Quantifying Ecological Impacts of Mass Extinctions with Network Analysis of Fossil Communities
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On the Continuity of Background and Mass Extinction
Paleobiology, 29(4), 2003, pp. 455±467 On the continuity of background and mass extinction Steve C. Wang Abstract.ÐDo mass extinctions grade continuously into the background extinctions occurring throughout the history of life, or are they a fundamentally distinct phenomenon that cannot be explained by processes responsible for background extinction? Various criteria have been proposed for addressing this question, including approaches based on physical mechanisms, ecological se- lectivity, and statistical characterizations of extinction intensities. Here I propose a framework de®ning three types of continuity of mass and background extinc- tionsÐcontinuity of cause, continuity of effect, and continuity of magnitude. I test the third type of continuity with a statistical method based on kernel density estimation. Previous statistical ap- proaches typically have examined quantitative characteristics of mass extinctions (such as metrics of extinction intensity) and compared them with the distribution of such characteristics associated with background extinctions. If mass extinctions are outliers, or are separated by a gap from back- ground extinctions, the distinctness of mass extinctions is supported. In this paper I apply Silverman's Critical Bandwidth Test to test for the continuity of mass ex- tinctions by applying kernel density estimation and bootstrap modality testing. The method im- proves on existing work based on searching for gaps in histograms, in that it does not depend on arbitrary choices of parameters (such as bin widths for histograms), and provides a direct estimate of the signi®cance of continuities or gaps in observed extinction intensities. I am thus able to test rigorously whether differences between mass extinctions and background extinctions are statisti- cally signi®cant. -
Appendix 3.Pdf
A Geoconservation perspective on the trace fossil record associated with the end – Ordovician mass extinction and glaciation in the Welsh Basin Item Type Thesis or dissertation Authors Nicholls, Keith H. Citation Nicholls, K. (2019). A Geoconservation perspective on the trace fossil record associated with the end – Ordovician mass extinction and glaciation in the Welsh Basin. (Doctoral dissertation). University of Chester, United Kingdom. Publisher University of Chester Rights Attribution-NonCommercial-NoDerivatives 4.0 International Download date 26/09/2021 02:37:15 Item License http://creativecommons.org/licenses/by-nc-nd/4.0/ Link to Item http://hdl.handle.net/10034/622234 International Chronostratigraphic Chart v2013/01 Erathem / Era System / Period Quaternary Neogene C e n o z o i c Paleogene Cretaceous M e s o z o i c Jurassic M e s o z o i c Jurassic Triassic Permian Carboniferous P a l Devonian e o z o i c P a l Devonian e o z o i c Silurian Ordovician s a n u a F y r Cambrian a n o i t u l o v E s ' i k s w o Ichnogeneric Diversity k p e 0 10 20 30 40 50 60 70 S 1 3 5 7 9 11 13 15 17 19 21 n 23 r e 25 d 27 o 29 M 31 33 35 37 39 T 41 43 i 45 47 m 49 e 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 89 91 93 Number of Ichnogenera (Treatise Part W) Ichnogeneric Diversity 0 10 20 30 40 50 60 70 1 3 5 7 9 11 13 15 17 19 21 n 23 r e 25 d 27 o 29 M 31 33 35 37 39 T 41 43 i 45 47 m 49 e 51 53 55 57 59 61 c i o 63 z 65 o e 67 a l 69 a 71 P 73 75 77 79 81 83 n 85 a i r 87 b 89 m 91 a 93 C Number of Ichnogenera (Treatise Part W) -
Western North Greenland (Laurentia)
BULLETIN OF THE GEOLOGICAL SOCIETY OF DENMARK · VOL. 69 · 2021 Trilobite fauna of the Telt Bugt Formation (Cambrian Series 2–Miaolingian Series), western North Greenland (Laurentia) JOHN S. PEEL Peel, J.S. 2021. Trilobite fauna of the Telt Bugt Formation (Cambrian Series 2–Mi- aolingian Series), western North Greenland (Laurentia). Bulletin of the Geological Society of Denmark, Vol. 69, pp. 1–33. ISSN 2245-7070. https://doi.org/10.37570/bgsd-2021-69-01 Trilobites dominantly of middle Cambrian (Miaolingian Series, Wuliuan Stage) Geological Society of Denmark age are described from the Telt Bugt Formation of Daugaard-Jensen Land, western