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Climate Change and the Selective Signature of the Late Ordovician Mass Extinction
Climate change and the selective signature of the Late Ordovician mass extinction Seth Finnegana,b,1, Noel A. Heimc, Shanan E. Petersc, and Woodward W. Fischera aDivision of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125; bDepartment of Integrative Biology, University of California, 1005 Valley Life Sciences Bldg #3140, Berkeley, CA 94720; and cDepartment of Geoscience, University of Wisconsin-Madison, 1215 West Dayton Street, Madison, WI 53706 Edited by Richard K. Bambach, Smithsonian Institution, National Museum of Natural History, Washington, D.C., and accepted by the Editorial Board March 6, 2012 (received for review October 14, 2011) Selectivity patterns provide insights into the causes of ancient ex- sedimentary record (common cause hypothesis) (14). For the tinction events. The Late Ordovician mass extinction was related LOME, it is useful to split common cause into two hypotheses. to Gondwanan glaciation; however, it is still unclear whether ele- The eustatic common cause hypothesis postulates that Gondwa- vated extinction rates were attributable to record failure, habitat nan glaciation drove the extinction by lowering eustatic sea level, loss, or climatic cooling. We examined Middle Ordovician-Early thereby reducing the overall area of shallow marine habitats, Silurian North American fossil occurrences within a spatiotempo- reorganizing habitat mosaics, and disrupting larval dispersal cor- rally explicit stratigraphic framework that allowed us to quantify ridors (16–18). The climatic common cause hypothesis postulates rock record effects on a per-taxon basis and assay the interplay of that climate cooling, in addition to being ultimately responsible macrostratigraphic and macroecological variables in determining for sea-level drawdown and attendant habitat losses, had a direct extinction risk. -
History and Philosophy of Systematic Biology
History and Philosophy of Systematic Biology Bock, W. J. (1973) Philosophical foundations of classical evolutionary classification Systematic Zoology 22: 375-392 Part of a general symposium on "Contemporary Systematic Philosophies," there are some other interesting papers here. Brower, A. V. Z. (2000) Evolution Is Not a Necessary Assumption of Cladistics Cladistics 16: 143- 154 Dayrat, Benoit (2005) Ancestor-descendant relationships and the reconstruction of the Tree of Lif Paleobiology 31: 347-353 Donoghue, M.J. and J.W. Kadereit (1992) Walter Zimmermann and the growth of phylogenetic theory Systematic Biology 41: 74-84 Faith, D. P. and J. W. H. Trueman (2001) Towards an inclusive philosophy for phylogenetic inference Systematic Biology 50: 331-350 Gaffney, E. S. (1979) An introduction to the logic of phylogeny reconstruction, pp. 79-111 in Cracraft, J. and N. Eldredge (eds.) Phylogenetic Analysis and Paleontology Columbia University Press, New York. Gilmour, J. S. L. (1940) Taxonomy and philosophy, pp. 461-474 in J. Huxley (ed.) The New Systematics Oxford Hull, D. L. (1978) A matter of individuality Phil. of Science 45: 335-360 Hull, D. L. (1978) The principles of biological classification: the use and abuse of philosophy Hull, D. L. (1984) Cladistic theory: hypotheses that blur and grow, pp. 5-23 in T. Duncan and T. F. Stuessy (eds.) Cladistics: Perspectives on the Reconstruction of Evolutionary History Columbia University Press, New York * Hull, D. L. (1988) Science as a process: an evolutionary account of the social and conceptual development of science University of Chicago Press. An already classic work on the recent, violent history of systematics; used as data for Hull's general theories about scientific change. -
Origin and Evolution of Lycopods ""'"'Ill{
