment carbon cycle reservoir (LOSCAR) model. We have tested a detailed emission scenario grounded by numerous complementary boundary conditions, aiming to model the full extent of the carbon cycle perturbations around the T-J boundary. These include three negative CIEs (i.e., Marshi/Precursor, Spelae/Initial, Tilmanni/Main) with sharp positive CIEs in between. We show that a total of ∼24,000 Gt C (including ∼12,000 Gt thermogenic C) replicates the proxy data. These results indicate that thermogenic carbon generated from the contact aureoles around CAMP sills represents a credible source for the negative CIEs. An extremely isotopically depleted carbon source, such as marine methane clathrates, is therefore not required. Furthermore, we also find that significant organic carbon burial, in addition to silicate weathering, is necessary to account for the positive δ13C intervals following the negative CIEs.
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21
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Deep CO 2 in the end-Triassic Central Atlantic Magmatic Province. Nat Commun 2020; 11:1670. [PMID: 32265448 PMCID: PMC7138847 DOI: 10.1038/s41467-020-15325-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 03/02/2020] [Indexed: 11/09/2022] Open
Abstract
Large Igneous Province eruptions coincide with many major Phanerozoic mass extinctions, suggesting a cause-effect relationship where volcanic degassing triggers global climatic changes. In order to fully understand this relationship, it is necessary to constrain the quantity and type of degassed magmatic volatiles, and to determine the depth of their source and the timing of eruption. Here we present direct evidence of abundant CO2 in basaltic rocks from the end-Triassic Central Atlantic Magmatic Province (CAMP), through investigation of gas exsolution bubbles preserved by melt inclusions. Our results indicate abundance of CO2 and a mantle and/or lower-middle crustal origin for at least part of the degassed carbon. The presence of deep carbon is a key control on the emplacement mode of CAMP magmas, favouring rapid eruption pulses (a few centuries each). Our estimates suggest that the amount of CO2 that each CAMP magmatic pulse injected into the end-Triassic atmosphere is comparable to the amount of anthropogenic emissions projected for the 21st century. Such large volumes of volcanic CO2 likely contributed to end-Triassic global warming and ocean acidification.
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22
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Platinum-group elements link the end-Triassic mass extinction and the Central Atlantic Magmatic Province. Sci Rep 2020; 10:3482. [PMID: 32103087 PMCID: PMC7044291 DOI: 10.1038/s41598-020-60483-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 02/07/2020] [Indexed: 11/14/2022] Open
Abstract
Elevated concentrations of iridium (Ir) and other platinum-group elements (PGE) have been reported in both terrestrial and marine sediments associated with the end-Triassic mass extinction (ETE) c. 201.5 million years ago. The source of the PGEs has been attributed to condensed vapor and melt from an extraterrestrial impactor or to volcanism. Here we report new PGE data for volcanic rocks of the Central Atlantic Magmatic Province (CAMP) in Morocco and show that their Pd/Ir, Pt/Ir and Pt/Rh ratios are similar to marine and terrestrial sediments at the ETE, and very different from potential impactors. Hence, we propose the PGEs provide a new temporal correlation of CAMP volcanism to the ETE, corroborating the view that mass extinctions may be caused by volcanism.
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23
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Budd GE, Mann RP. The dynamics of stem and crown groups. SCIENCE ADVANCES 2020; 6:eaaz1626. [PMID: 32128421 PMCID: PMC7030935 DOI: 10.1126/sciadv.aaz1626] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 12/03/2019] [Indexed: 05/22/2023]
Abstract
The fossil record of the origins of major groups such as animals and birds has generated considerable controversy, especially when it conflicts with timings based on molecular clock estimates. Here, we model the diversity of "stem" (basal) and "crown" (modern) members of groups using a "birth-death model," the results of which qualitatively match many large-scale patterns seen in the fossil record. Typically, the stem group diversifies rapidly until the crown group emerges, at which point its diversity collapses, followed shortly by its extinction. Mass extinctions can disturb this pattern and create long stem groups such as the dinosaurs. Crown groups are unlikely to emerge either cryptically or just before mass extinctions, in contradiction to popular hypotheses such as the "phylogenetic fuse". The patterns revealed provide an essential context for framing ecological and evolutionary explanations for how major groups originate, and strengthen our confidence in the reliability of the fossil record.
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Affiliation(s)
- Graham E. Budd
- Department of Earth Sciences, Palaeobiology Programme, Uppsala University, Uppsala, Sweden
- Corresponding author.
| | - Richard P. Mann
- Department of Statistics, School of Mathematics, University of Leeds, Leeds, UK
- The Alan Turing Institute, London, UK
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24
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Bordy EM, Rampersadh A, Abrahams M, Lockley MG, Head HV. Tracking the Pliensbachian-Toarcian Karoo firewalkers: Trackways of quadruped and biped dinosaurs and mammaliaforms. PLoS One 2020; 15:e0226847. [PMID: 31995575 PMCID: PMC6988920 DOI: 10.1371/journal.pone.0226847] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/05/2019] [Indexed: 11/19/2022] Open
Abstract
The Karoo igneous rocks represent one of the largest continental flood basalt events (by volume) on Earth, and are not normally associated with fossils remains. However, these Pliensbachian–Toarcian lava flows contain sandstone interbeds that are particularly common in the lower part of the volcanic succession and are occasionally fossiliferous. On a sandstone interbed in the northern main Karoo Basin, we discovered twenty-five tridactyl and tetradactyl vertebrate tracks comprising five trackways. The tracks are preserved among desiccation cracks and low-amplitude, asymmetrical ripple marks, implying deposition in low energy, shallow, ephemeral water currents. Based on footprint lengths of 2–14 cm and trackway patterns, the trackmakers were both bipedal and quadrupedal animals of assorted sizes with walking and running gaits. We describe the larger tridactyl tracks as “grallatorid” and attribute them to bipedal theropod dinosaurs, like Coelophysis, a genus common in the Early Jurassic of southern Africa. The smallest tracks are tentatively interpreted as Brasilichnium-like tracks, which are linked to synapsid trackmakers, a common attribution of similar tracks from the Lower to Middle Jurassic record of southern and southwestern Gondwana. The trackway of an intermediate-sized quadruped reveals strong similarities in morphometric parameters to a post-Karoo Zimbabwean trackway from Chewore. These trackways are classified here as a new ichnogenus attributable to small ornithischian dinosaurs as yet without a body fossil record in southern Africa. These tracks not only suggest that dinosaurs and therapsids survived the onset of the Drakensberg volcanism, but also that theropods, ornithischians and synapsids were among the last vertebrates that inhabited the main Karoo Basin some 183 Ma ago. Although these vertebrates survived the first Karoo volcanic eruptions, their rapidly dwindling habitat was turned into a land of fire as it was covered by the outpouring lavas during one of the most dramatic geological episodes in southern Africa.