https://2dgf.dk North Greenland (Laurentia), which is a correlative of the Cape Wood Formation of Inglefield Land and Ellesmere Island, Nunavut. Four biozones are recognised in Received 6 July 2020 Daugaard-Jensen Land, representing the Delamaran and Topazan regional stages Accepted in revised form of the western USA. The basal Plagiura–Poliella Biozone, with Mexicella cf. robusta, 16 December 2020 Kochiella, Fieldaspis? and Plagiura?, straddles the Cambrian Series 2–Miaolingian Series Published online 20 January 2021 boundary. It is overlain by the Mexicella mexicana Biozone, recognised for the first time in Greenland, with rare specimens of Caborcella arrojosensis. The Glossopleura walcotti © 2021 the authors. Re-use of material is Biozone, with Glossopleura, Clavaspidella and Polypleuraspis, dominates the succes- permitted, provided this work is cited. sion in eastern Daugaard-Jensen Land but is seemingly not represented in the type Creative Commons License CC BY: section in western outcrops, likely reflecting the drastic thinning of the formation https://creativecommons.org/licenses/by/4.0/ towards the north-west. -
Northern England Serpukhovian (Early Namurian)
1 Northern England Serpukhovian (early Namurian) 2 farfield responses to southern hemisphere glaciation 3 M.H. STEPHENSON1, L. ANGIOLINI2, P. CÓZAR3, F. JADOUL2, M.J. LENG4, D. 4 MILLWARD5, S. CHENERY1 5 1British Geological Survey, Keyworth, Nottingham, NG12 5GG, United Kingdom 6 2Dipartimento di Scienze della Terra "A. Desio", Università degli Studi di Milano, Via 7 Mangiagalli 34, Milano, 20133, Italy 8 3Instituto de Geología Económica CSIC-UCM; Facultad de Ciencias Geológicas; 9 Departamento de Paleontología; C./ José Antonio Novais 228040-Madrid; Spain 10 4NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, 11 Nottingham, NG12 5GG, United Kingdom 12 5British Geological Survey, Murchison House, Edinburgh, United Kingdom 13 14 15 Word count 7967 16 7 figs 17 1 table 18 67 references 19 RUNNING HEADER: NAMURIAN FARFIELD GLACIATION REPONSE 1 20 Abstract: During the Serpukhovian (early Namurian) icehouse conditions were initiated 21 in the southern hemisphere; however nearfield evidence is inconsistent: glaciation 22 appears to have started in limited areas of eastern Australia in the earliest Serpukhovian, 23 followed by a long interglacial, whereas data from South America and Tibet suggest 24 glaciation throughout the Serpukhovian. New farfield data from the Woodland, 25 Throckley and Rowlands Gill boreholes in northern England allow this inconsistency to 26 be addressed. δ18O from well-preserved late Serpukhovian (late Pendleian to early 27 Arnsbergian) Woodland brachiopods vary between –3.4 and –6.3‰, and δ13C varies 28 between –2.0 and +3.2‰, suggesting a δ18O seawater (w) value of around –1.8‰ 29 VSMOW, and therefore an absence of widespread ice-caps. The organic carbon δ13C 30 upward increasing trend in the Throckley Borehole (Serpukhovian to Bashkirian; c. -
Lee-Riding-2018.Pdf
Earth-Science Reviews 181 (2018) 98–121 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Marine oxygenation, lithistid sponges, and the early history of Paleozoic T skeletal reefs ⁎ Jeong-Hyun Leea, , Robert Ridingb a Department of Geology and Earth Environmental Sciences, Chungnam National University, Daejeon 34134, Republic of Korea b Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996, USA ARTICLE INFO ABSTRACT Keywords: Microbial carbonates were major components of early Paleozoic reefs until coral-stromatoporoid-bryozoan reefs Cambrian appeared in the mid-Ordovician. Microbial reefs were augmented by archaeocyath sponges for ~15 Myr in the Reef gap early Cambrian, by lithistid sponges for the remaining ~25 Myr of the Cambrian, and then by lithistid, calathiid Dysoxia and pulchrilaminid sponges for the first ~25 Myr of the Ordovician. The factors responsible for mid–late Hypoxia Cambrian microbial-lithistid sponge reef dominance remain unclear. Although oxygen increase appears to have Lithistid sponge-microbial reef significantly contributed to the early Cambrian ‘Explosion’ of marine animal life, it was followed by a prolonged period dominated by ‘greenhouse’ conditions, as sea-level rose and CO2 increased. The mid–late Cambrian was unusually warm, and these elevated temperatures can be expected to have lowered oxygen solubility, and to have promoted widespread thermal stratification resulting in marine dysoxia and hypoxia. Greenhouse condi- tions would also have stimulated carbonate platform development, locally further limiting shallow-water cir- culation. Low marine oxygenation has been linked to episodic extinctions of phytoplankton, trilobites and other metazoans during the mid–late Cambrian. -