Origin and evolution of lycopods C. G. K. Ramanujam Ramanujam CGK 1992. Origin and evolution of lycopods. Palaeobotanist 41 51·57. The lycopods are known from as early as Sieginean Stage of the Lower Devonian. Lower and Middle Devonian lycopods were all herbaceous. Arborescent taxa appeared by Upper Devonian (e.g., Cyclostigma and Lepidosigillaria). The microphyllous foliage of lycopods seem to have originated from enations as well as telomic trusses. The lycopods auained peak of their evolution during the Upper Carboniferous. Towards the close of the Carboniferous and dawn of the Permian, with gradual dWindling and disappearance of swamps, the lepidodendrids suffered drastic decline numerically and phytogeographically. General aridity of the Triassic resulted in acute dwarfing as evidenced by Pleuromeia. This trend continued funher resulting in the highly telescoped Nathorstiana during the Cretaceous. The earlier lycopods were homosporous; heterospory appeared by Upper Devonian. Heterospory ran rampant in the Lepidodendrales. The ultimate in heterospory and the approach to seed habit could be witnessed in Lepidocarporz. Four discrete types of strobilus organization could be recognized by the Lower Carboniferous, viz., 1. Lepidostrobus type, 2. Mazocarpon type, 3. Achlamydocarpon type, and 4. Lepidocarpon type. Recent studies point towards the origin of lycopods along rwo different pathways, with both Zosterophyllopsida and Rhyniopsida representing the progenirors All available evidence show that Lycopsida constitutes a "Blind Alley" -
The Origin and Early Evolution of Plants on Land
review article The origin and early evolution of plants on land Paul Kenrick & Peter R. Crane . The origin and early evolution of land plants in the mid-Palaeozoic era, between about 480 and 360 million years ago, was an important event in the history of life, with far-reaching consequences for the evolution of terrestrial organisms and global environments. A recent surge of interest, catalysed by palaeobotanical discoveries and advances in the systematics of living plants, provides a revised perspective on the evolution of early land plants and suggests new directions for future research. The origin and early diversification of land plants marks an interval Eoembryophytic (mid-Ordovician [early Llanvirn: ϳ476 Myr] to of unparalleled innovation in the history of plant life. From a simple Early Silurian [late Llandovery: ϳ432 Myr])3. Spore tetrads (com- plant body consisting of only a few cells, land plants (liverworts, prising four membrane-bound spores; Fig. 2d) appear over a broad hornworts, mosses and vascular plants) evolved an elaborate two- geographic area in the mid-Ordovician and provide the first good phase life cycle and an extraordinary array of complex organs and evidence of land plants3,26,29. The combination of a decay-resistant tissue systems. Specialized sexual organs (gametangia), stems with wall (implying the presence of sporopollenin) and tetrahedral an intricate fluid transport mechanism (vascular tissue), structural configuration (implying haploid meiotic products) is diagnostic tissues (such as wood), epidermal structures for respiratory gas of land plants. The precise relationships of the spore producers exchange (stomates), leaves and roots of various kinds, diverse within land plants are controversial, but evidence of tetrads and spore-bearing organs (sporangia), seeds and the tree habit had all other spore types (such as dyads) in Late Silurian and Devonian evolved by the end of the Devonian period. -
SILURIAN TIMES NEWSLETTER of the INTERNATIONAL SUBCOMMISSION on SILURIAN STRATIGRAPHY (ISSS) (INTERNATIONAL COMMISSION on STRATIGRAPHY, ICS) No
SILURIAN TIMES NEWSLETTER OF THE INTERNATIONAL SUBCOMMISSION ON SILURIAN STRATIGRAPHY (ISSS) (INTERNATIONAL COMMISSION ON STRATIGRAPHY, ICS) No. 27 (for 2019) Edited by ZHAN Renbin INTERNATIONAL UNION OF GEOLOGICAL SCIENCES President: CHENG Qiuming (Canada) Vice-Presidents: Kristine ASCH (Germany) William CAVAZZA (Italy) Secretary General: Stanley C. FINNEY (USA) Treasurer: Hiroshi KITAZATO (Japan) INTERNATIONAL COMMISSION ON STRATIGRAPHY Chairman: David A.T. HARPER (UK) Vice-Chairman: Brian T. HUBER (USA) Secretary General: Philip GIBBARD (UK) SUBCOMMISSION ON SILURIAN STRATIGRAPHY Chairman: Petr ŠTORCH (Czech Republic) Vice-Chairman: Carlo CORRADINI (Italy) Secretary: ZHAN Renbin (China) Other titular members: Anna ANTOSHKINA (Russia) Carlton E. BRETT (USA) Bradley CRAMER (USA) David HOLLOWAY (Australia) Jisuo JIN (Canada) Anna KOZŁOWSKA (Poland) Jiří KŘÍŽ (Czech Republic) David K. LOYDELL (UK) Peep MÄNNIK (Estonia) Michael J. MELCHIN (Canada) Axel MUNNECKE (Germany) Silvio PERALTA (Argentina) Thijs VANDENBROUCKE (Belgium) WANG Yi (China) Živilė