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Affiliation(s)
- Emese M. Bordy
- Department of Geological Sciences, University of Cape Town, Cape Town, South Africa
- * E-mail:
| | - Akhil Rampersadh
- Department of Geological Sciences, University of Cape Town, Cape Town, South Africa
| | - Miengah Abrahams
- Department of Geological Sciences, University of Cape Town, Cape Town, South Africa
| | - Martin G. Lockley
- Dinosaur Tracks Museum, University of Colorado Denver, Denver, Colorado, United States of America
| | - Howard V. Head
- Department of Geological Sciences, University of Cape Town, Cape Town, South Africa
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25
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Larina E, Bottjer DJ, Corsetti FA, Zonneveld JP, Celestian AJ, Bailey JV. Uppermost Triassic phosphorites from Williston Lake, Canada: link to fluctuating euxinic-anoxic conditions in northeastern Panthalassa before the end-Triassic mass extinction. Sci Rep 2019; 9:18790. [PMID: 31827166 PMCID: PMC6906467 DOI: 10.1038/s41598-019-55162-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/19/2019] [Indexed: 12/02/2022] Open
Abstract
The end-Triassic mass extinction (ETE) is associated with a rise in CO2 due to eruptions of the Central Atlantic Magmatic Province (CAMP), and had a particularly dramatic effect on the Modern Fauna, so an understanding of the conditions that led to the ETE has relevance to current rising CO2 levels. Here, we report multiple phosphorite deposits in strata that immediately precede the ETE at Williston Lake, Canada, which allow the paleoenvironmental conditions leading up to the mass extinction to be investigated. The predominance of phosphatic coated grains within phoshorites indicates reworking in shallow water environments. Raman spectroscopy reveals that the phosphorites contain organic carbon, and petrographic and scanning electron microscopic analyses reveal that the phosphorites contain putative microfossils, potentially suggesting microbial involvement in a direct or indirect way. Thus, we favor a mechanism of phosphogenesis that involves microbial polyphosphate metabolism in which phosphatic deposits typically form at the interface of euxinic/anoxic and oxic conditions. When combined with data from deeper water deposits (Kennecott Point) far to the southwest, it would appear a very broad area of northeastern Panthalassa experienced anoxic to euxinic bottom water conditions in the direct lead up to the end-Triassic mass extinction. Such a scenario implies expansion and shallowing of the oxygen minimum zone across a very broad area of northeastern Panthalassa, which potentially created a stressful environment for benthic metazoan communities. Studies of the pre-extinction interval from different sites across the globe are required to resolve the chronology and spatial distribution of processes that governed before the major environmental collapse that caused the ETE. Results from this study demonstrate that fluctuating anoxic and euxinic conditions could have been potentially responsible for reduced ecosystem stability before the onset of CAMP volcanism, at least at the regional scale.
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Affiliation(s)
- Ekaterina Larina
- Earth Sciences, University of Southern California, Los Angeles, USA.
| | - David J Bottjer
- Earth Sciences, University of Southern California, Los Angeles, USA
| | - Frank A Corsetti
- Earth Sciences, University of Southern California, Los Angeles, USA
| | | | | | - Jake V Bailey
- Earth Sciences, University of Minnesota, Minneapolis, USA
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26
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Bronzati M, Müller RT, Langer MC. Skull remains of the dinosaur Saturnalia tupiniquim (Late Triassic, Brazil): With comments on the early evolution of sauropodomorph feeding behaviour. PLoS One 2019; 14:e0221387. [PMID: 31490962 PMCID: PMC6730896 DOI: 10.1371/journal.pone.0221387] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 08/07/2019] [Indexed: 11/28/2022] Open
Abstract
Saturnalia tupiniquim is a sauropodomorph dinosaur from the Late Triassic (Carnian–c. 233 Ma) Santa Maria Formation of Brazil. Due to its phylogenetic position and age, it is important for studies focusing on the early evolution of both dinosaurs and sauropodomorphs. The osteology of Saturnalia has been described in a series of papers, but its cranial anatomy remains mostly unknown. Here, we describe the skull bones of one of its paratypes (only in the type-series to possess such remains) based on CT Scan data. The newly described elements allowed estimating the cranial length of Saturnalia and provide additional support for the presence of a reduced skull (i.e. two thirds of the femoral length) in this taxon, as typical of later sauropodomorphs. Skull reduction in Saturnalia could be related to an increased efficiency for predatory feeding behaviour, allowing fast movements of the head in order to secure small and elusive prey, a hypothesis also supported by data from its tooth and brain morphology. A principal co-ordinates analysis of the sauropodomorph jaw feeding apparatus shows marked shifts in morphospace occupation in different stages of the first 30 million years of their evolutionary history. One of these shifts is observed between non-plateosaurian and plateosaurian sauropodomorphs, suggesting that, despite also having an omnivorous diet, the feeding behaviour of some early Carnian sauropodomorphs, such as Saturnalia, was markedly different from that of later Triassic taxa. A second shift, between Late Triassic and Early Jurassic taxa, is congruent with a floral turnover hypothesis across the Triassic-Jurassic boundary.
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Affiliation(s)
- Mario Bronzati
- Laboratório de Paleontologia, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
- * E-mail: (MB); (MCL)
| | - Rodrigo T. Müller
- Centro de Apoio à Pesquisa Paleontológica, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Max C. Langer
- Laboratório de Paleontologia, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
- * E-mail: (MB); (MCL)
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Hu JJ, Xing YW, Su T, Huang YJ, Zhou ZK. Stomatal frequency of Quercus glauca from three material sources shows the same inverse response to atmospheric pCO2. ANNALS OF BOTANY 2019; 123:1147-1158. [PMID: 30861064 PMCID: PMC6612940 DOI: 10.1093/aob/mcz020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 02/01/2019] [Indexed: 05/27/2023]
Abstract
BACKGROUND AND AIMS The inverse correlation between atmospheric CO2 partial pressure (pCO2) and stomatal frequency in many plants has been widely used to estimate palaeo-CO2 levels. However, apparent discrepancies exist among the obtained estimates. This study attempts to find a potential proxy for palaeo-CO2 concentrations by analysing the stomatal frequency of Quercus glauca (section Cyclobalanopsis, Fagaceae), a dominant species in East Asian sub-tropical forests with abundant fossil relatives. METHODS Stomatal frequencies of Q. glauca from three material sources were analysed: seedlings grown in four climatic chambers with elevated CO2 ranging from 400 to 1300 ppm; extant samples collected from 14 field sites at altitudes ranging from 142 to 1555 m; and 18 herbarium specimens collected between 1930 and 2011. Stomatal frequency-pCO2 correlations were determined using samples from these three sources. KEY RESULTS An inverse correlation between stomatal frequency and pCO2 was found for Q. glauca through cross-validation of the three material sources. The combined calibration curves integrating data of extant altitudinal samples and historical herbarium specimens improved the reliability and accuracy of the curves. However, materials in the climatic chambers exhibited a weak response and relatively high stomatal frequency possibly due to insufficient treatment time. CONCLUSIONS A new inverse stomatal frequency-pCO2 correlation for Q. glauca was determined using samples from three sources. These three material types show the same response, indicating that Q. glauca is sensitive to atmospheric pCO2 and is an ideal proxy for palaeo-CO2 levels. Quercus glauca is a nearest living relative (NLR) of section Cyclobalanopsis fossils, which are widely distributed in the strata of East Asia ranging from the Eocene to Pliocene, thereby providing excellent materials to reconstruct the atmospheric CO2 concentration history of the Cenozoic. Quercus glauca will add to the variety of proxies that can be widely used in addition to Ginkgo and Metasequoia.
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Affiliation(s)
- Jin-Jin Hu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Yao-Wu Xing
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Tao Su
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Yong-Jiang Huang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Zhe-Kun Zhou
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
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Boyce CK, Zwieniecki MA. The prospects for constraining productivity through time with the whole-plant physiology of fossils. THE NEW PHYTOLOGIST 2019; 223:40-49. [PMID: 30304562 DOI: 10.1111/nph.15446] [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: 11/10/2017] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
Anatomically preserved fossils allow estimation of hydraulic parameters, potentially providing constraints on interpreting whole-plant physiology. However, different organ systems have typically been considered in isolation - a problem given common mismatches of high and low conductance components coupled in the hydraulic path of the same plant. A recent paper addressed the issue of how to handle resistance mismatches in fossil plant hydraulics, focusing on Carboniferous medullosan seed plants and arborescent lycopsids. Among other problems, however, a fundamental error was made: the transpiration stream consists of resistances in series (where resistances are additive and the component with the largest resistance can dominate the behavior of the system), but emphasis was instead placed on the lowest resistance, effectively treating the system as resistances in parallel (where the component with the smallest resistance will dominate the behavior). Instead of possessing high assimilation capacities to match high specific stem conductances, it is argued here that individual high conductance components in these Paleozoic plants are nonetheless associated with low whole-plant productivity, just as can be commonly seen in living plants. Resolution of how to handle these issues may have broad implications for the Earth system including geobiological feedbacks to rock weathering, atmospheric composition, and climate.