The Ediacaran–Cambrian Transition: the Emerging Record from Small Carbonaceous Fossils (Scfs)
38 The Ediacaran–Cambrian transition: the emerging record from Small Carbonaceous Fossils (SCFs) Ben J. Slater1, Thomas H.P. Harvey2, Romain Guilbaud3, Sebastian Willman1, Graham E. Budd1, Nicholas J. Butterfield4. 1Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, SE-75236 Uppsala, Sweden ([email protected]) 2School of Geography, Geology and the Environment, University of Leicester, Leicester LE1 7RH, UK 3Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK. 4Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK Abstract.––The most profound change in the fossil record is centered on the Ediacaran–Cambrian transition. Sediments deposited near to this boundary record the first complex trace fossils, the first animal biomineralizers and the earliest fossils of the major animal groups that came to define the subsequent Phanerozoic fossil record. Here we discuss how the emerging record of small carbonaceous fossils (SCFs) is shedding new light on unmineralized aspects of the biota from this critical evolutionary transition. The new SCFs record complements currently established records from trace fossils and biomineralized shelly-remains in reconstructing the broader scale macroevolutionary patterns of this transition, but via an entirely different taphonomic window. SCFs extend the record of multiple major animal groups, improve our picture of protistan diversity from this interval, and reveal new data on elements of the biota that span the Ediacaran–Cambrian boundary. Key words: small carbonaceous fossils; bilateria; Burgess Shale-type preservation; Ediacaran; Terreneuvian. The dramatic changes in the fossil record across subsequent Cambrian radiation (Butterfield, the Ediacaran–Cambrian transition seemingly 2003; Slater et al., 2018a). -
The Weeks Formation Konservat-Lagerstätte and the Evolutionary Transition of Cambrian Marine Life
Downloaded from http://jgs.lyellcollection.org/ by guest on October 1, 2021 Review focus Journal of the Geological Society Published Online First https://doi.org/10.1144/jgs2018-042 The Weeks Formation Konservat-Lagerstätte and the evolutionary transition of Cambrian marine life Rudy Lerosey-Aubril1*, Robert R. Gaines2, Thomas A. Hegna3, Javier Ortega-Hernández4,5, Peter Van Roy6, Carlo Kier7 & Enrico Bonino7 1 Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia 2 Geology Department, Pomona College, Claremont, CA 91711, USA 3 Department of Geology, Western Illinois University, 113 Tillman Hall, 1 University Circle, Macomb, IL 61455, USA 4 Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK 5 Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA 6 Department of Geology, Ghent University, Krijgslaan 281/S8, B-9000 Ghent, Belgium 7 Back to the Past Museum, Carretera Cancún, Puerto Morelos, Quintana Roo 77580, Mexico R.L.-A., 0000-0003-2256-1872; R.R.G., 0000-0002-3713-5764; T.A.H., 0000-0001-9067-8787; J.O.-H., 0000-0002- 6801-7373 * Correspondence: [email protected] Abstract: The Weeks Formation in Utah is the youngest (c. 499 Ma) and least studied Cambrian Lagerstätte of the western USA. It preserves a diverse, exceptionally preserved fauna that inhabited a relatively deep water environment at the offshore margin of a carbonate platform, resembling the setting of the underlying Wheeler and Marjum formations. However, the Weeks fauna differs significantly in composition from the other remarkable biotas of the Cambrian Series 3 of Utah, suggesting a significant Guzhangian faunal restructuring. -
Ediacaran and Cambrian Stratigraphy in Estonia: an Updated Review