ŽIGAITĖ (Lithuania) Silurian Subcommission website: http://silurian.stratigraphy.org 1 CONTENTS CHAIRMAN’S CORNER 3 ANNUAL REPORT OF SILURIAN SUBCOMMISSION FOR 2019 7 INTERNATIONAL COMMISSION ON STRATGRAPHY STATUTES 15 REPORTS OF ACTIVITIES IN 2019 25 1. Report on the ISSS business meeting 2019 25 2. Report on the 15th International Symposium on Early/Lower Vertebrates 28 3. Report on the 13th International Symposium on the Ordovician System in conjunction with the 3rd Annual Meeting of IGCP 653 32 GUIDELINES FOR THE ISSS AWARD: KOREN' AWARD 33 ANNOUNCEMENTS OF MEETINGS and ACTIVITIES 34 1. Lithological Meeting: GEOLOGY OF REEFS 34 SILURIAN RESEARCH 2019: NEWS FROM THE MEMBERS 36 RECENT PUBLICATIONS ON THE SILURIAN RESEARCH 67 MEMBERSHIP NEWS 77 1. List of all Silurian workers and interested colleagues 77 2. -
Early Silurian Oceanic Episodes and Events
Journal of the Geological Society, London, Vol. 150, 1993, pp. 501-513, 3 figs. Printed in Northern Ireland Early Silurian oceanic episodes and events R. J. ALDRIDGE l, L. JEPPSSON 2 & K. J. DORNING 3 1Department of Geology, The University, Leicester LE1 7RH, UK 2Department of Historical Geology and Palaeontology, SiSlvegatan 13, S-223 62 Lund, Sweden 3pallab Research, 58 Robertson Road, Sheffield $6 5DX, UK Abstract: Biotic cycles in the early Silurian correlate broadly with postulated sea-level changes, but are better explained by a model that involves episodic changes in oceanic state. Primo episodes were characterized by cool high-latitude climates, cold oceanic bottom waters, and high nutrient supply which supported abundant and diverse planktonic communities. Secundo episodes were characterized by warmer high-latitude climates, salinity-dense oceanic bottom waters, low diversity planktonic communities, and carbonate formation in shallow waters. Extinction events occurred between primo and secundo episodes, with stepwise extinctions of taxa reflecting fluctuating conditions during the transition period. The pattern of turnover shown by conodont faunas, together with sedimentological information and data from other fossil groups, permit the identification of two cycles in the Llandovery to earliest Weniock interval. The episodes and events within these cycles are named: the Spirodden Secundo episode, the Jong Primo episode, the Sandvika event, the Malm#ykalven Secundo episode, the Snipklint Primo episode, and the lreviken event. Oceanic and climatic cyclicity is being increasingly semblages (Johnson et al. 1991b, p. 145). Using this recognized in the geological record, and linked to major and approach, they were able to detect four cycles within the minor sedimentological and biotic fluctuations. -
Revised Correlation of Silurian Provincial Series of North America with Global and Regional Chronostratigraphic Units 13 and D Ccarb Chemostratigraphy
Revised correlation of Silurian Provincial Series of North America with global and regional chronostratigraphic units 13 and d Ccarb chemostratigraphy BRADLEY D. CRAMER, CARLTON E. BRETT, MICHAEL J. MELCHIN, PEEP MA¨ NNIK, MARK A. KLEFF- NER, PATRICK I. MCLAUGHLIN, DAVID K. LOYDELL, AXEL MUNNECKE, LENNART JEPPSSON, CARLO CORRADINI, FRANK R. BRUNTON AND MATTHEW R. SALTZMAN Cramer, B.D., Brett, C.E., Melchin, M.J., Ma¨nnik, P., Kleffner, M.A., McLaughlin, P.I., Loydell, D.K., Munnecke, A., Jeppsson, L., Corradini, C., Brunton, F.R. & Saltzman, M.R. 2011: Revised correlation of Silurian Provincial Series of North America with global 13 and regional chronostratigraphic units and d Ccarb chemostratigraphy. Lethaia,Vol.44, pp. 185–202. Recent revisions to the biostratigraphic and chronostratigraphic assignment of strata from the type area of the Niagaran Provincial Series (a regional chronostratigraphic unit) have demonstrated the need to revise the chronostratigraphic correlation of the Silurian System of North America. Recently, the working group to restudy the base of the Wen- lock Series has developed an extremely high-resolution global chronostratigraphy for the Telychian and Sheinwoodian stages by integrating graptolite and conodont biostratigra- 13 phy with carbonate carbon isotope (d Ccarb) chemostratigraphy. This improved global chronostratigraphy has required such significant chronostratigraphic revisions to the North American succession that much of the Silurian System in North America is cur- rently in a state of flux and needs further refinement. This report serves as an update of the progress on recalibrating the global chronostratigraphic correlation of North Ameri- can Provincial Series and Stage boundaries in their type area. -