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Affiliation(s)
- C Kevin Boyce
- Geological Sciences, Stanford University, Stanford, CA, 94305, USA
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29
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Li HT, Yi TS, Gao LM, Ma PF, Zhang T, Yang JB, Gitzendanner MA, Fritsch PW, Cai J, Luo Y, Wang H, van der Bank M, Zhang SD, Wang QF, Wang J, Zhang ZR, Fu CN, Yang J, Hollingsworth PM, Chase MW, Soltis DE, Soltis PS, Li DZ. Origin of angiosperms and the puzzle of the Jurassic gap. NATURE PLANTS 2019; 5:461-470. [PMID: 31061536 DOI: 10.1038/s41477-019-0421-0] [Citation(s) in RCA: 331] [Impact Index Per Article: 66.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 04/02/2019] [Indexed: 05/19/2023]
Abstract
Angiosperms are by far the most species-rich clade of land plants, but their origin and early evolutionary history remain poorly understood. We reconstructed angiosperm phylogeny based on 80 genes from 2,881 plastid genomes representing 85% of extant families and all orders. With a well-resolved plastid tree and 62 fossil calibrations, we dated the origin of the crown angiosperms to the Upper Triassic, with major angiosperm radiations occurring in the Jurassic and Lower Cretaceous. This estimated crown age is substantially earlier than that of unequivocal angiosperm fossils, and the difference is here termed the 'Jurassic angiosperm gap'. Our time-calibrated plastid phylogenomic tree provides a highly relevant framework for future comparative studies of flowering plant evolution.
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Affiliation(s)
- Hong-Tao Li
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Ting-Shuang Yi
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Lian-Ming Gao
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Peng-Fei Ma
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Ting Zhang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Jun-Bo Yang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Matthew A Gitzendanner
- Florida Museum of Natural History, University of Florida, Gainesville, FL, USA
- Department of Biology, University of Florida, Gainesville, FL, USA
| | | | - Jie Cai
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Yang Luo
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Hong Wang
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Michelle van der Bank
- Department of Botany & Plant Biotechnology, University of Johannesburg, Johannesburg, South Africa
| | - Shu-Dong Zhang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Qing-Feng Wang
- Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China
| | - Jian Wang
- Queensland Herbarium, Department of Environment and Science, Brisbane Botanic Gardens, Toowong, Queensland, Australia
| | - Zhi-Rong Zhang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Chao-Nan Fu
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Jing Yang
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | | | - Mark W Chase
- Royal Botanic Gardens, Kew, UK
- Department of Environment and Agriculture, Curtin University, Bentley, Western Australia, Australia
| | - Douglas E Soltis
- Florida Museum of Natural History, University of Florida, Gainesville, FL, USA
- Department of Biology, University of Florida, Gainesville, FL, USA
- Genetics Institute, University of Florida, Gainesville, FL, USA
- Biodiversity Institute, University of Florida, Gainesville, FL, USA
| | - Pamela S Soltis
- Florida Museum of Natural History, University of Florida, Gainesville, FL, USA.
- Genetics Institute, University of Florida, Gainesville, FL, USA.
- Biodiversity Institute, University of Florida, Gainesville, FL, USA.
| | - De-Zhu Li
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.
- CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China.
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30
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Calosi P, Putnam HM, Twitchett RJ, Vermandele F. Marine Metazoan Modern Mass Extinction: Improving Predictions by Integrating Fossil, Modern, and Physiological Data. ANNUAL REVIEW OF MARINE SCIENCE 2019; 11:369-390. [PMID: 30216738 DOI: 10.1146/annurev-marine-010318-095106] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Evolution, extinction, and dispersion are fundamental processes affecting marine biodiversity. Until recently, studies of extant marine systems focused mainly on evolution and dispersion, with extinction receiving less attention. Past extinction events have, however, helped shape the evolutionary history of marine ecosystems, with ecological and evolutionary legacies still evident in modern seas. Current anthropogenic global changes increase extinction risk and pose a significant threat to marine ecosystems, which are critical for human use and sustenance. The evaluation of these threats and the likely responses of marine ecosystems requires a better understanding of evolutionary processes that affect marine ecosystems under global change. Here, we discuss how knowledge of ( a) changes in biodiversity of ancient marine ecosystems to past extinctions events, ( b) the patterns of sensitivity and biodiversity loss in modern marine taxa, and ( c) the physiological mechanisms underpinning species' sensitivity to global change can be exploited and integrated to advance our critical thinking in this area.
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Affiliation(s)
- Piero Calosi
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, Quebec G5L 3A1, Canada; ,
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island 02881, USA;
| | - Richard J Twitchett
- Department of Earth Sciences, Natural History Museum, London SW7 5BD, United Kingdom;
| | - Fanny Vermandele
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, Quebec G5L 3A1, Canada; ,
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31
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Haus MJ, Li M, Chitwood DH, Jacobs TW. Long-Distance and Trans-Generational Stomatal Patterning by CO 2 Across Arabidopsis Organs. FRONTIERS IN PLANT SCIENCE 2018; 9:1714. [PMID: 30559750 PMCID: PMC6287203 DOI: 10.3389/fpls.2018.01714] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/05/2018] [Indexed: 05/20/2023]
Abstract
Stomata control water loss and carbon dioxide uptake by both altering pore aperture and developmental patterning. Stomatal patterning is regulated by environmental factors including atmospheric carbon dioxide (p[CO2]), which is increasing globally at an unprecedented rate. Mature leaves are known to convey developmental cues to immature leaves in response to p[CO2], but the developmental mechanisms are unknown. To characterize changes in stomatal patterning resulting from signals moving from mature to developing leaves, we constructed a dual-chamber growth system in which rosette and cauline leaves of Arabidopsis thaliana were subjected to differing p[CO2]. Young rosette tissue was found to adjust stomatal index (SI, the proportion of stomata to total cell number) in response to both the current environment and the environment experienced by mature rosette tissue, whereas cauline leaves appear to be insensitive to p[CO2] treatment. It is likely that cauline leaves and cotyledons deploy mechanisms for controlling stomatal development that share common but also deploy distinctive mechanisms to that operating in rosette leaves. The effect of p[CO2] on stomatal development is retained in cotyledons of the next generation, however, this effect does not occur in pre-germination stomatal lineage cells but only after germination. Finally, these data suggest that p[CO2] affects regulation of stomatal development specifically through the development of satellite stomata (stomata induced by signals from a neighboring stomate) during spacing divisions and not the basal pathway. To our knowledge, this is the first report identifying developmental steps responsible for altered stomatal patterning to p[CO2] and its trans-generational inheritance.