Estonian Journal of Earth Sciences, 2017, 66, 3, 152–160 https://doi.org/10.3176/earth.2017.12 Ediacaran and Cambrian stratigraphy in Estonia: an updated review Tõnu Meidla Department of Geology, Institute of Ecology and Earth Sciences, Faculty of Science and Technology, University of Tartu, Ravila 14a, 50411 Tartu, Estonia; [email protected] Received 18 December 2015, accepted 18 May 2017, available online 6 July 2017 Abstract. Previous late Precambrian and Cambrian correlation charts of Estonia, summarizing the regional stratigraphic nomenclature of the 20th century, date back to 1997. The main aim of this review is updating these charts based on recent advances in the global Precambrian and Cambrian stratigraphy and new data from regions adjacent to Estonia. The term ‘Ediacaran’ is introduced for the latest Precambrian succession in Estonia to replace the formerly used ‘Vendian’. Correlation with the dated sections in adjacent areas suggests that only the latest 7–10 Ma of the Ediacaran is represented in the Estonian succession. The gap between the Ediacaran and Cambrian may be rather substantial. The global fourfold subdivision of the Cambrian System is introduced for Estonia. The lower boundary of Series 2 is drawn at the base of the Sõru Formation and the base of Series 3 slightly above the former lower boundary of the ‘Middle Cambrian’ in the Baltic region, marked by a gap in the Estonian succession. The base of the Furongian is located near the base of the Petseri Formation. Key words: Ediacaran, Cambrian, correlation chart, biozonation, regional stratigraphy, Estonia, East European Craton. INTRODUCTION The latest stratigraphic chart of the Cambrian System in Estonia (Mens & Pirrus 1997b, p. -
C0011 Carbon Isotope Stratigraphy
To protect the rights of the author(s) and publisher we inform you that this PDF is an uncorrected proof for internal business use only by the author(s), editor(s), reviewer(s), Elsevier and typesetter TNQ Books and Journals Pvt Ltd. It is not allowed to publish this proof online or in print. This proof copy is the copyright property of the publisher and is confidential until formal publication. Chapter 11 c0011 Carbon Isotope Stratigraphy M.R. Saltzman and E. Thomas Chapter Outline 11.1. Principles of Carbon Isotope Stratigraphy 221 11.3.3. Diagenesis 231 11.2. Spatial Heterogeneity of d13C of Dissolved 11.3.4. Global Versus Local Water Mass Signals 232 Inorganic Carbon 223 11.4. Correlation Potential and Excursions 232 11.3. Materials and Methods 224 11.5. Causes of Carbon Isotope Excursions 236 11.3.1. Depositional Setting: Deep (Pelagic) 11.6. Conclusion 237 Versus Shallow 224 Acknowledgments 237 11.3.2. Bulk Versus Component 231 References 237 s0010 11.1. PRINCIPLES OF CARBON ISOTOPE STRATIGRAPHY with the ocean-atmosphere system on longer time scales (105e106 years), contains carbon in both organic matter and p0015 The potential of marine carbonate d13C values to date and carbonate rock (limestones and dolomites) (Berner, 1990). 13 12 correlate rocks relies on the fact that their C/ C values have The carbon isotopic composition of CO2 in the atmo- p0025 varied over time, mainly as the result of partitioning of carbon sphere was about À6.4 & prior to anthropogenic fossil fuel between organic carbon and carbonate carbon reservoirs in the burning, close to the mantle value of about À6& (Sundquist lithosphere (e.g., Shackleton and Hall, 1984; Berner, 1990; and Visser, 2004) (Figure 11.1). -
GSSP) of the Drumian Stage (Cambrian) in the Drum Mountains, Utah, USA
Articles 8585 by Loren E. Babcock1, Richard A. Robison2, Margaret N. Rees3, Shanchi Peng4, and Matthew R. Saltzman1 The Global boundary Stratotype Section and Point (GSSP) of the Drumian Stage (Cambrian) in the Drum Mountains, Utah, USA 1 School of Earth Sciences, The Ohio State University, 125 South Oval Mall, Columbus, OH 43210, USA. Email: [email protected] and [email protected] 2 Department of Geology, University of Kansas, Lawrence, KS 66045, USA. Email: [email protected] 3 Department of Geoscience, University of Nevada, Las Vegas, Las Vegas, NV 89145, USA. Email: [email protected] 4 State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, China. Email: [email protected] The Global boundary Stratotype Section and Point correlated with precision through all major Cambrian regions. (GSSP) for the base of the Drumian Stage (Cambrian Among the methods that should be considered in the selection of a GSSP (Remane et al., 1996), biostratigraphic, chemostratigraphic, Series 3) is defined at the base of a limestone (cal- paleogeographic, facies-relationship, and sequence-stratigraphic cisiltite) layer 62 m above the base of the Wheeler For- information is available (e.g., Randolph, 1973; White, 1973; McGee, mation in the Stratotype Ridge section, Drum Moun- 1978; Dommer, 1980; Grannis, 1982; Robison, 1982, 1999; Rowell et al. 1982; Rees 1986; Langenburg et al., 2002a, 2002b; Babcock et tains, Utah, USA. The GSSP level contains the lowest al., 2004; Zhu et al., 2006); that information is summarized here. occurrence of the cosmopolitan agnostoid trilobite Pty- Voting members of the International Subcommission on Cam- chagnostus atavus (base of the P. -
Late Dresbachian (Late Cambrian) Biostratigraphy of North America
CHRISTINA LOCHMAN-BALK Department of Geosdence, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801 Late Dresbachian (Late Cambrian) Biostratigraphy of North America ABSTRACT bachian Aphelaspis Zone (Howell and Dresbachian time in the central Texas others, 1944) into an older Aphelaspis Zone section, with only a very short hiatus? before An examination of the taxonomic com- and a younger post-Aphelaspis Zone. the appearance of the Elvinia Zone fauna. position of the North American late Trilobites and brachiopods assigned by The short hiatus? refers to the well-defined Dresbachian faunules described to date Palmer to the Aphelaspis Zone are listed in faunal break and disconformity between the indicates that there is an Aphelaspis Zone Table 1. In the basal beds of the zone, Palmer Lion Mountain Sandstone Member of the faunal assemblage characteristic of the early Riley Formation and the Welge Sandstone half of the late Dresbachian Stage and a Member of the Wilberns Formation (Loch- TABLE 1. TRILOBITES ÄND BRACHIOPODS ASSIGNED TO Dunderbergia Zone faunal assemblage APHELASPIS ZONE, RILEY FORMATION, TEXAS, man, 1938; Freeman, 1969). characteristic of the later half. The diagnos- BY PALMER (1955) From 1951, Palmer was engaged in the tic elements of each of the assemblages are Aphelaspis walcotti study of the Late Cambrian faunas of the listed, and the biozones of the common Labiostria (now Aphelaspis) conveximavginata Great Basin and published late Dresbachian Labiostria (now Aphelaspis) platifrons trilobite genera are noted so that correct Dunderbergia variagranula faunal lists in Nolan and others (1956) and Eaaschella (now Glaphyraspis) omata intracontinental correlations may be made. -
Low-Latitude Origins of the Four Phanerozoic Evolutionary Faunas
bioRxiv preprint doi: https://doi.org/10.1101/866186; this version posted December 6, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Low-Latitude Origins of the Four Phanerozoic Evolutionary Faunas A. Rojas1*, J. Calatayud1, M. Kowalewski2, M. Neuman1, and M. Rosvall1 1Integrated Science Lab, Department of Physics, Umeå University, SE-901 87 Umeå, Sweden 5 2Florida Museum of Natural History, Division of Invertebrate Paleontology, University of Florida, Gainesville, FL 32611, USA *Correspondence to: [email protected] Abstract: Sepkoski’s hypothesis of Three Great Evolutionary Faunas that dominated 10 Phanerozoic oceans represents a foundational concept of macroevolutionary research. However, the hypothesis lacks spatial information and fails to recognize ecosystem changes in Mesozoic oceans. Using a multilayer network representation of fossil occurrences, we demonstrate that Phanerozoic oceans sequentially harbored four evolutionary faunas: Cambrian, Paleozoic, Mesozoic, and Cenozoic. These mega-assemblages all emerged at low latitudes and dispersed 15 out of the tropics. The Paleozoic–Mesozoic transition was abrupt, coincident with the Permian mass extinction, whereas the Mesozoic–Cenozoic transition was protracted, concurrent with gradual ecological shifts posited by the Mesozoic Marine Revolution. These findings support the notion that long-term ecological changes, historical contingencies, and major geological events all have played crucial roles in shaping the evolutionary history of marine animals. 20 One Sentence Summary: Network analysis reveals that Phanerozoic oceans harbored four evolutionary faunas with variable tempo and underlying causes.