University of Birmingham Carbon Isotope (13Ccarb) and Facies
University of Birmingham Carbon isotope (13Ccarb) and facies variability at the Wenlock-Ludlow boundary (Silurian) of the Midland Platform, UK Blain, John Allan; Wheeley, James; Ray, David DOI: 10.1139/cjes-2015-0194 License: None: All rights reserved Document Version Peer reviewed version Citation for published version (Harvard): Blain, JA, Wheeley, J & Ray, D 2016, 'Carbon isotope (13Ccarb) and facies variability at the Wenlock-Ludlow boundary (Silurian) of the Midland Platform, UK', Canadian Journal of Earth Science. https://doi.org/10.1139/cjes-2015-0194 Link to publication on Research at Birmingham portal Publisher Rights Statement: Publisher Version of Record available at: http://dx.doi.org/10.1139/cjes-2015-0194 Validated Feb 2016 General rights Unless a licence is specified above, all rights (including copyright and moral rights) in this document are retained by the authors and/or the copyright holders. The express permission of the copyright holder must be obtained for any use of this material other than for purposes permitted by law. •Users may freely distribute the URL that is used to identify this publication. •Users may download and/or print one copy of the publication from the University of Birmingham research portal for the purpose of private study or non-commercial research. •User may use extracts from the document in line with the concept of ‘fair dealing’ under the Copyright, Designs and Patents Act 1988 (?) •Users may not further distribute the material nor use it for the purposes of commercial gain. Where a licence is displayed above, please note the terms and conditions of the licence govern your use of this document. -
Embryophytic Sporophytes in the Rhynie and Windyfield Cherts
Transactions of the Royal Society of Edinburgh: Earth Sciences http://journals.cambridge.org/TRE Additional services for Transactions of the Royal Society of Edinburgh: Earth Sciences: Email alerts: Click here Subscriptions: Click here Commercial reprints: Click here Terms of use : Click here Embryophytic sporophytes in the Rhynie and Windyeld cherts Dianne Edwards Transactions of the Royal Society of Edinburgh: Earth Sciences / Volume 94 / Issue 04 / December 2003, pp 397 - 410 DOI: 10.1017/S0263593300000778, Published online: 26 July 2007 Link to this article: http://journals.cambridge.org/abstract_S0263593300000778 How to cite this article: Dianne Edwards (2003). Embryophytic sporophytes in the Rhynie and Windyeld cherts. Transactions of the Royal Society of Edinburgh: Earth Sciences, 94, pp 397-410 doi:10.1017/S0263593300000778 Request Permissions : Click here Downloaded from http://journals.cambridge.org/TRE, IP address: 131.251.254.13 on 25 Feb 2014 Transactions of the Royal Society of Edinburgh: Earth Sciences, 94, 397–410, 2004 (for 2003) Embryophytic sporophytes in the Rhynie and Windyfield cherts Dianne Edwards ABSTRACT: Brief descriptions and comments on relationships are given for the seven embryo- phytic sporophytes in the cherts at Rhynie, Aberdeenshire, Scotland. They are Rhynia gwynne- vaughanii Kidston & Lang, Aglaophyton major D. S. Edwards, Horneophyton lignieri Barghoorn & Darrah, Asteroxylon mackiei Kidston & Lang, Nothia aphylla Lyon ex Høeg, Trichopherophyton teuchansii Lyon & Edwards and Ventarura lyonii Powell, Edwards & Trewin. The superb preserva- tion of the silica permineralisations produced in the hot spring environment provides remarkable insights into the anatomy of early land plants which are not available from compression fossils and other modes of permineralisation. -
(Silurian) Anoxic Palaeo-Depressions at the Western Margin of the Murzuq Basin (Southwest Libya), Based on Gamma-Ray Spectrometry in Surface Exposures