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Affiliation(s)
- Miranda J. Haus
- Department of Plant Biology, University of Illinois at Urbana–Champaign, Urbana, IL, United States
- Department of Plant Biology, Michigan State University, East Lansing, MI, United States
| | - Mao Li
- Donald Danforth Plant Science Center, St. Louis, MO, United States
| | - Daniel H. Chitwood
- Department of Horticulture, Michigan State University, East Lansing, MI, United States
- Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, MI, United States
| | - Thomas W. Jacobs
- Department of Plant Biology, University of Illinois at Urbana–Champaign, Urbana, IL, United States
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Dunhill AM, Foster WJ, Azaele S, Sciberras J, Twitchett RJ. Modelling determinants of extinction across two Mesozoic hyperthermal events. Proc Biol Sci 2018; 285:rspb.2018.0404. [PMID: 30355705 DOI: 10.1098/rspb.2018.0404] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 10/08/2018] [Indexed: 11/12/2022] Open
Abstract
The Late Triassic and Early Toarcian extinction events are both associated with greenhouse warming events triggered by massive volcanism. These Mesozoic hyperthermals were responsible for the mass extinction of marine organisms and resulted in significant ecological upheaval. It has, however, been suggested that these events merely involved intensification of background extinction rates rather than significant shifts in the macroevolutionary regime and extinction selectivity. Here, we apply a multivariate modelling approach to a vast global database of marine organisms to test whether extinction selectivity varied through the Late Triassic and Early Jurassic. We show that these hyperthermals do represent shifts in the macroevolutionary regime and record different extinction selectivity compared to background intervals of the Late Triassic and Early Jurassic. The Late Triassic mass extinction represents a more profound change in selectivity than the Early Toarcian extinction but both events show a common pattern of selecting against pelagic predators and benthic photosymbiotic and suspension-feeding organisms, suggesting that these groups of organisms may be particularly vulnerable during episodes of global warming. In particular, the Late Triassic extinction represents a macroevolutionary regime change that is characterized by (i) the change in extinction selectivity between Triassic background intervals and the extinction event itself; and (ii) the differences in extinction selectivity between the Late Triassic and Early Jurassic as a whole.
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Affiliation(s)
| | - William J Foster
- Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Deutschland
| | - Sandro Azaele
- School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
| | - James Sciberras
- OnCorps, Exeter House, Lower Station Approach, Temple Meads, Bristol BS1 6QS, UK
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Foster GL, Hull P, Lunt DJ, Zachos JC. Placing our current 'hyperthermal' in the context of rapid climate change in our geological past. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0086. [PMID: 30177567 PMCID: PMC6127387 DOI: 10.1098/rsta.2017.0086] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/07/2018] [Indexed: 05/22/2023]
Abstract
'…there are known knowns. These are things we know that we know. There are known unknowns. That is to say, there are things that we know we don't know. But there are also unknown unknowns. There are things we don't know we don't know.' Donald Rumsfeld 12th February 2002.This article is part of a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'.
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Affiliation(s)
- Gavin L Foster
- School of Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, SO14 3ZH, UK
| | - Pincelli Hull
- Department of Geology and Geophysics, Yale University, Box 208109, New Haven, CT 06520-8109, USA
| | - Daniel J Lunt
- School of Geographical Sciences, University of Bristol, University Road, Clifton, Bristol BS8 1SS, UK
| | - James C Zachos
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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Gill FL, Hummel J, Sharifi AR, Lee AP, Lomax BH, Seyfullah L. Diets of giants: the nutritional value of sauropod diet during the Mesozoic. PALAEONTOLOGY 2018; 61:647-658. [PMID: 30147151 PMCID: PMC6099296 DOI: 10.1111/pala.12385] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 06/12/2018] [Indexed: 05/11/2023]
Abstract
A major uncertainty in estimating energy budgets and population densities of extinct animals is the carrying capacity of their ecosystems, constrained by net primary productivity (NPP) and its digestible energy content. The hypothesis that increases in NPP due to elevated atmospheric CO 2 contributed to the unparalleled size of the sauropods has recently been rejected, based on modern studies on herbivorous insects that imply a general, negative correlation of diet quality and increasing CO 2. However, the nutritional value of plants grown under elevated CO 2 levels might be very different for vertebrate megaherbivores than for insects. Here we show plant species-specific responses in metabolizable energy and nitrogen content, equivalent to a two-fold variation in daily food intake estimates for a typical sauropod, for dinosaur food plant analogues grown under CO 2 concentrations spanning estimates for Mesozoic atmospheric concentrations. Our results potentially rebut the hypothesis that constraints on sauropod diet quality were driven by Mesozoic CO 2 concentration.
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Affiliation(s)
- Fiona L. Gill
- School of Earth & EnvironmentUniversity of LeedsLeedsLS2 9JTUK
| | - Jürgen Hummel
- Department of Animal SciencesUniversity of GoettingenGoettingenGermany
| | - A. Reza Sharifi
- Department of Animal SciencesUniversity of GoettingenGoettingenGermany
| | - Alexandra P. Lee
- The School of BiosciencesThe University of NottinghamSutton Bonington Campus, Sutton BoningtonLeicestershireLE12 5RDUK
| | - Barry H. Lomax
- The School of BiosciencesThe University of NottinghamSutton Bonington Campus, Sutton BoningtonLeicestershireLE12 5RDUK
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35
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McElwain JC. Paleobotany and Global Change: Important Lessons for Species to Biomes from Vegetation Responses to Past Global Change. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:761-787. [PMID: 29719166 DOI: 10.1146/annurev-arplant-042817-040405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Human carbon use during the next century will lead to atmospheric carbon dioxide concentrations (pCO2) that have been unprecedented for the past 50-100+ million years according to fossil plant-based CO2 estimates. The paleobotanical record of plants offers key insights into vegetation responses to past global change, including suitable analogs for Earth's climatic future. Past global warming events have resulted in transient poleward migration at rates that are equivalent to the lowest climate velocities required for current taxa to keep pace with climate change. Paleobiome reconstructions suggest that the current tundra biome is the biome most threatened by global warming. The common occurrence of paleoforests at high polar latitudes when pCO2 was above 500 ppm suggests that the advance of woody shrub and tree taxa into tundra environments may be inevitable. Fossil pollen studies demonstrate the resilience of wet tropical forests to global change up to 700 ppm CO2, contrary to modeled predictions of the future. The paleobotanical record also demonstrates a high capacity for functional trait evolution as an additional strategy to migration and maintenance of a species' climate envelope in response to global change.
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Affiliation(s)
- Jennifer C McElwain
- Botany Department, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland;
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36
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Haworth M, Belcher CM, Killi D, Dewhirst RA, Materassi A, Raschi A, Centritto M. Impaired photosynthesis and increased leaf construction costs may induce floral stress during episodes of global warming over macroevolutionary timescales. Sci Rep 2018; 8:6206. [PMID: 29670149 PMCID: PMC6049339 DOI: 10.1038/s41598-018-24459-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 03/21/2018] [Indexed: 11/30/2022] Open
Abstract
Global warming events have coincided with turnover of plant species at intervals in Earth history. As mean global temperatures rise, the number, frequency and duration of heat-waves will increase. Ginkgo biloba was grown under controlled climatic conditions at two different day/night temperature regimes (25/20 °C and 35/30 °C) to investigate the impact of heat stress. Photosynthetic CO2-uptake and electron transport were reduced at the higher temperature, while rates of respiration were greater; suggesting that the carbon balance of the leaves was adversely affected. Stomatal conductance and the potential for evaporative cooling of the leaves was reduced at the higher temperature. Furthermore, the capacity of the leaves to dissipate excess energy was also reduced at 35/30 °C, indicating that photo-protective mechanisms were no longer functioning effectively. Leaf economics were adversely affected by heat stress, exhibiting an increase in leaf mass per area and leaf construction costs. This may be consistent with the selective pressures experienced by fossil Ginkgoales during intervals of global warming such as the Triassic - Jurassic boundary or Early Eocene Climatic Optimum. The physiological and morphological responses of the G. biloba leaves were closely interrelated; these relationships may be used to infer the leaf economics and photosynthetic/stress physiology of fossil plants.
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Affiliation(s)
- Matthew Haworth
- The Italian National Research Council - Tree and Timber Institute (CNR-IVALSA) Via Madonna del Piano 10, Sesto Fiorentino, 50019, Florence, Italy.
| | - Claire M Belcher
- University of Exeter wildFIRE Lab, Hatherly Labs Prince Wales Road Exeter, EX PS, Devon, England
| | - Dilek Killi
- Department of Agrifood Production and Environmental Sciences (DiSPAA), University of Florence Piazzale delle Cascine, 28 50144, Florence, Italy
| | - Rebecca A Dewhirst
- University of Exeter wildFIRE Lab, Hatherly Labs Prince Wales Road Exeter, EX PS, Devon, England
| | - Alessandro Materassi
- The Italian National Research Council - Institute of Biometeorology (CNR-IBIMET) Via Giovanni Caproni, 8 50145, Florence, Italy
| | - Antonio Raschi
- The Italian National Research Council - Institute of Biometeorology (CNR-IBIMET) Via Giovanni Caproni, 8 50145, Florence, Italy
| | - Mauro Centritto
- The Italian National Research Council - Tree and Timber Institute (CNR-IVALSA) Via Madonna del Piano 10, Sesto Fiorentino, 50019, Florence, Italy
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Wu G, Liu H, Hua L, Luo Q, Lin Y, He P, Feng S, Liu J, Ye Q. Differential Responses of Stomata and Photosynthesis to Elevated Temperature in Two Co-occurring Subtropical Forest Tree Species. FRONTIERS IN PLANT SCIENCE 2018; 9:467. [PMID: 29740458 PMCID: PMC5928911 DOI: 10.3389/fpls.2018.00467] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/23/2018] [Indexed: 05/03/2023]
Abstract
Global warming could increase leaf transpiration and soil evaporation, which can potentially cause water deficit to plants. As valves, leaf stomata can control plant water loss and carbon gain, particularly under water stress conditions. To investigate the responses of stomata to elevated temperature in Schima superba and Syzygium rehderianum, two co-occurring subtropical forest dominant tree species, functional traits related to gas exchange, stomatal anatomy, and drought resistance were measured under control and warming environment (ca. 2°C higher). We found that leaf water potential at both predawn and midday significantly decreased for the two species grown under warming conditions compared with those grown in the control environment. Warming resulted in significant decrease of stomatal size in S. rehderianum, but had no obvious effect on that of S. superba. By contrast, stomatal density of S. superba significantly decreased under warming conditions, while non-significant change was observed for S. rehderianum. In addition, warming significantly reduced photosynthetic rate, stomatal conductance, and stomatal sensitivity to leaf water potential of S. superba, but had non-significant effects on those of S. rehderianum. Overall, our results demonstrated that, confronting water deficit caused by elevated temperature, the two co-occurring subtropical tree species responded differently through the adjustment of stomatal morphology and photosynthetic function. Consequently, S. rehderianum was able to maintain similar carbon assimilation as under control environment, while S. superba showed a decrease in carbon gain that might bring adverse effect on its dominancy in subtropical forest community under future climate change.
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Affiliation(s)
- Guilin Wu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Hui Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Lei Hua
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Qi Luo
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Yixue Lin
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Pengcheng He
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Shiwei Feng
- College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China
| | - Juxiu Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
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38
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Large-scale sill emplacement in Brazil as a trigger for the end-Triassic crisis. Sci Rep 2018; 8:141. [PMID: 29317730 PMCID: PMC5760721 DOI: 10.1038/s41598-017-18629-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 12/13/2017] [Indexed: 11/20/2022] Open
Abstract
The end-Triassic is characterized by one of the largest mass extinctions in the Phanerozoic, coinciding with major carbon cycle perturbations and global warming. It has been suggested that the environmental crisis is linked to widespread sill intrusions during magmatism associated with the Central Atlantic Magmatic Province (CAMP). Sub-volcanic sills are abundant in two of the largest onshore sedimentary basins in Brazil, the Amazonas and Solimões basins, where they comprise up to 20% of the stratigraphy. These basins contain extensive deposits of carbonate and evaporite, in addition to organic-rich shales and major hydrocarbon reservoirs. Here we show that large scale volatile generation followed sill emplacement in these lithologies. Thermal modeling demonstrates that contact metamorphism in the two basins could have generated 88,000 Gt CO2. In order to constrain the timing of gas generation, zircon from two sills has been dated by the U-Pb CA-ID-TIMS method, resulting in 206Pb/238U dates of 201.477 ± 0.062 Ma and 201.470 ± 0.089 Ma. Our findings demonstrate synchronicity between the intrusive phase and the end-Triassic mass extinction, and provide a quantified degassing scenario for one of the most dramatic time periods in the history of Earth.
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39
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Ross-Gillespie V, Picker MD, Dallas HF, Day JA. The role of temperature in egg development of three aquatic insects Lestagella penicillata (Ephemeroptera), Aphanicercella scutata (Plecoptera), Chimarra ambulans (Trichoptera) from South Africa. J Therm Biol 2018; 71:158-170. [DOI: 10.1016/j.jtherbio.2017.11.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 11/09/2017] [Accepted: 11/12/2017] [Indexed: 10/18/2022]
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40
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Fredin O, Viola G, Zwingmann H, Sørlie R, Brönner M, Lie JE, Grandal EM, Müller A, Margreth A, Vogt C, Knies J. Correspondence: Reply to 'Challenges with dating weathering products to unravel ancient landscapes'. Nat Commun 2017; 8:1503. [PMID: 29138388 PMCID: PMC5686173 DOI: 10.1038/s41467-017-01468-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 09/19/2017] [Indexed: 11/09/2022] Open
Affiliation(s)
- Ola Fredin
- Geological Survey of Norway, Leiv Eirikssons vei 39, 7491, Trondheim, Norway.
- Department of Geography, Norwegian University of Science and Technology, 7491, Trondheim, Norway.
| | - Giulio Viola
- Department of Biological, Geological and Environmental Sciences-BiGeA, University of Bologna, 40126, Bologna, Italy
| | - Horst Zwingmann
- Department of Geology and Mineralogy, Kyoto University, Kitashirakawa Oiwake-cho, Kyoto, 606-8502, Japan
| | | | - Marco Brönner
- Geological Survey of Norway, Leiv Eirikssons vei 39, 7491, Trondheim, Norway
- Department of Petroleum Engineering and Applied Geophysics, Norwegian University of Science and Technology, 7491, Trondheim, Norway
| | | | | | - Axel Müller
- Natural History Museum, University of Oslo, 0318, Oslo, Norway
- Natural History Museum, London, SW7 5DB, UK
| | - Annina Margreth
- Geological Survey of Norway, Leiv Eirikssons vei 39, 7491, Trondheim, Norway
| | - Christoph Vogt
- ZEKAM/FB5 Geowissenschaften, University of Bremen, 28334, Bremen, Germany
| | - Jochen Knies
- Geological Survey of Norway, Leiv Eirikssons vei 39, 7491, Trondheim, Norway
- CAGE-Centre for Arctic Gas Hydrate, Environment and Climate, University of Tromsø, 9037, Tromsø, Norway
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41
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Belcher CM. The influence of leaf morphology on litter flammability and its utility for interpreting palaeofire. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0163. [PMID: 27216520 DOI: 10.1098/rstb.2015.0163] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/29/2016] [Indexed: 11/12/2022] Open
Abstract
Studies of palaeofire rely on quantifying the abundance of fossil charcoals in sediments to estimate changes in fire activity. However, gaining an understanding of the behaviour of palaeofires is also essential if we are to determine the palaeoecological impact of wildfires. Here, I use experimental approaches to explore relationships between litter fire behaviour and leaf traits that are observable in the fossil record. Fire calorimetry was used to assess the flammability of 15 species of conifer litter and indicated that leaf morphology related to litter bulk density and fuel load that determined the duration of burning and the total energy released. These data were applied to a fossil case study that couples estimates of palaeolitter fire behaviour to charcoal-based estimates of fire activity and observations of palaeoecological changes. The case study reveals that significant changes in fire activity and behaviour likely fed back to determine ecosystem composition. This work highlights that we can recognize and measure plant traits in the fossil record that relate to fire behaviour and therefore that further research is warranted towards estimating palaeofire behaviour as it can enhance our ability to interpret the palaeoecological impact of palaeofires throughout Earth's long evolutionary history.This article is part of the themed issue 'The interaction of fire and mankind'.