GeoArabia, Vol. 11, No. 3, 2006 Gulf PetroLink, Bahrain Identification of early Llandovery (Silurian) anoxic palaeo-depressions at the western margin of the Murzuq Basin (southwest Libya), based on gamma-ray spectrometry in surface exposures Nuri Fello, Sebastian Lüning, Petr Štorch and Jonathan Redfern ABSTRACT Following the melting of the Gondwanan icecap and the resulting postglacial sea- level rise, organic-rich shales were deposited in shelfal palaeo-depressions across North Africa and Arabia during the latest Ordovician to earliest Silurian. The unit is absent on palaeohighs that were flooded only later when the anoxic event had already ended. The regional distribution of the Silurian black shale is now well-known for the subsurface of the central parts of the Murzuq Basin, in Libya, where many exploration wells have been drilled and where the shale represents the main hydrocarbon source rock. On well logs, the Silurian black shale is easily recognisable due to increased uranium concentrations and, therefore, elevated gamma-ray values. The uranium in the shales “precipitated” under oxygen- reduced conditions and generally a linear relationship between uranium and organic content is developed. The distribution of the Silurian organic-rich shales in the outcrop belts surrounding the Murzuq Basin has been long unknown because Saharan surface weathering has commonly destroyed the organic matter and black colour of the shales, making it complicated to identify the previously organic-rich unit in the field. In an attempt to distinguish (previously) organic-rich from organically lean shales at outcrop, seven sections that straddle the Ordovician-Silurian boundary were measured by portable gamma-ray spectrometer along the outcrops of the western margin of the Murzuq Basin. -
Ordovician Land Plants and Fungi from Douglas Dam, Tennessee
PROOF The Palaeobotanist 68(2019): 1–33 The Palaeobotanist 68(2019): xxx–xxx 0031–0174/2019 0031–0174/2019 Ordovician land plants and fungi from Douglas Dam, Tennessee GREGORY J. RETALLACK Department of Earth Sciences, University of Oregon, Eugene, OR 97403, USA. *Email: gregr@uoregon. edu (Received 09 September, 2019; revised version accepted 15 December, 2019) ABSTRACT The Palaeobotanist 68(1–2): Retallack GJ 2019. Ordovician land plants and fungi from Douglas Dam, Tennessee. The Palaeobotanist 68(1–2): xxx–xxx. 1–33. Ordovician land plants have long been suspected from indirect evidence of fossil spores, plant fragments, carbon isotopic studies, and paleosols, but now can be visualized from plant compressions in a Middle Ordovician (Darriwilian or 460 Ma) sinkhole at Douglas Dam, Tennessee, U. S. A. Five bryophyte clades and two fungal clades are represented: hornwort (Casterlorum crispum, new form genus and species), liverwort (Cestites mirabilis Caster & Brooks), balloonwort (Janegraya sibylla, new form genus and species), peat moss (Dollyphyton boucotii, new form genus and species), harsh moss (Edwardsiphyton ovatum, new form genus and species), endomycorrhiza (Palaeoglomus strotheri, new species) and lichen (Prototaxites honeggeri, new species). The Douglas Dam Lagerstätte is a benchmark assemblage of early plants and fungi on land. Ordovician plant diversity now supports the idea that life on land had increased terrestrial weathering to induce the Great Ordovician Biodiversification Event in the sea and latest Ordovician (Hirnantian) -
Palynology of the Middle Ordovician Hawaz Formation in the Murzuq Basin, South-West Libya
This is a repository copy of Palynology of the Middle Ordovician Hawaz Formation in the Murzuq Basin, south-west Libya. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/125997/ Version: Accepted Version Article: Abuhmida, F.H. and Wellman, C.H. (2017) Palynology of the Middle Ordovician Hawaz Formation in the Murzuq Basin, south-west Libya. Palynology, 41. pp. 31-56. ISSN 0191-6122 https://doi.org/10.1080/01916122.2017.1356393 Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Palynology of the Middle Ordovician Hawaz Formation in the Murzuq Basin, southwest Libya Faisal H. Abuhmidaa*, Charles H. Wellmanb aLibyan Petroleum Institute, Tripoli, Libya P.O. Box 6431, bUniversity of Sheffield, Department of Animal and Plant Sciences, Alfred Denny Building, Western Bank, Sheffield, S10 2TN, UK Twenty nine core and seven cuttings samples were collected from two boreholes penetrating the Middle Ordovician Hawaz Formation in the Murzuq Basin, southwest Libya.