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Affiliation(s)
- Claire M Belcher
- wildFIRE Lab, Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter EX4 4PS, UK
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42
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Soh WK, Wright IJ, Bacon KL, Lenz TI, Steinthorsdottir M, Parnell AC, McElwain JC. Palaeo leaf economics reveal a shift in ecosystem function associated with the end-Triassic mass extinction event. NATURE PLANTS 2017; 3:17104. [PMID: 28714942 DOI: 10.1038/nplants.2017.104] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 06/09/2017] [Indexed: 06/07/2023]
Abstract
Climate change is likely to have altered the ecological functioning of past ecosystems, and is likely to alter functioning in the future; however, the magnitude and direction of such changes are difficult to predict. Here we use a deep-time case study to evaluate the impact of a well-constrained CO2-induced global warming event on the ecological functioning of dominant plant communities. We use leaf mass per area (LMA), a widely used trait in modern plant ecology, to infer the palaeoecological strategy of fossil plant taxa. We show that palaeo-LMA can be inferred from fossil leaf cuticles based on a tight relationship between LMA and cuticle thickness observed among extant gymnosperms. Application of this new palaeo-LMA proxy to fossil gymnosperms from East Greenland reveals significant shifts in the dominant ecological strategies of vegetation found across the Triassic-Jurassic transition. Late Triassic forests, dominated by low-LMA taxa with inferred high transpiration rates and short leaf lifespans, were replaced in the Early Jurassic by forests dominated by high-LMA taxa that were likely to have slower metabolic rates. We suggest that extreme CO2-induced global warming selected for taxa with high LMA associated with a stress-tolerant strategy and that adaptive plasticity in leaf functional traits such as LMA contributed to post-warming ecological success.
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Affiliation(s)
- W K Soh
- School of Biology and Environmental Science, Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - I J Wright
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - K L Bacon
- School of Geography, University of Leeds, Leeds LS2 9JT, UK
| | - T I Lenz
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - M Steinthorsdottir
- Department of Geological Sciences and Bolin Centre for Climate Research, Stockholm University, SE-109 61 Stockholm, Sweden
- Department of Paleobiology, Swedish Museum of Natural History, SE-104 05 Stockholm, Sweden
| | - A C Parnell
- School of Mathematics &Statistics, Insight Centre for Data Analytics, University College Dublin, Belfield, Dublin 4, Ireland
| | - J C McElwain
- School of Biology and Environmental Science, Earth Institute, University College Dublin, Belfield, Dublin 4, Ireland
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43
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Abstract
The Central Atlantic Magmatic Province (CAMP) has long been proposed as having a causal relationship with the end-Triassic extinction event (∼201.5 Ma). In North America and northern Africa, CAMP is preserved as multiple basaltic units interbedded with uppermost Triassic to lowermost Jurassic sediments. However, it has been unclear whether this apparent pulsing was a local feature, or if pulses in the intensity of CAMP volcanism characterized the emplacement of the province as a whole. Here, six geographically widespread Triassic-Jurassic records, representing varied paleoenvironments, are analyzed for mercury (Hg) concentrations and Hg/total organic carbon (Hg/TOC) ratios. Volcanism is a major source of mercury to the modern environment. Clear increases in Hg and Hg/TOC are observed at the end-Triassic extinction horizon, confirming that a volcanically induced global Hg cycle perturbation occurred at that time. The established correlation between the extinction horizon and lowest CAMP basalts allows this sedimentary Hg excursion to be stratigraphically tied to a specific flood basalt unit, strengthening the case for volcanic Hg as the driver of sedimentary Hg/TOC spikes. Additional Hg/TOC peaks are also documented between the extinction horizon and the Triassic-Jurassic boundary (separated by ∼200 ky), supporting pulsatory intensity of CAMP volcanism across the entire province and providing direct evidence for episodic volatile release during the initial stages of CAMP emplacement. Pulsatory volcanism, and associated perturbations in the ocean-atmosphere system, likely had profound implications for the rate and magnitude of the end-Triassic mass extinction and subsequent biotic recovery.
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44
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Yiotis C, Evans-Fitz.Gerald C, McElwain JC. Differences in the photosynthetic plasticity of ferns and Ginkgo grown in experimentally controlled low [O2]:[CO2] atmospheres may explain their contrasting ecological fate across the Triassic-Jurassic mass extinction boundary. ANNALS OF BOTANY 2017; 119:1385-1395. [PMID: 28334286 PMCID: PMC5604595 DOI: 10.1093/aob/mcx018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/01/2017] [Indexed: 05/22/2023]
Abstract
Background and Aims Fluctuations in [CO 2 ] have been widely studied as a potential driver of plant evolution; however, the role of a fluctuating [O 2 ]:[CO 2 ] ratio is often overlooked. The present study aimed to investigate the inherent physiological plasticity of early diverging, extant species following acclimation to an atmosphere similar to that across the Triassic-Jurassic mass extinction interval (TJB, approx. 200 Mya), a time of major ecological change. Methods Mature plants from two angiosperm ( Drimys winteri and Chloranthus oldhamii ), two monilophyte ( Osmunda claytoniana and Cyathea australis ) and one gymnosperm ( Ginkgo biloba ) species were grown for 2 months in replicated walk-in Conviron BDW40 chambers running at TJB treatment conditions of 16 % [O 2 ]-1900 ppm [CO 2 ] and ambient conditions of 21 % [O 2 ]-400 ppm [CO 2 ], and their physiological plasticity was assessed using gas exchange and chlorophyll fluorescence methods. Key Results TJB acclimation caused significant reductions in the maximum rate of carboxylation ( V Cmax ) and the maximum electron flow supporting ribulose-1,5-bisphosphate regeneration ( J max ) in all species, yet this downregulation had little effect on their light-saturated photosynthetic rate ( A sat ). Ginkgo was found to photorespire heavily under ambient conditions, while growth in low [O 2 ]:[CO 2 ] resulted in increased heat dissipation per reaction centre ( DI o / RC ), severe photodamage, as revealed by the species' decreased maximum efficiency of primary photochemistry ( F v / F m ) and decreased in situ photosynthetic electron flow ( Jsitu ). Conclusions It is argued that the observed photodamage reflects the inability of Ginkgo to divert excess photosynthetic electron flow to sinks other than the downregulated C 3 and the diminished C 2 cycles under low [O 2 ]:[CO 2 ]. This finding, coupled with the remarkable physiological plasticity of the ferns, provides insights into the underlying mechanism of Ginkgoales' near extinction and ferns' proliferation as atmospheric [CO 2 ] increased to maximum levels across the TJB.
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Affiliation(s)
- C. Yiotis
- Earth Institute, O’Brien Centre for Science, University College Dublin, Belfield, Ireland
- School of Biology and Environmental Science, University College Dublin, Belfield, Ireland
| | - C. Evans-Fitz.Gerald
- Earth Institute, O’Brien Centre for Science, University College Dublin, Belfield, Ireland
- School of Biology and Environmental Science, University College Dublin, Belfield, Ireland
| | - J. C. McElwain
- Earth Institute, O’Brien Centre for Science, University College Dublin, Belfield, Ireland
- School of Biology and Environmental Science, University College Dublin, Belfield, Ireland
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45
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Davies JHFL, Marzoli A, Bertrand H, Youbi N, Ernesto M, Schaltegger U. End-Triassic mass extinction started by intrusive CAMP activity. Nat Commun 2017; 8:15596. [PMID: 28561025 PMCID: PMC5460029 DOI: 10.1038/ncomms15596] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 04/12/2017] [Indexed: 11/09/2022] Open
Abstract
The end-Triassic extinction is one of the Phanerozoic's largest mass extinctions. This extinction is typically attributed to climate change associated with degassing of basalt flows from the central Atlantic magmatic province (CAMP). However, recent work suggests that the earliest known CAMP basalts occur above the extinction horizon and that climatic and biotic changes began before the earliest known CAMP eruptions. Here we present new high-precision U-Pb ages from CAMP mafic intrusive units, showing that magmatic activity was occurring ∼100 Kyr ago before the earliest known eruptions. We correlate the early magmatic activity with the onset of changes to the climatic and biotic records. We also report ages from sills in an organic rich sedimentary basin in Brazil that intrude synchronously with the extinction suggesting that degassing of these organics contributed to the climate change which drove the extinction. Our results indicate that the intrusive record from large igneous provinces may be more important for linking to mass extinctions than the eruptive record.
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Affiliation(s)
- J H F L Davies
- Département des sciences de la Terre, Université de Genève, Genève 1205, Switzerland
| | - A Marzoli
- Dipartimento di Geoscienze, Universitá di Padova, Padova 35131, Italy
| | - H Bertrand
- Laboratoire de Géologie de Lyon, ENS de Lyon, Université Lyon 1, CNRS, UMR 5276, Lyon 69364, France
| | - N Youbi
- Cadi Ayyad University, Faculty of Sciences-Semlalia, Department of Geology, Marrakech Box 28/5, Morocco.,Instituto Dom Luiz, Faculdade de Ciências, Universidade de Lisboa, Lisboa 1749-016, Portugal
| | - M Ernesto
- Departamento de Geofisica, Instituto Astronomico, Geofisico e Ciencias Atmosfericas, Universidade de São Paulo, Rua do Matão, 1226, São Paulo, CEP 05508-900, Brazil
| | - U Schaltegger
- Département des sciences de la Terre, Université de Genève, Genève 1205, Switzerland
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46
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Fredin O, Viola G, Zwingmann H, Sørlie R, Brönner M, Lie JE, Grandal EM, Müller A, Margreth A, Vogt C, Knies J. The inheritance of a Mesozoic landscape in western Scandinavia. Nat Commun 2017; 8:14879. [PMID: 28452366 PMCID: PMC5477494 DOI: 10.1038/ncomms14879] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 02/08/2017] [Indexed: 11/09/2022] Open
Abstract
In-situ weathered bedrock, saprolite, is locally found in Scandinavia, where it is commonly thought to represent pre-Pleistocene weathering possibly associated with landscape formation. The age of weathering, however, remains loosely constrained, which has an impact on existing geological and landscape evolution models and morphotectonic correlations. Here we provide new geochronological evidence that some of the low-altitude basement landforms on- and offshore southwestern Scandinavia are a rejuvenated geomorphological relic from Mesozoic times. K-Ar dating of authigenic, syn-weathering illite from saprolitic remnants constrains original basement exposure in the Late Triassic (221.3±7.0–206.2±4.2 Ma) through deep weathering in a warm climate and subsequent partial mobilization of the saprolitic mantle into the overlying sediment cascade system. The data support the bulk geomorphological development of west Scandinavia coastal basement rocks during the Mesozoic and later, long-lasting relative tectonic stability. Pleistocene glaciations played an additional geomorphological role, selectively stripping the landscape from the Mesozoic overburden and carving glacial landforms down to Plio–Pleistocene times. Saprolite K-Ar dating offers unprecedented possibilities to study past weathering and landscape evolution processes. The age of weathering inferred from bedrock saprolite local to Scandinavia remains loosely constrained. Here, via K-Ar dating of authigenic, syn-weathering illite from saprolitic remnants, the authors constrain weathering to the Late Triassic.
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Affiliation(s)
- Ola Fredin
- Geological Survey of Norway, Leiv Eirikssons Vei 39, 7491 Trondheim, Norway.,Department of Geography, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Giulio Viola
- Geological Survey of Norway, Leiv Eirikssons Vei 39, 7491 Trondheim, Norway.,Department of Geology and Mineral Resources Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Horst Zwingmann
- Department of Geology and Mineralogy, Kyoto University, Kitashirakawa Oiwake-cho, 606-8502 Kyoto, Japan
| | | | - Marco Brönner
- Geological Survey of Norway, Leiv Eirikssons Vei 39, 7491 Trondheim, Norway.,Department of Petroleum Engineering and Applied Geophysics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | | | | | - Axel Müller
- Natural History Museum, University of Oslo, 0318 Oslo, Norway.,Natural History Museum, London SW7 5BD, UK
| | - Annina Margreth
- Geological Survey of Norway, Leiv Eirikssons Vei 39, 7491 Trondheim, Norway
| | - Christoph Vogt
- ZEKAM/FB5 Geowissenschaften, University of Bremen, 28334 Bremen, Germany
| | - Jochen Knies
- Geological Survey of Norway, Leiv Eirikssons Vei 39, 7491 Trondheim, Norway.,CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, University of Tromsø, 9037 Tromsø, Norway
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47
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Oyston JW, Hughes M, Gerber S, Wills MA. Why should we investigate the morphological disparity of plant clades? ANNALS OF BOTANY 2016; 117:859-79. [PMID: 26658292 PMCID: PMC4845799 DOI: 10.1093/aob/mcv135] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/28/2015] [Accepted: 07/08/2015] [Indexed: 05/10/2023]
Abstract
BACKGROUND Disparity refers to the morphological variation in a sample of taxa, and is distinct from diversity or taxonomic richness. Diversity and disparity are fundamentally decoupled; many groups attain high levels of disparity early in their evolution, while diversity is still comparatively low. Diversity may subsequently increase even in the face of static or declining disparity by increasingly fine sub-division of morphological 'design' space (morphospace). Many animal clades reached high levels of disparity early in their evolution, but there have been few comparable studies of plant clades, despite their profound ecological and evolutionary importance. This study offers a prospective and some preliminary macroevolutionary analyses. METHODS Classical morphometric methods are most suitable when there is reasonable conservation of form, but lose traction where morphological differences become greater (e.g. in comparisons across higher taxa). Discrete character matrices offer one means to compare a greater diversity of forms. This study explores morphospaces derived from eight discrete data sets for major plant clades, and discusses their macroevolutionary implications. KEY RESULTS Most of the plant clades in this study show initial, high levels of disparity that approach or attain the maximum levels reached subsequently. These plant clades are characterized by an initial phase of evolution during which most regions of their empirical morphospaces are colonized. Angiosperms, palms, pines and ferns show remarkably little variation in disparity through time. Conifers furnish the most marked exception, appearing at relatively low disparity in the latest Carboniferous, before expanding incrementally with the radiation of successive, tightly clustered constituent sub-clades. CONCLUSIONS Many cladistic data sets can be repurposed for investigating the morphological disparity of plant clades through time, and offer insights that are complementary to more focused morphometric studies. The unique structural and ecological features of plants make them ideally suited to investigating intrinsic and extrinsic constraints on disparity.
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Affiliation(s)
- Jack W Oyston
- Milner Centre for Evolution, University of Bath, Bath BA2 7AY, UK
| | - Martin Hughes
- Department of Life Sciences, The Natural History Museum, London SW7 5BD, UK and
| | - Sylvain Gerber
- Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK
| | - Matthew A Wills
- Milner Centre for Evolution, University of Bath, Bath BA2 7AY, UK,
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48
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Guex J, Pilet S, Müntener O, Bartolini A, Spangenberg J, Schoene B, Sell B, Schaltegger U. Thermal erosion of cratonic lithosphere as a potential trigger for mass-extinction. Sci Rep 2016; 6:23168. [PMID: 27009463 PMCID: PMC4806358 DOI: 10.1038/srep23168] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/29/2016] [Indexed: 11/09/2022] Open
Abstract
The temporal coincidence between large igneous provinces (LIPs) and mass extinctions has led many to pose a causal relationship between the two. However, there is still no consensus on a mechanistic model that explains how magmatism leads to the turnover of terrestrial and marine plants, invertebrates and vertebrates. Here we present a synthesis of ammonite biostratigraphy, isotopic data and high precision U-Pb zircon dates from the Triassic-Jurassic (T-J) and Pliensbachian-Toarcian (Pl-To) boundaries demonstrating that these biotic crises are both associated with rapid change from an initial cool period to greenhouse conditions. We explain these transitions as a result of changing gas species emitted during the progressive thermal erosion of cratonic lithosphere by plume activity or internal heating of the lithosphere. Our petrological model for LIP magmatism argues that initial gas emission was dominated by sulfur liberated from sulfide-bearing cratonic lithosphere before CO2 became the dominant gas. This model offers an explanation of why LIPs erupted through oceanic lithosphere are not associated with climatic and biotic crises comparable to LIPs emitted through cratonic lithosphere.
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Affiliation(s)
- Jean Guex
- Institute of Earth Sciences, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland
| | - Sebastien Pilet
- Institute of Earth Sciences, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland
| | - Othmar Müntener
- Institute of Earth Sciences, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland
| | - Annachiara Bartolini
- Muséum National d'Histoire Naturelle, CNRS UMR 7207 Paleobiodiversité et Paléoenvironnements, CP38, 8 rue Buffon, F-75005 Paris, France
| | - Jorge Spangenberg
- Institute of Earth Surface Dynamics, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland
| | - Blair Schoene
- Department of Geosciences, Princeton University, 219 Guyot Hall, Princeton, New Jersey 08544, USA
| | - Bryan Sell
- Earth &Environmental Sciences, University of Geneva, Rue des Maraîchers 13, 1205 Geneva, Switzerland
| | - Urs Schaltegger
- Earth &Environmental Sciences, University of Geneva, Rue des Maraîchers 13, 1205 Geneva, Switzerland
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Abstract
ABSTRACT
The change in oceanic carbonate chemistry due to increased atmospheric PCO2 has caused pH to decline in marine surface waters, a phenomenon known as ocean acidification (OA). The effects of OA on organisms have been shown to be widespread among diverse taxa from a wide range of habitats. The majority of studies of organismal response to OA are in short-term exposures to future levels of PCO2. From such studies, much information has been gathered on plastic responses organisms may make in the future that are beneficial or harmful to fitness. Relatively few studies have examined whether organisms can adapt to negative-fitness consequences of plastic responses to OA. We outline major approaches that have been used to study the adaptive potential for organisms to OA, which include comparative studies and experimental evolution. Organisms that inhabit a range of pH environments (e.g. pH gradients at volcanic CO2 seeps or in upwelling zones) have great potential for studies that identify adaptive shifts that have occurred through evolution. Comparative studies have advanced our understanding of adaptation to OA by linking whole-organism responses with cellular mechanisms. Such optimization of function provides a link between genetic variation and adaptive evolution in tuning optimal function of rate-limiting cellular processes in different pH conditions. For example, in experimental evolution studies of organisms with short generation times (e.g. phytoplankton), hundreds of generations of growth under future conditions has resulted in fixed differences in gene expression related to acid–base regulation. However, biochemical mechanisms for adaptive responses to OA have yet to be fully characterized, and are likely to be more complex than simply changes in gene expression or protein modification. Finally, we present a hypothesis regarding an unexplored area for biochemical adaptation to ocean acidification. In this hypothesis, proteins and membranes exposed to the external environment, such as epithelial tissues, may be susceptible to changes in external pH. Such biochemical systems could be adapted to a reduced pH environment by adjustment of weak bonds in an analogous fashion to biochemical adaptation to temperature. Whether such biochemical adaptation to OA exists remains to be discovered.
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Affiliation(s)
- Jonathon H. Stillman
- Romberg Tiburon Center, Department of Biology, San Francisco State University, Tiburon, CA 94920, USA
- Department of Integrative Biology, University of California Berkeley, Berkeley, CA 94709, USA
| | - Adam W. Paganini
- Romberg Tiburon Center, Department of Biology, San Francisco State University, Tiburon, CA 94920, USA
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50
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Hu JJ, Xing YW, Turkington R, Jacques FMB, Su T, Huang YJ, Zhou ZK. A new positive relationship between pCO2 and stomatal frequency in Quercus guyavifolia (Fagaceae): a potential proxy for palaeo-CO2 levels. ANNALS OF BOTANY 2015; 115:777-88. [PMID: 25681824 PMCID: PMC4373289 DOI: 10.1093/aob/mcv007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 12/02/2014] [Accepted: 01/05/2015] [Indexed: 05/11/2023]
Abstract
BACKGROUND AND AIMS The inverse relationship between atmospheric CO2 partial pressure (pCO2) and stomatal frequency in many species of plants has been widely used to estimate palaeoatmospheric CO2 (palaeo-CO2) levels; however, the results obtained have been quite variable. This study attempts to find a potential new proxy for palaeo-CO2 levels by analysing stomatal frequency in Quercus guyavifolia (Q. guajavifolia, Fagaceae), an extant dominant species of sclerophyllous forests in the Himalayas with abundant fossil relatives. METHODS Stomatal frequency was analysed for extant samples of Q. guyavifolia collected from17 field sites at altitudes ranging between 2493 and 4497 m. Herbarium specimens collected between 1926 and 2011 were also examined. Correlations of pCO2-stomatal frequency were determined using samples from both sources, and these were then applied to Q. preguyavaefolia fossils in order to estimate palaeo-CO2 concentrations for two late-Pliocene floras in south-western China. KEY RESULTS In contrast to the negative correlations detected for most other species that have been studied, a positive correlation between pCO2 and stomatal frequency was determined in Q. guyavifolia sampled from both extant field collections and historical herbarium specimens. Palaeo-CO2 concentrations were estimated to be approx. 180-240 ppm in the late Pliocene, which is consistent with most other previous estimates. CONCLUSIONS A new positive relationship between pCO2 and stomatal frequency in Q. guyavifolia is presented, which can be applied to the fossils closely related to this species that are widely distributed in the late-Cenozoic strata in order to estimate palaeo-CO2 concentrations. The results show that it is valid to use a positive relationship to estimate palaeo-CO2 concentrations, and the study adds to the variety of stomatal density/index relationships that available for estimating pCO2. The physiological mechanisms underlying this positive response are unclear, however, and require further research.
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Affiliation(s)
- Jin-Jin Hu
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yao-Wu Xing
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Roy Turkington
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Frédéric M B Jacques
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tao Su
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yong-Jiang Huang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhe-Kun Zhou
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China, Institute of Systematic Botany, University of Zürich, Zürich 8008, Switzerland, Department of Botany, and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4 and University of Chinese Academy of Sciences, Beijing 100049, China
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